diff options
Diffstat (limited to 'fs')
49 files changed, 4272 insertions, 603 deletions
diff --git a/fs/Kconfig b/fs/Kconfig index 7385e54be4b9..6b40fd8d719e 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -67,6 +67,7 @@ source "fs/quota/Kconfig" source "fs/autofs4/Kconfig" source "fs/fuse/Kconfig" +source "fs/overlayfs/Kconfig" menu "Caches" diff --git a/fs/Makefile b/fs/Makefile index 47ac07bb4acc..b5954404e02d 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -104,6 +104,7 @@ obj-$(CONFIG_QNX6FS_FS) += qnx6/ obj-$(CONFIG_AUTOFS4_FS) += autofs4/ obj-$(CONFIG_ADFS_FS) += adfs/ obj-$(CONFIG_FUSE_FS) += fuse/ +obj-$(CONFIG_OVERLAY_FS) += overlayfs/ obj-$(CONFIG_UDF_FS) += udf/ obj-$(CONFIG_SUN_OPENPROMFS) += openpromfs/ obj-$(CONFIG_OMFS_FS) += omfs/ diff --git a/fs/afs/dir.c b/fs/afs/dir.c index 529300327f45..5479af6de6ce 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -26,7 +26,7 @@ static int afs_readdir(struct file *file, struct dir_context *ctx); static int afs_d_revalidate(struct dentry *dentry, unsigned int flags); static int afs_d_delete(const struct dentry *dentry); static void afs_d_release(struct dentry *dentry); -static int afs_lookup_filldir(void *_cookie, const char *name, int nlen, +static int afs_lookup_filldir(struct dir_context *ctx, const char *name, int nlen, loff_t fpos, u64 ino, unsigned dtype); static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl); @@ -391,10 +391,11 @@ static int afs_readdir(struct file *file, struct dir_context *ctx) * - if afs_dir_iterate_block() spots this function, it'll pass the FID * uniquifier through dtype */ -static int afs_lookup_filldir(void *_cookie, const char *name, int nlen, - loff_t fpos, u64 ino, unsigned dtype) +static int afs_lookup_filldir(struct dir_context *ctx, const char *name, + int nlen, loff_t fpos, u64 ino, unsigned dtype) { - struct afs_lookup_cookie *cookie = _cookie; + struct afs_lookup_cookie *cookie = + container_of(ctx, struct afs_lookup_cookie, ctx); _enter("{%s,%u},%s,%u,,%llu,%u", cookie->name.name, cookie->name.len, name, nlen, diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig index a66768ebc8d1..3def5122904a 100644 --- a/fs/btrfs/Kconfig +++ b/fs/btrfs/Kconfig @@ -1,5 +1,6 @@ config BTRFS_FS tristate "Btrfs filesystem support" + select LIBCRC32C select CRYPTO select CRYPTO_CRC32C select ZLIB_INFLATE diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 3e16042338e4..35696ba0318e 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -682,23 +682,6 @@ out: return ret; } -/* copy of check_sticky in fs/namei.c() -* It's inline, so penalty for filesystems that don't use sticky bit is -* minimal. -*/ -static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode) -{ - kuid_t fsuid = current_fsuid(); - - if (!(dir->i_mode & S_ISVTX)) - return 0; - if (uid_eq(inode->i_uid, fsuid)) - return 0; - if (uid_eq(dir->i_uid, fsuid)) - return 0; - return !capable(CAP_FOWNER); -} - /* copy of may_delete in fs/namei.c() * Check whether we can remove a link victim from directory dir, check * whether the type of victim is right. @@ -734,8 +717,7 @@ static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir) return error; if (IS_APPEND(dir)) return -EPERM; - if (btrfs_check_sticky(dir, victim->d_inode)|| - IS_APPEND(victim->d_inode)|| + if (check_sticky(dir, victim->d_inode) || IS_APPEND(victim->d_inode) || IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode)) return -EPERM; if (isdir) { diff --git a/fs/cachefiles/bind.c b/fs/cachefiles/bind.c index 622f4696e484..5b99bafc31d1 100644 --- a/fs/cachefiles/bind.c +++ b/fs/cachefiles/bind.c @@ -124,7 +124,6 @@ static int cachefiles_daemon_add_cache(struct cachefiles_cache *cache) /* check parameters */ ret = -EOPNOTSUPP; if (!root->d_inode || - !root->d_inode->i_op || !root->d_inode->i_op->lookup || !root->d_inode->i_op->mkdir || !root->d_inode->i_op->setxattr || diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c index ca65f39dc8dc..c0a681705104 100644 --- a/fs/cachefiles/namei.c +++ b/fs/cachefiles/namei.c @@ -391,12 +391,12 @@ try_again: path.dentry = dir; path_to_graveyard.mnt = cache->mnt; path_to_graveyard.dentry = cache->graveyard; - ret = security_path_rename(&path, rep, &path_to_graveyard, grave); + ret = security_path_rename(&path, rep, &path_to_graveyard, grave, 0); if (ret < 0) { cachefiles_io_error(cache, "Rename security error %d", ret); } else { ret = vfs_rename(dir->d_inode, rep, - cache->graveyard->d_inode, grave, NULL); + cache->graveyard->d_inode, grave, NULL, 0); if (ret != 0 && ret != -ENOMEM) cachefiles_io_error(cache, "Rename failed with error %d", ret); @@ -779,8 +779,7 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, } ret = -EPERM; - if (!subdir->d_inode->i_op || - !subdir->d_inode->i_op->setxattr || + if (!subdir->d_inode->i_op->setxattr || !subdir->d_inode->i_op->getxattr || !subdir->d_inode->i_op->lookup || !subdir->d_inode->i_op->mkdir || diff --git a/fs/compat.c b/fs/compat.c index 6af20de2c1a3..14da9b327ffa 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -837,10 +837,12 @@ struct compat_readdir_callback { int result; }; -static int compat_fillonedir(void *__buf, const char *name, int namlen, - loff_t offset, u64 ino, unsigned int d_type) +static int compat_fillonedir(struct dir_context *ctx, const char *name, + int namlen, loff_t offset, u64 ino, + unsigned int d_type) { - struct compat_readdir_callback *buf = __buf; + struct compat_readdir_callback *buf = + container_of(ctx, struct compat_readdir_callback, ctx); struct compat_old_linux_dirent __user *dirent; compat_ulong_t d_ino; @@ -905,11 +907,12 @@ struct compat_getdents_callback { int error; }; -static int compat_filldir(void *__buf, const char *name, int namlen, +static int compat_filldir(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct compat_linux_dirent __user * dirent; - struct compat_getdents_callback *buf = __buf; + struct compat_getdents_callback *buf = + container_of(ctx, struct compat_getdents_callback, ctx); compat_ulong_t d_ino; int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) + namlen + 2, sizeof(compat_long_t)); @@ -991,11 +994,13 @@ struct compat_getdents_callback64 { int error; }; -static int compat_filldir64(void * __buf, const char * name, int namlen, loff_t offset, - u64 ino, unsigned int d_type) +static int compat_filldir64(struct dir_context *ctx, const char *name, + int namlen, loff_t offset, u64 ino, + unsigned int d_type) { struct linux_dirent64 __user *dirent; - struct compat_getdents_callback64 *buf = __buf; + struct compat_getdents_callback64 *buf = + container_of(ctx, struct compat_getdents_callback64, ctx); int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1, sizeof(u64)); u64 off; diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c index a81147e2e4ef..4d24d17bcfc1 100644 --- a/fs/compat_binfmt_elf.c +++ b/fs/compat_binfmt_elf.c @@ -88,6 +88,11 @@ static void cputime_to_compat_timeval(const cputime_t cputime, #define ELF_HWCAP COMPAT_ELF_HWCAP #endif +#ifdef COMPAT_ELF_HWCAP2 +#undef ELF_HWCAP2 +#define ELF_HWCAP2 COMPAT_ELF_HWCAP2 +#endif + #ifdef COMPAT_ARCH_DLINFO #undef ARCH_DLINFO #define ARCH_DLINFO COMPAT_ARCH_DLINFO diff --git a/fs/dcache.c b/fs/dcache.c index c345f5f2b508..1b349b56839f 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2481,12 +2481,14 @@ static void switch_names(struct dentry *dentry, struct dentry *target) dentry->d_name.name = dentry->d_iname; } else { /* - * Both are internal. Just copy target to dentry + * Both are internal. */ - memcpy(dentry->d_iname, target->d_name.name, - target->d_name.len + 1); - dentry->d_name.len = target->d_name.len; - return; + unsigned int i; + BUILD_BUG_ON(!IS_ALIGNED(DNAME_INLINE_LEN, sizeof(long))); + for (i = 0; i < DNAME_INLINE_LEN / sizeof(long); i++) { + swap(((long *) &dentry->d_iname)[i], + ((long *) &target->d_iname)[i]); + } } } swap(dentry->d_name.len, target->d_name.len); @@ -2543,13 +2545,15 @@ static void dentry_unlock_parents_for_move(struct dentry *dentry, * __d_move - move a dentry * @dentry: entry to move * @target: new dentry + * @exchange: exchange the two dentries * * Update the dcache to reflect the move of a file name. Negative * dcache entries should not be moved in this way. Caller must hold * rename_lock, the i_mutex of the source and target directories, * and the sb->s_vfs_rename_mutex if they differ. See lock_rename(). */ -static void __d_move(struct dentry * dentry, struct dentry * target) +static void __d_move(struct dentry *dentry, struct dentry *target, + bool exchange) { if (!dentry->d_inode) printk(KERN_WARNING "VFS: moving negative dcache entry\n"); @@ -2571,8 +2575,15 @@ static void __d_move(struct dentry * dentry, struct dentry * target) __d_drop(dentry); __d_rehash(dentry, d_hash(target->d_parent, target->d_name.hash)); - /* Unhash the target: dput() will then get rid of it */ + /* + * Unhash the target (d_delete() is not usable here). If exchanging + * the two dentries, then rehash onto the other's hash queue. + */ __d_drop(target); + if (exchange) { + __d_rehash(target, + d_hash(dentry->d_parent, dentry->d_name.hash)); + } list_del(&dentry->d_child); list_del(&target->d_child); @@ -2599,6 +2610,8 @@ static void __d_move(struct dentry * dentry, struct dentry * target) write_seqcount_end(&dentry->d_seq); dentry_unlock_parents_for_move(dentry, target); + if (exchange) + fsnotify_d_move(target); spin_unlock(&target->d_lock); fsnotify_d_move(dentry); spin_unlock(&dentry->d_lock); @@ -2616,11 +2629,30 @@ static void __d_move(struct dentry * dentry, struct dentry * target) void d_move(struct dentry *dentry, struct dentry *target) { write_seqlock(&rename_lock); - __d_move(dentry, target); + __d_move(dentry, target, false); write_sequnlock(&rename_lock); } EXPORT_SYMBOL(d_move); +/* + * d_exchange - exchange two dentries + * @dentry1: first dentry + * @dentry2: second dentry + */ +void d_exchange(struct dentry *dentry1, struct dentry *dentry2) +{ + write_seqlock(&rename_lock); + + WARN_ON(!dentry1->d_inode); + WARN_ON(!dentry2->d_inode); + WARN_ON(IS_ROOT(dentry1)); + WARN_ON(IS_ROOT(dentry2)); + + __d_move(dentry1, dentry2, true); + + write_sequnlock(&rename_lock); +} + /** * d_ancestor - search for an ancestor * @p1: ancestor dentry @@ -2668,7 +2700,7 @@ static struct dentry *__d_unalias(struct inode *inode, m2 = &alias->d_parent->d_inode->i_mutex; out_unalias: if (likely(!d_mountpoint(alias))) { - __d_move(alias, dentry); + __d_move(alias, dentry, false); ret = alias; } out_err: diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index 03df50211c48..121a94876d40 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -76,11 +76,11 @@ struct ecryptfs_getdents_callback { /* Inspired by generic filldir in fs/readdir.c */ static int -ecryptfs_filldir(void *dirent, const char *lower_name, int lower_namelen, - loff_t offset, u64 ino, unsigned int d_type) +ecryptfs_filldir(struct dir_context *ctx, const char *lower_name, + int lower_namelen, loff_t offset, u64 ino, unsigned int d_type) { struct ecryptfs_getdents_callback *buf = - (struct ecryptfs_getdents_callback *)dirent; + container_of(ctx, struct ecryptfs_getdents_callback, ctx); size_t name_size; char *name; int rc; diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index a85ceb7c91bc..57ee4c53b4f8 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -641,7 +641,7 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry, } rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry, lower_new_dir_dentry->d_inode, lower_new_dentry, - NULL); + NULL, 0); if (rc) goto out_lock; if (target_inode) diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index 34eb8433d93f..d9eb84bda559 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -576,6 +576,13 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags s->s_maxbytes = path.dentry->d_sb->s_maxbytes; s->s_blocksize = path.dentry->d_sb->s_blocksize; s->s_magic = ECRYPTFS_SUPER_MAGIC; + s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1; + + rc = -EINVAL; + if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { + pr_err("eCryptfs: maximum fs stacking depth exceeded\n"); + goto out_free; + } inode = ecryptfs_get_inode(path.dentry->d_inode, s); rc = PTR_ERR(inode); diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index 831d4f057e15..aab21e5a545d 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -241,10 +241,11 @@ struct getdents_callback { * A rather strange filldir function to capture * the name matching the specified inode number. */ -static int filldir_one(void * __buf, const char * name, int len, +static int filldir_one(struct dir_context *ctx, const char *name, int len, loff_t pos, u64 ino, unsigned int d_type) { - struct getdents_callback *buf = __buf; + struct getdents_callback *buf = + container_of(ctx, struct getdents_callback, ctx); int result = 0; buf->sequence++; diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index bc7e37bc0c5b..8fb2db7deeb7 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -3193,6 +3193,16 @@ end_rename: return retval; } +static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) +{ + if (flags & ~RENAME_NOREPLACE) + return -EINVAL; + + return ext4_rename(old_dir, old_dentry, new_dir, new_dentry); +} + /* * directories can handle most operations... */ @@ -3206,7 +3216,7 @@ const struct inode_operations ext4_dir_inode_operations = { .rmdir = ext4_rmdir, .mknod = ext4_mknod, .tmpfile = ext4_tmpfile, - .rename = ext4_rename, + .rename2 = ext4_rename2, .setattr = ext4_setattr, .setxattr = generic_setxattr, .getxattr = generic_getxattr, diff --git a/fs/fat/dir.c b/fs/fat/dir.c index 3963ede84eb0..c5d6bb939d19 100644 --- a/fs/fat/dir.c +++ b/fs/fat/dir.c @@ -702,10 +702,11 @@ static int fat_readdir(struct file *file, struct dir_context *ctx) } #define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type) \ -static int func(void *__buf, const char *name, int name_len, \ +static int func(struct dir_context *ctx, const char *name, int name_len, \ loff_t offset, u64 ino, unsigned int d_type) \ { \ - struct fat_ioctl_filldir_callback *buf = __buf; \ + struct fat_ioctl_filldir_callback *buf = \ + container_of(ctx, struct fat_ioctl_filldir_callback, ctx); \ struct dirent_type __user *d1 = buf->dirent; \ struct dirent_type __user *d2 = d1 + 1; \ \ diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 342f0239fcbf..33dec83eccfb 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -680,6 +680,14 @@ static int fuse_symlink(struct inode *dir, struct dentry *entry, return create_new_entry(fc, req, dir, entry, S_IFLNK); } +static inline void fuse_update_ctime(struct inode *inode) +{ + if (!IS_NOCMTIME(inode)) { + inode->i_ctime = current_fs_time(inode->i_sb); + mark_inode_dirty_sync(inode); + } +} + static int fuse_unlink(struct inode *dir, struct dentry *entry) { int err; @@ -714,6 +722,7 @@ static int fuse_unlink(struct inode *dir, struct dentry *entry) fuse_invalidate_attr(inode); fuse_invalidate_attr(dir); fuse_invalidate_entry_cache(entry); + fuse_update_ctime(inode); } else if (err == -EINTR) fuse_invalidate_entry(entry); return err; @@ -744,23 +753,26 @@ static int fuse_rmdir(struct inode *dir, struct dentry *entry) return err; } -static int fuse_rename(struct inode *olddir, struct dentry *oldent, - struct inode *newdir, struct dentry *newent) +static int fuse_rename_common(struct inode *olddir, struct dentry *oldent, + struct inode *newdir, struct dentry *newent, + unsigned int flags, int opcode, size_t argsize) { int err; - struct fuse_rename_in inarg; + struct fuse_rename2_in inarg; struct fuse_conn *fc = get_fuse_conn(olddir); - struct fuse_req *req = fuse_get_req_nopages(fc); + struct fuse_req *req; + req = fuse_get_req_nopages(fc); if (IS_ERR(req)) return PTR_ERR(req); - memset(&inarg, 0, sizeof(inarg)); + memset(&inarg, 0, argsize); inarg.newdir = get_node_id(newdir); - req->in.h.opcode = FUSE_RENAME; + inarg.flags = flags; + req->in.h.opcode = opcode; req->in.h.nodeid = get_node_id(olddir); req->in.numargs = 3; - req->in.args[0].size = sizeof(inarg); + req->in.args[0].size = argsize; req->in.args[0].value = &inarg; req->in.args[1].size = oldent->d_name.len + 1; req->in.args[1].value = oldent->d_name.name; @@ -772,15 +784,22 @@ static int fuse_rename(struct inode *olddir, struct dentry *oldent, if (!err) { /* ctime changes */ fuse_invalidate_attr(oldent->d_inode); + fuse_update_ctime(oldent->d_inode); + + if (flags & RENAME_EXCHANGE) { + fuse_invalidate_attr(newent->d_inode); + fuse_update_ctime(newent->d_inode); + } fuse_invalidate_attr(olddir); if (olddir != newdir) fuse_invalidate_attr(newdir); /* newent will end up negative */ - if (newent->d_inode) { + if (!(flags & RENAME_EXCHANGE) && newent->d_inode) { fuse_invalidate_attr(newent->d_inode); fuse_invalidate_entry_cache(newent); + fuse_update_ctime(newent->d_inode); } } else if (err == -EINTR) { /* If request was interrupted, DEITY only knows if the @@ -796,6 +815,36 @@ static int fuse_rename(struct inode *olddir, struct dentry *oldent, return err; } +static int fuse_rename2(struct inode *olddir, struct dentry *oldent, + struct inode *newdir, struct dentry *newent, + unsigned int flags) +{ + struct fuse_conn *fc = get_fuse_conn(olddir); + int err; + + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) + return -EINVAL; + + if (flags) { + if (fc->no_rename2 || fc->minor < 23) + return -EINVAL; + + err = fuse_rename_common(olddir, oldent, newdir, newent, flags, + FUSE_RENAME2, + sizeof(struct fuse_rename2_in)); + if (err == -ENOSYS) { + fc->no_rename2 = 1; + err = -EINVAL; + } + } else { + err = fuse_rename_common(olddir, oldent, newdir, newent, 0, + FUSE_RENAME, + sizeof(struct fuse_rename_in)); + } + + return err; +} + static int fuse_link(struct dentry *entry, struct inode *newdir, struct dentry *newent) { @@ -830,6 +879,7 @@ static int fuse_link(struct dentry *entry, struct inode *newdir, inc_nlink(inode); spin_unlock(&fc->lock); fuse_invalidate_attr(inode); + fuse_update_ctime(inode); } else if (err == -EINTR) { fuse_invalidate_attr(inode); } @@ -840,6 +890,16 @@ static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr, struct kstat *stat) { unsigned int blkbits; + struct fuse_conn *fc = get_fuse_conn(inode); + + /* see the comment in fuse_change_attributes() */ + if (fc->writeback_cache && S_ISREG(inode->i_mode)) { + attr->size = i_size_read(inode); + attr->mtime = inode->i_mtime.tv_sec; + attr->mtimensec = inode->i_mtime.tv_nsec; + attr->ctime = inode->i_ctime.tv_sec; + attr->ctimensec = inode->i_ctime.tv_nsec; + } stat->dev = inode->i_sb->s_dev; stat->ino = attr->ino; @@ -1478,12 +1538,16 @@ static long fuse_dir_compat_ioctl(struct file *file, unsigned int cmd, FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR); } -static bool update_mtime(unsigned ivalid) +static bool update_mtime(unsigned ivalid, bool trust_local_mtime) { /* Always update if mtime is explicitly set */ if (ivalid & ATTR_MTIME_SET) return true; + /* Or if kernel i_mtime is the official one */ + if (trust_local_mtime) + return true; + /* If it's an open(O_TRUNC) or an ftruncate(), don't update */ if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE))) return false; @@ -1492,7 +1556,8 @@ static bool update_mtime(unsigned ivalid) return true; } -static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg) +static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg, + bool trust_local_mtime) { unsigned ivalid = iattr->ia_valid; @@ -1511,11 +1576,11 @@ static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg) if (!(ivalid & ATTR_ATIME_SET)) arg->valid |= FATTR_ATIME_NOW; } - if ((ivalid & ATTR_MTIME) && update_mtime(ivalid)) { + if ((ivalid & ATTR_MTIME) && update_mtime(ivalid, trust_local_mtime)) { arg->valid |= FATTR_MTIME; arg->mtime = iattr->ia_mtime.tv_sec; arg->mtimensec = iattr->ia_mtime.tv_nsec; - if (!(ivalid & ATTR_MTIME_SET)) + if (!(ivalid & ATTR_MTIME_SET) && !trust_local_mtime) arg->valid |= FATTR_MTIME_NOW; } } @@ -1564,6 +1629,63 @@ void fuse_release_nowrite(struct inode *inode) spin_unlock(&fc->lock); } +static void fuse_setattr_fill(struct fuse_conn *fc, struct fuse_req *req, + struct inode *inode, + struct fuse_setattr_in *inarg_p, + struct fuse_attr_out *outarg_p) +{ + req->in.h.opcode = FUSE_SETATTR; + req->in.h.nodeid = get_node_id(inode); + req->in.numargs = 1; + req->in.args[0].size = sizeof(*inarg_p); + req->in.args[0].value = inarg_p; + req->out.numargs = 1; + if (fc->minor < 9) + req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; + else + req->out.args[0].size = sizeof(*outarg_p); + req->out.args[0].value = outarg_p; +} + +/* + * Flush inode->i_mtime to the server + */ +int fuse_flush_mtime(struct file *file, bool nofail) +{ + struct inode *inode = file->f_mapping->host; + struct fuse_inode *fi = get_fuse_inode(inode); + struct fuse_conn *fc = get_fuse_conn(inode); + struct fuse_req *req = NULL; + struct fuse_setattr_in inarg; + struct fuse_attr_out outarg; + int err; + + if (nofail) { + req = fuse_get_req_nofail_nopages(fc, file); + } else { + req = fuse_get_req_nopages(fc); + if (IS_ERR(req)) + return PTR_ERR(req); + } + + memset(&inarg, 0, sizeof(inarg)); + memset(&outarg, 0, sizeof(outarg)); + + inarg.valid |= FATTR_MTIME; + inarg.mtime = inode->i_mtime.tv_sec; + inarg.mtimensec = inode->i_mtime.tv_nsec; + + fuse_setattr_fill(fc, req, inode, &inarg, &outarg); + fuse_request_send(fc, req); + err = req->out.h.error; + fuse_put_request(fc, req); + + if (!err) + clear_bit(FUSE_I_MTIME_DIRTY, &fi->state); + + return err; +} + /* * Set attributes, and at the same time refresh them. * @@ -1581,8 +1703,10 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr, struct fuse_setattr_in inarg; struct fuse_attr_out outarg; bool is_truncate = false; + bool is_wb = fc->writeback_cache; loff_t oldsize; int err; + bool trust_local_mtime = is_wb && S_ISREG(inode->i_mode); if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS)) attr->ia_valid |= ATTR_FORCE; @@ -1611,7 +1735,7 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr, memset(&inarg, 0, sizeof(inarg)); memset(&outarg, 0, sizeof(outarg)); - iattr_to_fattr(attr, &inarg); + iattr_to_fattr(attr, &inarg, trust_local_mtime); if (file) { struct fuse_file *ff = file->private_data; inarg.valid |= FATTR_FH; @@ -1622,17 +1746,7 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr, inarg.valid |= FATTR_LOCKOWNER; inarg.lock_owner = fuse_lock_owner_id(fc, current->files); } - req->in.h.opcode = FUSE_SETATTR; - req->in.h.nodeid = get_node_id(inode); - req->in.numargs = 1; - req->in.args[0].size = sizeof(inarg); - req->in.args[0].value = &inarg; - req->out.numargs = 1; - if (fc->minor < 9) - req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; - else - req->out.args[0].size = sizeof(outarg); - req->out.args[0].value = &outarg; + fuse_setattr_fill(fc, req, inode, &inarg, &outarg); fuse_request_send(fc, req); err = req->out.h.error; fuse_put_request(fc, req); @@ -1649,10 +1763,18 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr, } spin_lock(&fc->lock); + /* the kernel maintains i_mtime locally */ + if (trust_local_mtime && (attr->ia_valid & ATTR_MTIME)) { + inode->i_mtime = attr->ia_mtime; + clear_bit(FUSE_I_MTIME_DIRTY, &fi->state); + } + fuse_change_attributes_common(inode, &outarg.attr, attr_timeout(&outarg)); oldsize = inode->i_size; - i_size_write(inode, outarg.attr.size); + /* see the comment in fuse_change_attributes() */ + if (!is_wb || is_truncate || !S_ISREG(inode->i_mode)) + i_size_write(inode, outarg.attr.size); if (is_truncate) { /* NOTE: this may release/reacquire fc->lock */ @@ -1664,7 +1786,8 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr, * Only call invalidate_inode_pages2() after removing * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock. */ - if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) { + if ((is_truncate || !is_wb) && + S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) { truncate_pagecache(inode, outarg.attr.size); invalidate_inode_pages2(inode->i_mapping); } @@ -1740,8 +1863,10 @@ static int fuse_setxattr(struct dentry *entry, const char *name, fc->no_setxattr = 1; err = -EOPNOTSUPP; } - if (!err) + if (!err) { fuse_invalidate_attr(inode); + fuse_update_ctime(inode); + } return err; } @@ -1871,18 +1996,31 @@ static int fuse_removexattr(struct dentry *entry, const char *name) fc->no_removexattr = 1; err = -EOPNOTSUPP; } - if (!err) + if (!err) { fuse_invalidate_attr(inode); + fuse_update_ctime(inode); + } return err; } +static int fuse_update_time(struct inode *inode, struct timespec *now, + int flags) +{ + if (flags & S_MTIME) { + inode->i_mtime = *now; + set_bit(FUSE_I_MTIME_DIRTY, &get_fuse_inode(inode)->state); + BUG_ON(!S_ISREG(inode->i_mode)); + } + return 0; +} + static const struct inode_operations fuse_dir_inode_operations = { .lookup = fuse_lookup, .mkdir = fuse_mkdir, .symlink = fuse_symlink, .unlink = fuse_unlink, .rmdir = fuse_rmdir, - .rename = fuse_rename, + .rename2 = fuse_rename2, .link = fuse_link, .setattr = fuse_setattr, .create = fuse_create, @@ -1915,6 +2053,7 @@ static const struct inode_operations fuse_common_inode_operations = { .getxattr = fuse_getxattr, .listxattr = fuse_listxattr, .removexattr = fuse_removexattr, + .update_time = fuse_update_time, }; static const struct inode_operations fuse_symlink_inode_operations = { diff --git a/fs/fuse/file.c b/fs/fuse/file.c index d8a60270581c..5916dc51599b 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -188,6 +188,22 @@ int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file, } EXPORT_SYMBOL_GPL(fuse_do_open); +static void fuse_link_write_file(struct file *file) +{ + struct inode *inode = file_inode(file); + struct fuse_conn *fc = get_fuse_conn(inode); + struct fuse_inode *fi = get_fuse_inode(inode); + struct fuse_file *ff = file->private_data; + /* + * file may be written through mmap, so chain it onto the + * inodes's write_file list + */ + spin_lock(&fc->lock); + if (list_empty(&ff->write_entry)) + list_add(&ff->write_entry, &fi->write_files); + spin_unlock(&fc->lock); +} + void fuse_finish_open(struct inode *inode, struct file *file) { struct fuse_file *ff = file->private_data; @@ -292,6 +308,9 @@ static int fuse_open(struct inode *inode, struct file *file) static int fuse_release(struct inode *inode, struct file *file) { + if (test_bit(FUSE_I_MTIME_DIRTY, &get_fuse_inode(inode)->state)) + fuse_flush_mtime(file, true); + fuse_release_common(file, FUSE_RELEASE); /* return value is ignored by VFS */ @@ -459,6 +478,12 @@ int fuse_fsync_common(struct file *file, loff_t start, loff_t end, fuse_sync_writes(inode); + if (test_bit(FUSE_I_MTIME_DIRTY, &get_fuse_inode(inode)->state)) { + int err = fuse_flush_mtime(file, false); + if (err) + goto out; + } + req = fuse_get_req_nopages(fc); if (IS_ERR(req)) { err = PTR_ERR(req); @@ -655,6 +680,32 @@ static void fuse_read_update_size(struct inode *inode, loff_t size, spin_unlock(&fc->lock); } +static void fuse_short_read(struct fuse_req *req, struct inode *inode, + u64 attr_ver) +{ + size_t num_read = req->out.args[0].size; + struct fuse_conn *fc = get_fuse_conn(inode); + + if (fc->writeback_cache) { + /* + * A hole in a file. Some data after the hole are in page cache, + * but have not reached the client fs yet. So, the hole is not + * present there. + */ + int i; + int start_idx = num_read >> PAGE_CACHE_SHIFT; + size_t off = num_read & (PAGE_CACHE_SIZE - 1); + + for (i = start_idx; i < req->num_pages; i++) { + zero_user_segment(req->pages[i], off, PAGE_CACHE_SIZE); + off = 0; + } + } else { + loff_t pos = page_offset(req->pages[0]) + num_read; + fuse_read_update_size(inode, pos, attr_ver); + } +} + static int fuse_readpage(struct file *file, struct page *page) { struct fuse_io_priv io = { .async = 0, .file = file }; @@ -692,18 +743,18 @@ static int fuse_readpage(struct file *file, struct page *page) req->page_descs[0].length = count; num_read = fuse_send_read(req, &io, pos, count, NULL); err = req->out.h.error; - fuse_put_request(fc, req); if (!err) { /* * Short read means EOF. If file size is larger, truncate it */ if (num_read < count) - fuse_read_update_size(inode, pos + num_read, attr_ver); + fuse_short_read(req, inode, attr_ver); SetPageUptodate(page); } + fuse_put_request(fc, req); fuse_invalidate_atime(inode); out: unlock_page(page); @@ -726,13 +777,9 @@ static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req) /* * Short read means EOF. If file size is larger, truncate it */ - if (!req->out.h.error && num_read < count) { - loff_t pos; + if (!req->out.h.error && num_read < count) + fuse_short_read(req, inode, req->misc.read.attr_ver); - pos = page_offset(req->pages[0]) + num_read; - fuse_read_update_size(inode, pos, - req->misc.read.attr_ver); - } fuse_invalidate_atime(inode); } @@ -922,16 +969,21 @@ static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io, return req->misc.write.out.size; } -void fuse_write_update_size(struct inode *inode, loff_t pos) +bool fuse_write_update_size(struct inode *inode, loff_t pos) { struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_inode *fi = get_fuse_inode(inode); + bool ret = false; spin_lock(&fc->lock); fi->attr_version = ++fc->attr_version; - if (pos > inode->i_size) + if (pos > inode->i_size) { i_size_write(inode, pos); + ret = true; + } spin_unlock(&fc->lock); + + return ret; } static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file, @@ -1942,20 +1994,9 @@ static const struct vm_operations_struct fuse_file_vm_ops = { static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma) { - if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) { - struct inode *inode = file_inode(file); - struct fuse_conn *fc = get_fuse_conn(inode); - struct fuse_inode *fi = get_fuse_inode(inode); - struct fuse_file *ff = file->private_data; - /* - * file may be written through mmap, so chain it onto the - * inodes's write_file list - */ - spin_lock(&fc->lock); - if (list_empty(&ff->write_entry)) - list_add(&ff->write_entry, &fi->write_files); - spin_unlock(&fc->lock); - } + if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) + fuse_link_write_file(file); + file_accessed(file); vma->vm_ops = &fuse_file_vm_ops; return 0; @@ -2846,8 +2887,16 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset, goto out; /* we could have extended the file */ - if (!(mode & FALLOC_FL_KEEP_SIZE)) - fuse_write_update_size(inode, offset + length); + if (!(mode & FALLOC_FL_KEEP_SIZE)) { + bool changed = fuse_write_update_size(inode, offset + length); + + if (changed && fc->writeback_cache) { + struct fuse_inode *fi = get_fuse_inode(inode); + + inode->i_mtime = current_fs_time(inode->i_sb); + set_bit(FUSE_I_MTIME_DIRTY, &fi->state); + } + } if (mode & FALLOC_FL_PUNCH_HOLE) truncate_pagecache_range(inode, offset, offset + length - 1); diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 2da5db2c8bdb..7cc58c976780 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -119,6 +119,8 @@ enum { FUSE_I_INIT_RDPLUS, /** An operation changing file size is in progress */ FUSE_I_SIZE_UNSTABLE, + /** i_mtime has been updated locally; a flush to userspace needed */ + FUSE_I_MTIME_DIRTY, }; struct fuse_conn; @@ -480,6 +482,9 @@ struct fuse_conn { /** Set if bdi is valid */ unsigned bdi_initialized:1; + /** write-back cache policy (default is write-through) */ + unsigned writeback_cache:1; + /* * The following bitfields are only for optimization purposes * and hence races in setting them will not cause malfunction @@ -539,6 +544,9 @@ struct fuse_conn { /** Is fallocate not implemented by fs? */ unsigned no_fallocate:1; + /** Is rename with flags implemented by fs? */ + unsigned no_rename2:1; + /** Use enhanced/automatic page cache invalidation. */ unsigned auto_inval_data:1; @@ -873,7 +881,9 @@ long fuse_ioctl_common(struct file *file, unsigned int cmd, unsigned fuse_file_poll(struct file *file, poll_table *wait); int fuse_dev_release(struct inode *inode, struct file *file); -void fuse_write_update_size(struct inode *inode, loff_t pos); +bool fuse_write_update_size(struct inode *inode, loff_t pos); + +int fuse_flush_mtime(struct file *file, bool nofail); int fuse_do_setattr(struct inode *inode, struct iattr *attr, struct file *file); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 73f6bcb44ea8..8fe0b485908c 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -170,10 +170,13 @@ void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr, inode->i_blocks = attr->blocks; inode->i_atime.tv_sec = attr->atime; inode->i_atime.tv_nsec = attr->atimensec; - inode->i_mtime.tv_sec = attr->mtime; - inode->i_mtime.tv_nsec = attr->mtimensec; - inode->i_ctime.tv_sec = attr->ctime; - inode->i_ctime.tv_nsec = attr->ctimensec; + /* mtime from server may be stale due to local buffered write */ + if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) { + inode->i_mtime.tv_sec = attr->mtime; + inode->i_mtime.tv_nsec = attr->mtimensec; + inode->i_ctime.tv_sec = attr->ctime; + inode->i_ctime.tv_nsec = attr->ctimensec; + } if (attr->blksize != 0) inode->i_blkbits = ilog2(attr->blksize); @@ -197,6 +200,7 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, { struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_inode *fi = get_fuse_inode(inode); + bool is_wb = fc->writeback_cache; loff_t oldsize; struct timespec old_mtime; @@ -211,10 +215,16 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, fuse_change_attributes_common(inode, attr, attr_valid); oldsize = inode->i_size; - i_size_write(inode, attr->size); + /* + * In case of writeback_cache enabled, the cached writes beyond EOF + * extend local i_size without keeping userspace server in sync. So, + * attr->size coming from server can be stale. We cannot trust it. + */ + if (!is_wb || !S_ISREG(inode->i_mode)) + i_size_write(inode, attr->size); spin_unlock(&fc->lock); - if (S_ISREG(inode->i_mode)) { + if (!is_wb && S_ISREG(inode->i_mode)) { bool inval = false; if (oldsize != attr->size) { @@ -243,6 +253,10 @@ static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr) { inode->i_mode = attr->mode & S_IFMT; inode->i_size = attr->size; + inode->i_mtime.tv_sec = attr->mtime; + inode->i_mtime.tv_nsec = attr->mtimensec; + inode->i_ctime.tv_sec = attr->ctime; + inode->i_ctime.tv_nsec = attr->ctimensec; if (S_ISREG(inode->i_mode)) { fuse_init_common(inode); fuse_init_file_inode(inode); @@ -289,7 +303,9 @@ struct inode *fuse_iget(struct super_block *sb, u64 nodeid, return NULL; if ((inode->i_state & I_NEW)) { - inode->i_flags |= S_NOATIME|S_NOCMTIME; + inode->i_flags |= S_NOATIME; + if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) + inode->i_flags |= S_NOCMTIME; inode->i_generation = generation; inode->i_data.backing_dev_info = &fc->bdi; fuse_init_inode(inode, attr); diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c index 8b9b3775e2e7..c41d255b6a7b 100644 --- a/fs/gfs2/export.c +++ b/fs/gfs2/export.c @@ -69,10 +69,12 @@ struct get_name_filldir { char *name; }; -static int get_name_filldir(void *opaque, const char *name, int length, - loff_t offset, u64 inum, unsigned int type) +static int get_name_filldir(struct dir_context *ctx, const char *name, + int length, loff_t offset, u64 inum, + unsigned int type) { - struct get_name_filldir *gnfd = opaque; + struct get_name_filldir *gnfd = + container_of(ctx, struct get_name_filldir, ctx); if (inum != gnfd->inum.no_addr) return 0; diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c index 4338ff32959d..5f2755117ce7 100644 --- a/fs/hppfs/hppfs.c +++ b/fs/hppfs/hppfs.c @@ -548,10 +548,11 @@ struct hppfs_dirent { struct dentry *dentry; }; -static int hppfs_filldir(void *d, const char *name, int size, +static int hppfs_filldir(struct dir_context *ctx, const char *name, int size, loff_t offset, u64 inode, unsigned int type) { - struct hppfs_dirent *dirent = d; + struct hppfs_dirent *dirent = + container_of(ctx, struct hppfs_dirent, ctx); if (file_removed(dirent->dentry, name)) return 0; diff --git a/fs/internal.h b/fs/internal.h index 465742407466..dd41b12c13f1 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -42,7 +42,6 @@ extern void __init chrdev_init(void); /* * namei.c */ -extern int __inode_permission(struct inode *, int); extern int user_path_mountpoint_at(int, const char __user *, unsigned int, struct path *); extern int vfs_path_lookup(struct dentry *, struct vfsmount *, const char *, unsigned int, struct path *); @@ -135,12 +134,6 @@ extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *); extern int rw_verify_area(int, struct file *, const loff_t *, size_t); /* - * splice.c - */ -extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, - loff_t *opos, size_t len, unsigned int flags); - -/* * pipe.c */ extern const struct file_operations pipefifo_fops; diff --git a/fs/namei.c b/fs/namei.c index ccb8000f3459..7ee6af0672b2 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -415,6 +415,7 @@ int __inode_permission(struct inode *inode, int mask) return security_inode_permission(inode, mask); } +EXPORT_SYMBOL(__inode_permission); /** * sb_permission - Check superblock-level permissions @@ -2360,22 +2361,17 @@ kern_path_mountpoint(int dfd, const char *name, struct path *path, } EXPORT_SYMBOL(kern_path_mountpoint); -/* - * It's inline, so penalty for filesystems that don't use sticky bit is - * minimal. - */ -static inline int check_sticky(struct inode *dir, struct inode *inode) +int __check_sticky(struct inode *dir, struct inode *inode) { kuid_t fsuid = current_fsuid(); - if (!(dir->i_mode & S_ISVTX)) - return 0; if (uid_eq(inode->i_uid, fsuid)) return 0; if (uid_eq(dir->i_uid, fsuid)) return 0; return !capable_wrt_inode_uidgid(inode, CAP_FOWNER); } +EXPORT_SYMBOL(__check_sticky); /* * Check whether we can remove a link victim from directory dir, check @@ -2478,7 +2474,7 @@ struct dentry *lock_rename(struct dentry *p1, struct dentry *p2) } mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD); + mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT2); return NULL; } @@ -3039,9 +3035,12 @@ finish_open_created: error = may_open(&nd->path, acc_mode, open_flag); if (error) goto out; - file->f_path.mnt = nd->path.mnt; - error = finish_open(file, nd->path.dentry, NULL, opened); - if (error) { + + BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */ + error = vfs_open(&nd->path, file, current_cred()); + if (!error) { + *opened |= FILE_OPENED; + } else { if (error == -EOPENSTALE) goto stale_open; goto out; @@ -3979,7 +3978,28 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); } -/* +/** + * vfs_rename - rename a filesystem object + * @old_dir: parent of source + * @old_dentry: source + * @new_dir: parent of destination + * @new_dentry: destination + * @delegated_inode: returns an inode needing a delegation break + * @flags: rename flags + * + * The caller must hold multiple mutexes--see lock_rename()). + * + * If vfs_rename discovers a delegation in need of breaking at either + * the source or destination, it will return -EWOULDBLOCK and return a + * reference to the inode in delegated_inode. The caller should then + * break the delegation and retry. Because breaking a delegation may + * take a long time, the caller should drop all locks before doing + * so. + * + * Alternatively, a caller may pass NULL for delegated_inode. This may + * be appropriate for callers that expect the underlying filesystem not + * to be NFS exported. + * * The worst of all namespace operations - renaming directory. "Perverted" * doesn't even start to describe it. Somebody in UCB had a heck of a trip... * Problems: @@ -4007,163 +4027,140 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname * ->i_mutex on parents, which works but leads to some truly excessive * locking]. */ -static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry) +int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + struct inode **delegated_inode, unsigned int flags) { - int error = 0; + int error; + bool is_dir = d_is_dir(old_dentry); + const unsigned char *old_name; + struct inode *source = old_dentry->d_inode; struct inode *target = new_dentry->d_inode; + bool new_is_dir = false; unsigned max_links = new_dir->i_sb->s_max_links; + if (source == target) + return 0; + + error = may_delete(old_dir, old_dentry, is_dir); + if (error) + return error; + + if (!target) { + error = may_create(new_dir, new_dentry); + } else { + new_is_dir = d_is_dir(new_dentry); + + if (!(flags & RENAME_EXCHANGE)) + error = may_delete(new_dir, new_dentry, is_dir); + else + error = may_delete(new_dir, new_dentry, new_is_dir); + } + if (error) + return error; + + if (!old_dir->i_op->rename && !old_dir->i_op->rename2) + return -EPERM; + + if (flags && !old_dir->i_op->rename2) + return -EINVAL; + /* * If we are going to change the parent - check write permissions, * we'll need to flip '..'. */ if (new_dir != old_dir) { - error = inode_permission(old_dentry->d_inode, MAY_WRITE); - if (error) - return error; + if (is_dir) { + error = inode_permission(source, MAY_WRITE); + if (error) + return error; + } + if ((flags & RENAME_EXCHANGE) && new_is_dir) { + error = inode_permission(target, MAY_WRITE); + if (error) + return error; + } } - error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry); + error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry, + flags); if (error) return error; + old_name = fsnotify_oldname_init(old_dentry->d_name.name); dget(new_dentry); - if (target) + if (!is_dir || (flags & RENAME_EXCHANGE)) + lock_two_nondirectories(source, target); + else if (target) mutex_lock(&target->i_mutex); error = -EBUSY; if (d_mountpoint(old_dentry) || d_mountpoint(new_dentry)) goto out; - error = -EMLINK; - if (max_links && !target && new_dir != old_dir && - new_dir->i_nlink >= max_links) - goto out; - - if (target) + if (max_links && new_dir != old_dir) { + error = -EMLINK; + if (is_dir && !new_is_dir && new_dir->i_nlink >= max_links) + goto out; + if ((flags & RENAME_EXCHANGE) && !is_dir && new_is_dir && + old_dir->i_nlink >= max_links) + goto out; + } + if (is_dir && !(flags & RENAME_EXCHANGE) && target) shrink_dcache_parent(new_dentry); - error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); - if (error) - goto out; - - if (target) { - target->i_flags |= S_DEAD; - dont_mount(new_dentry); + if (!is_dir) { + error = try_break_deleg(source, delegated_inode); + if (error) + goto out; } -out: - if (target) - mutex_unlock(&target->i_mutex); - dput(new_dentry); - if (!error) - if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) - d_move(old_dentry,new_dentry); - return error; -} - -static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry, - struct inode **delegated_inode) -{ - struct inode *target = new_dentry->d_inode; - struct inode *source = old_dentry->d_inode; - int error; - - error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry); - if (error) - return error; - - dget(new_dentry); - lock_two_nondirectories(source, target); - - error = -EBUSY; - if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry)) - goto out; - - error = try_break_deleg(source, delegated_inode); - if (error) - goto out; - if (target) { + if (target && !new_is_dir) { error = try_break_deleg(target, delegated_inode); if (error) goto out; } - error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); + if (!old_dir->i_op->rename2) { + error = old_dir->i_op->rename(old_dir, old_dentry, + new_dir, new_dentry); + } else { + WARN_ON(old_dir->i_op->rename != NULL); + error = old_dir->i_op->rename2(old_dir, old_dentry, + new_dir, new_dentry, flags); + } if (error) goto out; - if (target) + if (!(flags & RENAME_EXCHANGE) && target) { + if (is_dir) + target->i_flags |= S_DEAD; dont_mount(new_dentry); - if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) - d_move(old_dentry, new_dentry); + } + if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) { + if (!(flags & RENAME_EXCHANGE)) + d_move(old_dentry, new_dentry); + else + d_exchange(old_dentry, new_dentry); + } out: - unlock_two_nondirectories(source, target); + if (!is_dir || (flags & RENAME_EXCHANGE)) + unlock_two_nondirectories(source, target); + else if (target) + mutex_unlock(&target->i_mutex); dput(new_dentry); - return error; -} - -/** - * vfs_rename - rename a filesystem object - * @old_dir: parent of source - * @old_dentry: source - * @new_dir: parent of destination - * @new_dentry: destination - * @delegated_inode: returns an inode needing a delegation break - * - * The caller must hold multiple mutexes--see lock_rename()). - * - * If vfs_rename discovers a delegation in need of breaking at either - * the source or destination, it will return -EWOULDBLOCK and return a - * reference to the inode in delegated_inode. The caller should then - * break the delegation and retry. Because breaking a delegation may - * take a long time, the caller should drop all locks before doing - * so. - * - * Alternatively, a caller may pass NULL for delegated_inode. This may - * be appropriate for callers that expect the underlying filesystem not - * to be NFS exported. - */ -int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry, - struct inode **delegated_inode) -{ - int error; - int is_dir = d_is_dir(old_dentry); - const unsigned char *old_name; - - if (old_dentry->d_inode == new_dentry->d_inode) - return 0; - - error = may_delete(old_dir, old_dentry, is_dir); - if (error) - return error; - - if (!new_dentry->d_inode) - error = may_create(new_dir, new_dentry); - else - error = may_delete(new_dir, new_dentry, is_dir); - if (error) - return error; - - if (!old_dir->i_op->rename) - return -EPERM; - - old_name = fsnotify_oldname_init(old_dentry->d_name.name); - - if (is_dir) - error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry); - else - error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry,delegated_inode); - if (!error) + if (!error) { fsnotify_move(old_dir, new_dir, old_name, is_dir, - new_dentry->d_inode, old_dentry); + !(flags & RENAME_EXCHANGE) ? target : NULL, old_dentry); + if (flags & RENAME_EXCHANGE) { + fsnotify_move(new_dir, old_dir, old_dentry->d_name.name, + new_is_dir, NULL, new_dentry); + } + } fsnotify_oldname_free(old_name); return error; } -SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, - int, newdfd, const char __user *, newname) +SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname, + int, newdfd, const char __user *, newname, unsigned int, flags) { struct dentry *old_dir, *new_dir; struct dentry *old_dentry, *new_dentry; @@ -4175,6 +4172,17 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, unsigned int lookup_flags = 0; bool should_retry = false; int error; + + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) + return -EINVAL; + + if ((flags & (RENAME_NOREPLACE | RENAME_WHITEOUT)) && + (flags & RENAME_EXCHANGE)) + return -EINVAL; + + if ((flags & RENAME_WHITEOUT) && !capable(CAP_MKNOD)) + return -EPERM; + retry: from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags); if (IS_ERR(from)) { @@ -4198,6 +4206,8 @@ retry: goto exit2; new_dir = newnd.path.dentry; + if (flags & RENAME_NOREPLACE) + error = -EEXIST; if (newnd.last_type != LAST_NORM) goto exit2; @@ -4207,7 +4217,8 @@ retry: oldnd.flags &= ~LOOKUP_PARENT; newnd.flags &= ~LOOKUP_PARENT; - newnd.flags |= LOOKUP_RENAME_TARGET; + if (!(flags & RENAME_EXCHANGE)) + newnd.flags |= LOOKUP_RENAME_TARGET; retry_deleg: trap = lock_rename(new_dir, old_dir); @@ -4220,34 +4231,49 @@ retry_deleg: error = -ENOENT; if (d_is_negative(old_dentry)) goto exit4; + new_dentry = lookup_hash(&newnd); + error = PTR_ERR(new_dentry); + if (IS_ERR(new_dentry)) + goto exit4; + error = -EEXIST; + if ((flags & RENAME_NOREPLACE) && d_is_positive(new_dentry)) + goto exit5; + if (flags & RENAME_EXCHANGE) { + error = -ENOENT; + if (d_is_negative(new_dentry)) + goto exit5; + + if (!d_is_dir(new_dentry)) { + error = -ENOTDIR; + if (newnd.last.name[newnd.last.len]) + goto exit5; + } + } /* unless the source is a directory trailing slashes give -ENOTDIR */ if (!d_is_dir(old_dentry)) { error = -ENOTDIR; if (oldnd.last.name[oldnd.last.len]) - goto exit4; - if (newnd.last.name[newnd.last.len]) - goto exit4; + goto exit5; + if (!(flags & RENAME_EXCHANGE) && newnd.last.name[newnd.last.len]) + goto exit5; } /* source should not be ancestor of target */ error = -EINVAL; if (old_dentry == trap) - goto exit4; - new_dentry = lookup_hash(&newnd); - error = PTR_ERR(new_dentry); - if (IS_ERR(new_dentry)) - goto exit4; + goto exit5; /* target should not be an ancestor of source */ - error = -ENOTEMPTY; + if (!(flags & RENAME_EXCHANGE)) + error = -ENOTEMPTY; if (new_dentry == trap) goto exit5; error = security_path_rename(&oldnd.path, old_dentry, - &newnd.path, new_dentry); + &newnd.path, new_dentry, flags); if (error) goto exit5; error = vfs_rename(old_dir->d_inode, old_dentry, - new_dir->d_inode, new_dentry, - &delegated_inode); + new_dir->d_inode, new_dentry, + &delegated_inode, flags); exit5: dput(new_dentry); exit4: @@ -4277,16 +4303,34 @@ exit: return error; } +SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, + int, newdfd, const char __user *, newname) +{ + return sys_renameat2(olddfd, oldname, newdfd, newname, 0); +} + SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newname) { - return sys_renameat(AT_FDCWD, oldname, AT_FDCWD, newname); + return sys_renameat2(AT_FDCWD, oldname, AT_FDCWD, newname, 0); } -int vfs_readlink(struct dentry *dentry, char __user *buffer, int buflen, const char *link) +int vfs_whiteout(struct inode *dir, struct dentry *dentry) { - int len; + int error = may_create(dir, dentry); + if (error) + return error; - len = PTR_ERR(link); + if (!dir->i_op->mknod) + return -EPERM; + + return dir->i_op->mknod(dir, dentry, + S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV); +} +EXPORT_SYMBOL(vfs_whiteout); + +int readlink_copy(char __user *buffer, int buflen, const char *link) +{ + int len = PTR_ERR(link); if (IS_ERR(link)) goto out; @@ -4315,7 +4359,7 @@ int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen) if (IS_ERR(cookie)) return PTR_ERR(cookie); - res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd)); + res = readlink_copy(buffer, buflen, nd_get_link(&nd)); if (dentry->d_inode->i_op->put_link) dentry->d_inode->i_op->put_link(dentry, &nd, cookie); return res; @@ -4339,8 +4383,7 @@ static char *page_getlink(struct dentry * dentry, struct page **ppage) int page_readlink(struct dentry *dentry, char __user *buffer, int buflen) { struct page *page = NULL; - char *s = page_getlink(dentry, &page); - int res = vfs_readlink(dentry,buffer,buflen,s); + int res = readlink_copy(buffer, buflen, page_getlink(dentry, &page)); if (page) { kunmap(page); page_cache_release(page); @@ -4436,7 +4479,6 @@ EXPORT_SYMBOL(vfs_link); EXPORT_SYMBOL(vfs_mkdir); EXPORT_SYMBOL(vfs_mknod); EXPORT_SYMBOL(generic_permission); -EXPORT_SYMBOL(vfs_readlink); EXPORT_SYMBOL(vfs_rename); EXPORT_SYMBOL(vfs_rmdir); EXPORT_SYMBOL(vfs_symlink); diff --git a/fs/namespace.c b/fs/namespace.c index 039f3802d70e..c6533ce9cdee 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1586,6 +1586,33 @@ void drop_collected_mounts(struct vfsmount *mnt) namespace_unlock(); } +/** + * clone_private_mount - create a private clone of a path + * + * This creates a new vfsmount, which will be the clone of @path. The new will + * not be attached anywhere in the namespace and will be private (i.e. changes + * to the originating mount won't be propagated into this). + * + * Release with mntput(). + */ +struct vfsmount *clone_private_mount(struct path *path) +{ + struct mount *old_mnt = real_mount(path->mnt); + struct mount *new_mnt; + + if (IS_MNT_UNBINDABLE(old_mnt)) + return ERR_PTR(-EINVAL); + + down_read(&namespace_sem); + new_mnt = clone_mnt(old_mnt, path->dentry, CL_PRIVATE); + up_read(&namespace_sem); + if (IS_ERR(new_mnt)) + return ERR_CAST(new_mnt); + + return &new_mnt->mnt; +} +EXPORT_SYMBOL_GPL(clone_private_mount); + int iterate_mounts(int (*f)(struct vfsmount *, void *), void *arg, struct vfsmount *root) { diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index 9c271f42604a..674a5d529e09 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -244,10 +244,11 @@ struct nfs4_dir_ctx { }; static int -nfsd4_build_namelist(void *arg, const char *name, int namlen, +nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { - struct nfs4_dir_ctx *ctx = arg; + struct nfs4_dir_ctx *ctx = + container_of(__ctx, struct nfs4_dir_ctx, ctx); struct name_list *entry; if (namlen != HEXDIR_LEN - 1) diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index eea5ad188984..3953a20db16d 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1703,7 +1703,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry) goto out_dput_new; - host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL); + host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0); if (!host_err) { host_err = commit_metadata(tfhp); if (!host_err) @@ -1808,10 +1808,12 @@ struct readdir_data { int full; }; -static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen, - loff_t offset, u64 ino, unsigned int d_type) +static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name, + int namlen, loff_t offset, u64 ino, + unsigned int d_type) { - struct readdir_data *buf = __buf; + struct readdir_data *buf = + container_of(ctx, struct readdir_data, ctx); struct buffered_dirent *de = (void *)(buf->dirent + buf->used); unsigned int reclen; @@ -1831,7 +1833,7 @@ static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen, return 0; } -static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func, +static __be32 nfsd_buffered_readdir(struct file *file, nfsd_filldir_t func, struct readdir_cd *cdp, loff_t *offsetp) { struct buffered_dirent *de; @@ -1915,7 +1917,7 @@ static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func, */ __be32 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, - struct readdir_cd *cdp, filldir_t func) + struct readdir_cd *cdp, nfsd_filldir_t func) { __be32 err; struct file *file; diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h index fbe90bdb2214..ea760b17ecbd 100644 --- a/fs/nfsd/vfs.h +++ b/fs/nfsd/vfs.h @@ -36,7 +36,7 @@ /* * Callback function for readdir */ -typedef int (*nfsd_dirop_t)(struct inode *, struct dentry *, int, int); +typedef int (*nfsd_filldir_t)(void *, const char *, int, loff_t, u64, unsigned); /* nfsd/vfs.c */ int nfsd_racache_init(int); @@ -89,7 +89,7 @@ __be32 nfsd_rename(struct svc_rqst *, __be32 nfsd_unlink(struct svc_rqst *, struct svc_fh *, int type, char *name, int len); __be32 nfsd_readdir(struct svc_rqst *, struct svc_fh *, - loff_t *, struct readdir_cd *, filldir_t); + loff_t *, struct readdir_cd *, nfsd_filldir_t); __be32 nfsd_statfs(struct svc_rqst *, struct svc_fh *, struct kstatfs *, int access); diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c index 91a7e85ac8fd..478e14d7be54 100644 --- a/fs/ocfs2/dir.c +++ b/fs/ocfs2/dir.c @@ -2073,10 +2073,12 @@ struct ocfs2_empty_dir_priv { unsigned seen_other; unsigned dx_dir; }; -static int ocfs2_empty_dir_filldir(void *priv, const char *name, int name_len, - loff_t pos, u64 ino, unsigned type) +static int ocfs2_empty_dir_filldir(struct dir_context *ctx, const char *name, + int name_len, loff_t pos, u64 ino, + unsigned type) { - struct ocfs2_empty_dir_priv *p = priv; + struct ocfs2_empty_dir_priv *p = + container_of(ctx, struct ocfs2_empty_dir_priv, ctx); /* * Check the positions of "." and ".." records to be sure diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c index 44fc3e530c3d..a1b7dca075dd 100644 --- a/fs/ocfs2/journal.c +++ b/fs/ocfs2/journal.c @@ -1981,10 +1981,12 @@ struct ocfs2_orphan_filldir_priv { struct ocfs2_super *osb; }; -static int ocfs2_orphan_filldir(void *priv, const char *name, int name_len, - loff_t pos, u64 ino, unsigned type) +static int ocfs2_orphan_filldir(struct dir_context *ctx, const char *name, + int name_len, loff_t pos, u64 ino, + unsigned type) { - struct ocfs2_orphan_filldir_priv *p = priv; + struct ocfs2_orphan_filldir_priv *p = + container_of(ctx, struct ocfs2_orphan_filldir_priv, ctx); struct inode *iter; if (name_len == 1 && !strncmp(".", name, 1)) diff --git a/fs/open.c b/fs/open.c index 17679f2b2f1c..8d30711435d8 100644 --- a/fs/open.c +++ b/fs/open.c @@ -822,8 +822,7 @@ struct file *dentry_open(const struct path *path, int flags, f = get_empty_filp(); if (!IS_ERR(f)) { f->f_flags = flags; - f->f_path = *path; - error = do_dentry_open(f, NULL, cred); + error = vfs_open(path, f, cred); if (!error) { /* from now on we need fput() to dispose of f */ error = open_check_o_direct(f); @@ -840,6 +839,26 @@ struct file *dentry_open(const struct path *path, int flags, } EXPORT_SYMBOL(dentry_open); +/** + * vfs_open - open the file at the given path + * @path: path to open + * @filp: newly allocated file with f_flag initialized + * @cred: credentials to use + */ +int vfs_open(const struct path *path, struct file *filp, + const struct cred *cred) +{ + struct inode *inode = path->dentry->d_inode; + + if (inode->i_op->dentry_open) + return inode->i_op->dentry_open(path->dentry, filp, cred); + else { + filp->f_path = *path; + return do_dentry_open(filp, NULL, cred); + } +} +EXPORT_SYMBOL(vfs_open); + static inline int build_open_flags(int flags, umode_t mode, struct open_flags *op) { int lookup_flags = 0; diff --git a/fs/overlayfs/Kconfig b/fs/overlayfs/Kconfig new file mode 100644 index 000000000000..34355818a2e0 --- /dev/null +++ b/fs/overlayfs/Kconfig @@ -0,0 +1,10 @@ +config OVERLAY_FS + tristate "Overlay filesystem support" + help + An overlay filesystem combines two filesystems - an 'upper' filesystem + and a 'lower' filesystem. When a name exists in both filesystems, the + object in the 'upper' filesystem is visible while the object in the + 'lower' filesystem is either hidden or, in the case of directories, + merged with the 'upper' object. + + For more information see Documentation/filesystems/overlayfs.txt diff --git a/fs/overlayfs/Makefile b/fs/overlayfs/Makefile new file mode 100644 index 000000000000..900daed3e91d --- /dev/null +++ b/fs/overlayfs/Makefile @@ -0,0 +1,7 @@ +# +# Makefile for the overlay filesystem. +# + +obj-$(CONFIG_OVERLAY_FS) += overlay.o + +overlay-objs := super.o inode.o dir.o readdir.o copy_up.o diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c new file mode 100644 index 000000000000..24f640441bd9 --- /dev/null +++ b/fs/overlayfs/copy_up.c @@ -0,0 +1,413 @@ +/* + * + * Copyright (C) 2011 Novell Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/file.h> +#include <linux/splice.h> +#include <linux/xattr.h> +#include <linux/security.h> +#include <linux/uaccess.h> +#include <linux/sched.h> +#include <linux/namei.h> +#include "overlayfs.h" + +#define OVL_COPY_UP_CHUNK_SIZE (1 << 20) + +int ovl_copy_xattr(struct dentry *old, struct dentry *new) +{ + ssize_t list_size, size; + char *buf, *name, *value; + int error; + + if (!old->d_inode->i_op->getxattr || + !new->d_inode->i_op->getxattr) + return 0; + + list_size = vfs_listxattr(old, NULL, 0); + if (list_size <= 0) { + if (list_size == -EOPNOTSUPP) + return 0; + return list_size; + } + + buf = kzalloc(list_size, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + error = -ENOMEM; + value = kmalloc(XATTR_SIZE_MAX, GFP_KERNEL); + if (!value) + goto out; + + list_size = vfs_listxattr(old, buf, list_size); + if (list_size <= 0) { + error = list_size; + goto out_free_value; + } + + for (name = buf; name < (buf + list_size); name += strlen(name) + 1) { + size = vfs_getxattr(old, name, value, XATTR_SIZE_MAX); + if (size <= 0) { + error = size; + goto out_free_value; + } + error = vfs_setxattr(new, name, value, size, 0); + if (error) + goto out_free_value; + } + +out_free_value: + kfree(value); +out: + kfree(buf); + return error; +} + +static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) +{ + struct file *old_file; + struct file *new_file; + loff_t old_pos = 0; + loff_t new_pos = 0; + int error = 0; + + if (len == 0) + return 0; + + old_file = ovl_path_open(old, O_RDONLY); + if (IS_ERR(old_file)) + return PTR_ERR(old_file); + + new_file = ovl_path_open(new, O_WRONLY); + if (IS_ERR(new_file)) { + error = PTR_ERR(new_file); + goto out_fput; + } + + /* FIXME: copy up sparse files efficiently */ + while (len) { + size_t this_len = OVL_COPY_UP_CHUNK_SIZE; + long bytes; + + if (len < this_len) + this_len = len; + + if (signal_pending_state(TASK_KILLABLE, current)) { + error = -EINTR; + break; + } + + bytes = do_splice_direct(old_file, &old_pos, + new_file, &new_pos, + this_len, SPLICE_F_MOVE); + if (bytes <= 0) { + error = bytes; + break; + } + WARN_ON(old_pos != new_pos); + + len -= bytes; + } + + fput(new_file); +out_fput: + fput(old_file); + return error; +} + +static char *ovl_read_symlink(struct dentry *realdentry) +{ + int res; + char *buf; + struct inode *inode = realdentry->d_inode; + mm_segment_t old_fs; + + res = -EINVAL; + if (!inode->i_op->readlink) + goto err; + + res = -ENOMEM; + buf = (char *) __get_free_page(GFP_KERNEL); + if (!buf) + goto err; + + old_fs = get_fs(); + set_fs(get_ds()); + /* The cast to a user pointer is valid due to the set_fs() */ + res = inode->i_op->readlink(realdentry, + (char __user *)buf, PAGE_SIZE - 1); + set_fs(old_fs); + if (res < 0) { + free_page((unsigned long) buf); + goto err; + } + buf[res] = '\0'; + + return buf; + +err: + return ERR_PTR(res); +} + +static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat) +{ + struct iattr attr = { + .ia_valid = + ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET, + .ia_atime = stat->atime, + .ia_mtime = stat->mtime, + }; + + return notify_change(upperdentry, &attr, NULL); +} + +int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat) +{ + int err = 0; + + if (!S_ISLNK(stat->mode)) { + struct iattr attr = { + .ia_valid = ATTR_MODE, + .ia_mode = stat->mode, + }; + err = notify_change(upperdentry, &attr, NULL); + } + if (!err) { + struct iattr attr = { + .ia_valid = ATTR_UID | ATTR_GID, + .ia_uid = stat->uid, + .ia_gid = stat->gid, + }; + err = notify_change(upperdentry, &attr, NULL); + } + if (!err) + ovl_set_timestamps(upperdentry, stat); + + return err; +} + +static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, + struct dentry *dentry, struct path *lowerpath, + struct kstat *stat, struct iattr *attr, + const char *link) +{ + struct inode *wdir = workdir->d_inode; + struct inode *udir = upperdir->d_inode; + struct dentry *newdentry = NULL; + struct dentry *upper = NULL; + umode_t mode = stat->mode; + int err; + + newdentry = ovl_lookup_temp(workdir, dentry); + err = PTR_ERR(newdentry); + if (IS_ERR(newdentry)) + goto out; + + upper = lookup_one_len(dentry->d_name.name, upperdir, + dentry->d_name.len); + err = PTR_ERR(upper); + if (IS_ERR(upper)) + goto out1; + + /* Can't properly set mode on creation because of the umask */ + stat->mode &= S_IFMT; + err = ovl_create_real(wdir, newdentry, stat, link, NULL, true); + stat->mode = mode; + if (err) + goto out2; + + if (S_ISREG(stat->mode)) { + struct path upperpath; + ovl_path_upper(dentry, &upperpath); + BUG_ON(upperpath.dentry != NULL); + upperpath.dentry = newdentry; + + err = ovl_copy_up_data(lowerpath, &upperpath, stat->size); + if (err) + goto out_cleanup; + } + + err = ovl_copy_xattr(lowerpath->dentry, newdentry); + if (err) + goto out_cleanup; + + mutex_lock(&newdentry->d_inode->i_mutex); + err = ovl_set_attr(newdentry, stat); + if (!err && attr) + err = notify_change(newdentry, attr, NULL); + mutex_unlock(&newdentry->d_inode->i_mutex); + if (err) + goto out_cleanup; + + err = ovl_do_rename(wdir, newdentry, udir, upper, 0); + if (err) + goto out_cleanup; + + ovl_dentry_update(dentry, newdentry); + newdentry = NULL; + + /* + * Non-directores become opaque when copied up. + */ + if (!S_ISDIR(stat->mode)) + ovl_dentry_set_opaque(dentry, true); +out2: + dput(upper); +out1: + dput(newdentry); +out: + return err; + +out_cleanup: + ovl_cleanup(wdir, newdentry); + goto out; +} + +/* + * Copy up a single dentry + * + * Directory renames only allowed on "pure upper" (already created on + * upper filesystem, never copied up). Directories which are on lower or + * are merged may not be renamed. For these -EXDEV is returned and + * userspace has to deal with it. This means, when copying up a + * directory we can rely on it and ancestors being stable. + * + * Non-directory renames start with copy up of source if necessary. The + * actual rename will only proceed once the copy up was successful. Copy + * up uses upper parent i_mutex for exclusion. Since rename can change + * d_parent it is possible that the copy up will lock the old parent. At + * that point the file will have already been copied up anyway. + */ +int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, + struct path *lowerpath, struct kstat *stat, + struct iattr *attr) +{ + struct dentry *workdir = ovl_workdir(dentry); + int err; + struct kstat pstat; + struct path parentpath; + struct dentry *upperdir; + struct dentry *upperdentry; + const struct cred *old_cred; + struct cred *override_cred; + char *link = NULL; + + ovl_path_upper(parent, &parentpath); + upperdir = parentpath.dentry; + + err = vfs_getattr(&parentpath, &pstat); + if (err) + return err; + + if (S_ISLNK(stat->mode)) { + link = ovl_read_symlink(lowerpath->dentry); + if (IS_ERR(link)) + return PTR_ERR(link); + } + + err = -ENOMEM; + override_cred = prepare_creds(); + if (!override_cred) + goto out_free_link; + + override_cred->fsuid = stat->uid; + override_cred->fsgid = stat->gid; + /* + * CAP_SYS_ADMIN for copying up extended attributes + * CAP_DAC_OVERRIDE for create + * CAP_FOWNER for chmod, timestamp update + * CAP_FSETID for chmod + * CAP_CHOWN for chown + * CAP_MKNOD for mknod + */ + cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN); + cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE); + cap_raise(override_cred->cap_effective, CAP_FOWNER); + cap_raise(override_cred->cap_effective, CAP_FSETID); + cap_raise(override_cred->cap_effective, CAP_CHOWN); + cap_raise(override_cred->cap_effective, CAP_MKNOD); + old_cred = override_creds(override_cred); + + err = -EIO; + if (lock_rename(workdir, upperdir) != NULL) { + pr_err("overlayfs: failed to lock workdir+upperdir\n"); + goto out_unlock; + } + upperdentry = ovl_dentry_upper(dentry); + if (upperdentry) { + unlock_rename(workdir, upperdir); + err = 0; + /* Raced with another copy-up? Do the setattr here */ + if (attr) { + mutex_lock(&upperdentry->d_inode->i_mutex); + err = notify_change(upperdentry, attr, NULL); + mutex_unlock(&upperdentry->d_inode->i_mutex); + } + goto out_put_cred; + } + + err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath, + stat, attr, link); + if (!err) { + /* Restore timestamps on parent (best effort) */ + ovl_set_timestamps(upperdir, &pstat); + } +out_unlock: + unlock_rename(workdir, upperdir); +out_put_cred: + revert_creds(old_cred); + put_cred(override_cred); + +out_free_link: + if (link) + free_page((unsigned long) link); + + return err; +} + +int ovl_copy_up(struct dentry *dentry) +{ + int err; + + err = 0; + while (!err) { + struct dentry *next; + struct dentry *parent; + struct path lowerpath; + struct kstat stat; + enum ovl_path_type type = ovl_path_type(dentry); + + if (OVL_TYPE_UPPER(type)) + break; + + next = dget(dentry); + /* find the topmost dentry not yet copied up */ + for (;;) { + parent = dget_parent(next); + + type = ovl_path_type(parent); + if (OVL_TYPE_UPPER(type)) + break; + + dput(next); + next = parent; + } + + ovl_path_lower(next, &lowerpath); + err = vfs_getattr(&lowerpath, &stat); + if (!err) + err = ovl_copy_up_one(parent, next, &lowerpath, &stat, NULL); + + dput(parent); + dput(next); + } + + return err; +} diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c new file mode 100644 index 000000000000..0dc4c33a0a1b --- /dev/null +++ b/fs/overlayfs/dir.c @@ -0,0 +1,928 @@ +/* + * + * Copyright (C) 2011 Novell Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include <linux/fs.h> +#include <linux/namei.h> +#include <linux/xattr.h> +#include <linux/security.h> +#include <linux/cred.h> +#include "overlayfs.h" + +void ovl_cleanup(struct inode *wdir, struct dentry *wdentry) +{ + int err; + + dget(wdentry); + if (S_ISDIR(wdentry->d_inode->i_mode)) + err = ovl_do_rmdir(wdir, wdentry); + else + err = ovl_do_unlink(wdir, wdentry); + dput(wdentry); + + if (err) { + pr_err("overlayfs: cleanup of '%pd2' failed (%i)\n", + wdentry, err); + } +} + +struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry) +{ + struct dentry *temp; + char name[20]; + + snprintf(name, sizeof(name), "#%lx", (unsigned long) dentry); + + temp = lookup_one_len(name, workdir, strlen(name)); + if (!IS_ERR(temp) && temp->d_inode) { + pr_err("overlayfs: workdir/%s already exists\n", name); + dput(temp); + temp = ERR_PTR(-EIO); + } + + return temp; +} + +/* caller holds i_mutex on workdir */ +static struct dentry *ovl_whiteout(struct dentry *workdir, + struct dentry *dentry) +{ + int err; + struct dentry *whiteout; + struct inode *wdir = workdir->d_inode; + + whiteout = ovl_lookup_temp(workdir, dentry); + if (IS_ERR(whiteout)) + return whiteout; + + err = ovl_do_whiteout(wdir, whiteout); + if (err) { + dput(whiteout); + whiteout = ERR_PTR(err); + } + + return whiteout; +} + +int ovl_create_real(struct inode *dir, struct dentry *newdentry, + struct kstat *stat, const char *link, + struct dentry *hardlink, bool debug) +{ + int err; + + if (newdentry->d_inode) + return -ESTALE; + + if (hardlink) { + err = ovl_do_link(hardlink, dir, newdentry, debug); + } else { + switch (stat->mode & S_IFMT) { + case S_IFREG: + err = ovl_do_create(dir, newdentry, stat->mode, debug); + break; + + case S_IFDIR: + err = ovl_do_mkdir(dir, newdentry, stat->mode, debug); + break; + + case S_IFCHR: + case S_IFBLK: + case S_IFIFO: + case S_IFSOCK: + err = ovl_do_mknod(dir, newdentry, + stat->mode, stat->rdev, debug); + break; + + case S_IFLNK: + err = ovl_do_symlink(dir, newdentry, link, debug); + break; + + default: + err = -EPERM; + } + } + if (!err && WARN_ON(!newdentry->d_inode)) { + /* + * Not quite sure if non-instantiated dentry is legal or not. + * VFS doesn't seem to care so check and warn here. + */ + err = -ENOENT; + } + return err; +} + +static int ovl_set_opaque(struct dentry *upperdentry) +{ + return ovl_do_setxattr(upperdentry, OVL_XATTR_OPAQUE, "y", 1, 0); +} + +static void ovl_remove_opaque(struct dentry *upperdentry) +{ + int err; + + err = ovl_do_removexattr(upperdentry, OVL_XATTR_OPAQUE); + if (err) { + pr_warn("overlayfs: failed to remove opaque from '%s' (%i)\n", + upperdentry->d_name.name, err); + } +} + +static int ovl_dir_getattr(struct vfsmount *mnt, struct dentry *dentry, + struct kstat *stat) +{ + int err; + enum ovl_path_type type; + struct path realpath; + + type = ovl_path_real(dentry, &realpath); + err = vfs_getattr(&realpath, stat); + if (err) + return err; + + stat->dev = dentry->d_sb->s_dev; + stat->ino = dentry->d_inode->i_ino; + + /* + * It's probably not worth it to count subdirs to get the + * correct link count. nlink=1 seems to pacify 'find' and + * other utilities. + */ + if (OVL_TYPE_MERGE(type)) + stat->nlink = 1; + + return 0; +} + +static int ovl_create_upper(struct dentry *dentry, struct inode *inode, + struct kstat *stat, const char *link, + struct dentry *hardlink) +{ + struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); + struct inode *udir = upperdir->d_inode; + struct dentry *newdentry; + int err; + + mutex_lock_nested(&udir->i_mutex, I_MUTEX_PARENT); + newdentry = lookup_one_len(dentry->d_name.name, upperdir, + dentry->d_name.len); + err = PTR_ERR(newdentry); + if (IS_ERR(newdentry)) + goto out_unlock; + err = ovl_create_real(udir, newdentry, stat, link, hardlink, false); + if (err) + goto out_dput; + + ovl_dentry_version_inc(dentry->d_parent); + ovl_dentry_update(dentry, newdentry); + ovl_copyattr(newdentry->d_inode, inode); + d_instantiate(dentry, inode); + newdentry = NULL; +out_dput: + dput(newdentry); +out_unlock: + mutex_unlock(&udir->i_mutex); + return err; +} + +static int ovl_lock_rename_workdir(struct dentry *workdir, + struct dentry *upperdir) +{ + /* Workdir should not be the same as upperdir */ + if (workdir == upperdir) + goto err; + + /* Workdir should not be subdir of upperdir and vice versa */ + if (lock_rename(workdir, upperdir) != NULL) + goto err_unlock; + + return 0; + +err_unlock: + unlock_rename(workdir, upperdir); +err: + pr_err("overlayfs: failed to lock workdir+upperdir\n"); + return -EIO; +} + +static struct dentry *ovl_clear_empty(struct dentry *dentry, + struct list_head *list) +{ + struct dentry *workdir = ovl_workdir(dentry); + struct inode *wdir = workdir->d_inode; + struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); + struct inode *udir = upperdir->d_inode; + struct path upperpath; + struct dentry *upper; + struct dentry *opaquedir; + struct kstat stat; + int err; + + err = ovl_lock_rename_workdir(workdir, upperdir); + if (err) + goto out; + + ovl_path_upper(dentry, &upperpath); + err = vfs_getattr(&upperpath, &stat); + if (err) + goto out_unlock; + + err = -ESTALE; + if (!S_ISDIR(stat.mode)) + goto out_unlock; + upper = upperpath.dentry; + if (upper->d_parent->d_inode != udir) + goto out_unlock; + + opaquedir = ovl_lookup_temp(workdir, dentry); + err = PTR_ERR(opaquedir); + if (IS_ERR(opaquedir)) + goto out_unlock; + + err = ovl_create_real(wdir, opaquedir, &stat, NULL, NULL, true); + if (err) + goto out_dput; + + err = ovl_copy_xattr(upper, opaquedir); + if (err) + goto out_cleanup; + + err = ovl_set_opaque(opaquedir); + if (err) + goto out_cleanup; + + mutex_lock(&opaquedir->d_inode->i_mutex); + err = ovl_set_attr(opaquedir, &stat); + mutex_unlock(&opaquedir->d_inode->i_mutex); + if (err) + goto out_cleanup; + + err = ovl_do_rename(wdir, opaquedir, udir, upper, RENAME_EXCHANGE); + if (err) + goto out_cleanup; + + ovl_cleanup_whiteouts(upper, list); + ovl_cleanup(wdir, upper); + unlock_rename(workdir, upperdir); + + /* dentry's upper doesn't match now, get rid of it */ + d_drop(dentry); + + return opaquedir; + +out_cleanup: + ovl_cleanup(wdir, opaquedir); +out_dput: + dput(opaquedir); +out_unlock: + unlock_rename(workdir, upperdir); +out: + return ERR_PTR(err); +} + +static struct dentry *ovl_check_empty_and_clear(struct dentry *dentry) +{ + int err; + struct dentry *ret = NULL; + LIST_HEAD(list); + + err = ovl_check_empty_dir(dentry, &list); + if (err) + ret = ERR_PTR(err); + else { + /* + * If no upperdentry then skip clearing whiteouts. + * + * Can race with copy-up, since we don't hold the upperdir + * mutex. Doesn't matter, since copy-up can't create a + * non-empty directory from an empty one. + */ + if (ovl_dentry_upper(dentry)) + ret = ovl_clear_empty(dentry, &list); + } + + ovl_cache_free(&list); + + return ret; +} + +static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, + struct kstat *stat, const char *link, + struct dentry *hardlink) +{ + struct dentry *workdir = ovl_workdir(dentry); + struct inode *wdir = workdir->d_inode; + struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); + struct inode *udir = upperdir->d_inode; + struct dentry *upper; + struct dentry *newdentry; + int err; + + err = ovl_lock_rename_workdir(workdir, upperdir); + if (err) + goto out; + + newdentry = ovl_lookup_temp(workdir, dentry); + err = PTR_ERR(newdentry); + if (IS_ERR(newdentry)) + goto out_unlock; + + upper = lookup_one_len(dentry->d_name.name, upperdir, + dentry->d_name.len); + err = PTR_ERR(upper); + if (IS_ERR(upper)) + goto out_dput; + + err = ovl_create_real(wdir, newdentry, stat, link, hardlink, true); + if (err) + goto out_dput2; + + if (S_ISDIR(stat->mode)) { + err = ovl_set_opaque(newdentry); + if (err) + goto out_cleanup; + + err = ovl_do_rename(wdir, newdentry, udir, upper, + RENAME_EXCHANGE); + if (err) + goto out_cleanup; + + ovl_cleanup(wdir, upper); + } else { + err = ovl_do_rename(wdir, newdentry, udir, upper, 0); + if (err) + goto out_cleanup; + } + ovl_dentry_version_inc(dentry->d_parent); + ovl_dentry_update(dentry, newdentry); + ovl_copyattr(newdentry->d_inode, inode); + d_instantiate(dentry, inode); + newdentry = NULL; +out_dput2: + dput(upper); +out_dput: + dput(newdentry); +out_unlock: + unlock_rename(workdir, upperdir); +out: + return err; + +out_cleanup: + ovl_cleanup(wdir, newdentry); + goto out_dput2; +} + +static int ovl_create_or_link(struct dentry *dentry, int mode, dev_t rdev, + const char *link, struct dentry *hardlink) +{ + int err; + struct inode *inode; + struct kstat stat = { + .mode = mode, + .rdev = rdev, + }; + + err = -ENOMEM; + inode = ovl_new_inode(dentry->d_sb, mode, dentry->d_fsdata); + if (!inode) + goto out; + + err = ovl_copy_up(dentry->d_parent); + if (err) + goto out_iput; + + if (!ovl_dentry_is_opaque(dentry)) { + err = ovl_create_upper(dentry, inode, &stat, link, hardlink); + } else { + const struct cred *old_cred; + struct cred *override_cred; + + err = -ENOMEM; + override_cred = prepare_creds(); + if (!override_cred) + goto out_iput; + + /* + * CAP_SYS_ADMIN for setting opaque xattr + * CAP_DAC_OVERRIDE for create in workdir, rename + * CAP_FOWNER for removing whiteout from sticky dir + */ + cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN); + cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE); + cap_raise(override_cred->cap_effective, CAP_FOWNER); + old_cred = override_creds(override_cred); + + err = ovl_create_over_whiteout(dentry, inode, &stat, link, + hardlink); + + revert_creds(old_cred); + put_cred(override_cred); + } + + if (!err) + inode = NULL; +out_iput: + iput(inode); +out: + return err; +} + +static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev, + const char *link) +{ + int err; + + err = ovl_want_write(dentry); + if (!err) { + err = ovl_create_or_link(dentry, mode, rdev, link, NULL); + ovl_drop_write(dentry); + } + + return err; +} + +static int ovl_create(struct inode *dir, struct dentry *dentry, umode_t mode, + bool excl) +{ + return ovl_create_object(dentry, (mode & 07777) | S_IFREG, 0, NULL); +} + +static int ovl_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + return ovl_create_object(dentry, (mode & 07777) | S_IFDIR, 0, NULL); +} + +static int ovl_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, + dev_t rdev) +{ + /* Don't allow creation of "whiteout" on overlay */ + if (S_ISCHR(mode) && rdev == WHITEOUT_DEV) + return -EPERM; + + return ovl_create_object(dentry, mode, rdev, NULL); +} + +static int ovl_symlink(struct inode *dir, struct dentry *dentry, + const char *link) +{ + return ovl_create_object(dentry, S_IFLNK, 0, link); +} + +static int ovl_link(struct dentry *old, struct inode *newdir, + struct dentry *new) +{ + int err; + struct dentry *upper; + + err = ovl_want_write(old); + if (err) + goto out; + + err = ovl_copy_up(old); + if (err) + goto out_drop_write; + + upper = ovl_dentry_upper(old); + err = ovl_create_or_link(new, upper->d_inode->i_mode, 0, NULL, upper); + +out_drop_write: + ovl_drop_write(old); +out: + return err; +} + +static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir) +{ + struct dentry *workdir = ovl_workdir(dentry); + struct inode *wdir = workdir->d_inode; + struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); + struct inode *udir = upperdir->d_inode; + struct dentry *whiteout; + struct dentry *upper; + struct dentry *opaquedir = NULL; + int err; + + if (is_dir && OVL_TYPE_MERGE_OR_LOWER(ovl_path_type(dentry))) { + opaquedir = ovl_check_empty_and_clear(dentry); + err = PTR_ERR(opaquedir); + if (IS_ERR(opaquedir)) + goto out; + } + + err = ovl_lock_rename_workdir(workdir, upperdir); + if (err) + goto out_dput; + + whiteout = ovl_whiteout(workdir, dentry); + err = PTR_ERR(whiteout); + if (IS_ERR(whiteout)) + goto out_unlock; + + upper = ovl_dentry_upper(dentry); + if (!upper) { + upper = lookup_one_len(dentry->d_name.name, upperdir, + dentry->d_name.len); + err = PTR_ERR(upper); + if (IS_ERR(upper)) + goto kill_whiteout; + + err = ovl_do_rename(wdir, whiteout, udir, upper, 0); + dput(upper); + if (err) + goto kill_whiteout; + } else { + int flags = 0; + + if (opaquedir) + upper = opaquedir; + err = -ESTALE; + if (upper->d_parent != upperdir) + goto kill_whiteout; + + if (is_dir) + flags |= RENAME_EXCHANGE; + + err = ovl_do_rename(wdir, whiteout, udir, upper, flags); + if (err) + goto kill_whiteout; + + if (is_dir) + ovl_cleanup(wdir, upper); + } + ovl_dentry_version_inc(dentry->d_parent); +out_d_drop: + d_drop(dentry); + dput(whiteout); +out_unlock: + unlock_rename(workdir, upperdir); +out_dput: + dput(opaquedir); +out: + return err; + +kill_whiteout: + ovl_cleanup(wdir, whiteout); + goto out_d_drop; +} + +static int ovl_remove_upper(struct dentry *dentry, bool is_dir) +{ + struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); + struct inode *dir = upperdir->d_inode; + struct dentry *upper = ovl_dentry_upper(dentry); + int err; + + mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); + err = -ESTALE; + if (upper->d_parent == upperdir) { + /* Don't let d_delete() think it can reset d_inode */ + dget(upper); + if (is_dir) + err = vfs_rmdir(dir, upper); + else + err = vfs_unlink(dir, upper, NULL); + dput(upper); + ovl_dentry_version_inc(dentry->d_parent); + } + + /* + * Keeping this dentry hashed would mean having to release + * upperpath/lowerpath, which could only be done if we are the + * sole user of this dentry. Too tricky... Just unhash for + * now. + */ + d_drop(dentry); + mutex_unlock(&dir->i_mutex); + + return err; +} + +static inline int ovl_check_sticky(struct dentry *dentry) +{ + struct inode *dir = ovl_dentry_real(dentry->d_parent)->d_inode; + struct inode *inode = ovl_dentry_real(dentry)->d_inode; + + if (check_sticky(dir, inode)) + return -EPERM; + + return 0; +} + +static int ovl_do_remove(struct dentry *dentry, bool is_dir) +{ + enum ovl_path_type type; + int err; + + err = ovl_check_sticky(dentry); + if (err) + goto out; + + err = ovl_want_write(dentry); + if (err) + goto out; + + err = ovl_copy_up(dentry->d_parent); + if (err) + goto out_drop_write; + + type = ovl_path_type(dentry); + if (OVL_TYPE_PURE_UPPER(type)) { + err = ovl_remove_upper(dentry, is_dir); + } else { + const struct cred *old_cred; + struct cred *override_cred; + + err = -ENOMEM; + override_cred = prepare_creds(); + if (!override_cred) + goto out_drop_write; + + /* + * CAP_SYS_ADMIN for setting xattr on whiteout, opaque dir + * CAP_DAC_OVERRIDE for create in workdir, rename + * CAP_FOWNER for removing whiteout from sticky dir + * CAP_FSETID for chmod of opaque dir + * CAP_CHOWN for chown of opaque dir + */ + cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN); + cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE); + cap_raise(override_cred->cap_effective, CAP_FOWNER); + cap_raise(override_cred->cap_effective, CAP_FSETID); + cap_raise(override_cred->cap_effective, CAP_CHOWN); + old_cred = override_creds(override_cred); + + err = ovl_remove_and_whiteout(dentry, is_dir); + + revert_creds(old_cred); + put_cred(override_cred); + } +out_drop_write: + ovl_drop_write(dentry); +out: + return err; +} + +static int ovl_unlink(struct inode *dir, struct dentry *dentry) +{ + return ovl_do_remove(dentry, false); +} + +static int ovl_rmdir(struct inode *dir, struct dentry *dentry) +{ + return ovl_do_remove(dentry, true); +} + +static int ovl_rename2(struct inode *olddir, struct dentry *old, + struct inode *newdir, struct dentry *new, + unsigned int flags) +{ + int err; + enum ovl_path_type old_type; + enum ovl_path_type new_type; + struct dentry *old_upperdir; + struct dentry *new_upperdir; + struct dentry *olddentry; + struct dentry *newdentry; + struct dentry *trap; + bool old_opaque; + bool new_opaque; + bool new_create = false; + bool cleanup_whiteout = false; + bool overwrite = !(flags & RENAME_EXCHANGE); + bool is_dir = S_ISDIR(old->d_inode->i_mode); + bool new_is_dir = false; + struct dentry *opaquedir = NULL; + const struct cred *old_cred = NULL; + struct cred *override_cred = NULL; + + err = -EINVAL; + if (flags & ~(RENAME_EXCHANGE | RENAME_NOREPLACE)) + goto out; + + flags &= ~RENAME_NOREPLACE; + + err = ovl_check_sticky(old); + if (err) + goto out; + + /* Don't copy up directory trees */ + old_type = ovl_path_type(old); + err = -EXDEV; + if (OVL_TYPE_MERGE_OR_LOWER(old_type) && is_dir) + goto out; + + if (new->d_inode) { + err = ovl_check_sticky(new); + if (err) + goto out; + + if (S_ISDIR(new->d_inode->i_mode)) + new_is_dir = true; + + new_type = ovl_path_type(new); + err = -EXDEV; + if (!overwrite && OVL_TYPE_MERGE_OR_LOWER(new_type) && new_is_dir) + goto out; + + err = 0; + if (!OVL_TYPE_UPPER(new_type) && !OVL_TYPE_UPPER(old_type)) { + if (ovl_dentry_lower(old)->d_inode == + ovl_dentry_lower(new)->d_inode) + goto out; + } + if (OVL_TYPE_UPPER(new_type) && OVL_TYPE_UPPER(old_type)) { + if (ovl_dentry_upper(old)->d_inode == + ovl_dentry_upper(new)->d_inode) + goto out; + } + } else { + if (ovl_dentry_is_opaque(new)) + new_type = __OVL_PATH_UPPER; + else + new_type = __OVL_PATH_UPPER | __OVL_PATH_PURE; + } + + err = ovl_want_write(old); + if (err) + goto out; + + err = ovl_copy_up(old); + if (err) + goto out_drop_write; + + err = ovl_copy_up(new->d_parent); + if (err) + goto out_drop_write; + if (!overwrite) { + err = ovl_copy_up(new); + if (err) + goto out_drop_write; + } + + old_opaque = !OVL_TYPE_PURE_UPPER(old_type); + new_opaque = !OVL_TYPE_PURE_UPPER(new_type); + + if (old_opaque || new_opaque) { + err = -ENOMEM; + override_cred = prepare_creds(); + if (!override_cred) + goto out_drop_write; + + /* + * CAP_SYS_ADMIN for setting xattr on whiteout, opaque dir + * CAP_DAC_OVERRIDE for create in workdir + * CAP_FOWNER for removing whiteout from sticky dir + * CAP_FSETID for chmod of opaque dir + * CAP_CHOWN for chown of opaque dir + */ + cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN); + cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE); + cap_raise(override_cred->cap_effective, CAP_FOWNER); + cap_raise(override_cred->cap_effective, CAP_FSETID); + cap_raise(override_cred->cap_effective, CAP_CHOWN); + old_cred = override_creds(override_cred); + } + + if (overwrite && OVL_TYPE_MERGE_OR_LOWER(new_type) && new_is_dir) { + opaquedir = ovl_check_empty_and_clear(new); + err = PTR_ERR(opaquedir); + if (IS_ERR(opaquedir)) { + opaquedir = NULL; + goto out_revert_creds; + } + } + + if (overwrite) { + if (old_opaque) { + if (new->d_inode || !new_opaque) { + /* Whiteout source */ + flags |= RENAME_WHITEOUT; + } else { + /* Switch whiteouts */ + flags |= RENAME_EXCHANGE; + } + } else if (is_dir && !new->d_inode && new_opaque) { + flags |= RENAME_EXCHANGE; + cleanup_whiteout = true; + } + } + + old_upperdir = ovl_dentry_upper(old->d_parent); + new_upperdir = ovl_dentry_upper(new->d_parent); + + trap = lock_rename(new_upperdir, old_upperdir); + + olddentry = ovl_dentry_upper(old); + newdentry = ovl_dentry_upper(new); + if (newdentry) { + if (opaquedir) { + newdentry = opaquedir; + opaquedir = NULL; + } else { + dget(newdentry); + } + } else { + new_create = true; + newdentry = lookup_one_len(new->d_name.name, new_upperdir, + new->d_name.len); + err = PTR_ERR(newdentry); + if (IS_ERR(newdentry)) + goto out_unlock; + } + + err = -ESTALE; + if (olddentry->d_parent != old_upperdir) + goto out_dput; + if (newdentry->d_parent != new_upperdir) + goto out_dput; + if (olddentry == trap) + goto out_dput; + if (newdentry == trap) + goto out_dput; + + if (is_dir && !old_opaque && new_opaque) { + err = ovl_set_opaque(olddentry); + if (err) + goto out_dput; + } + if (!overwrite && new_is_dir && old_opaque && !new_opaque) { + err = ovl_set_opaque(newdentry); + if (err) + goto out_dput; + } + + if (old_opaque || new_opaque) { + err = ovl_do_rename(old_upperdir->d_inode, olddentry, + new_upperdir->d_inode, newdentry, + flags); + } else { + /* No debug for the plain case */ + BUG_ON(flags & ~RENAME_EXCHANGE); + err = vfs_rename(old_upperdir->d_inode, olddentry, + new_upperdir->d_inode, newdentry, + NULL, flags); + } + + if (err) { + if (is_dir && !old_opaque && new_opaque) + ovl_remove_opaque(olddentry); + if (!overwrite && new_is_dir && old_opaque && !new_opaque) + ovl_remove_opaque(newdentry); + goto out_dput; + } + + if (is_dir && old_opaque && !new_opaque) + ovl_remove_opaque(olddentry); + if (!overwrite && new_is_dir && !old_opaque && new_opaque) + ovl_remove_opaque(newdentry); + + if (old_opaque != new_opaque) { + ovl_dentry_set_opaque(old, new_opaque); + if (!overwrite) + ovl_dentry_set_opaque(new, old_opaque); + } + + if (cleanup_whiteout) + ovl_cleanup(old_upperdir->d_inode, newdentry); + + ovl_dentry_version_inc(old->d_parent); + ovl_dentry_version_inc(new->d_parent); + +out_dput: + dput(newdentry); +out_unlock: + unlock_rename(new_upperdir, old_upperdir); +out_revert_creds: + if (old_opaque || new_opaque) { + revert_creds(old_cred); + put_cred(override_cred); + } +out_drop_write: + ovl_drop_write(old); +out: + dput(opaquedir); + return err; +} + +const struct inode_operations ovl_dir_inode_operations = { + .lookup = ovl_lookup, + .mkdir = ovl_mkdir, + .symlink = ovl_symlink, + .unlink = ovl_unlink, + .rmdir = ovl_rmdir, + .rename2 = ovl_rename2, + .link = ovl_link, + .setattr = ovl_setattr, + .create = ovl_create, + .mknod = ovl_mknod, + .permission = ovl_permission, + .getattr = ovl_dir_getattr, + .setxattr = ovl_setxattr, + .getxattr = ovl_getxattr, + .listxattr = ovl_listxattr, + .removexattr = ovl_removexattr, +}; diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c new file mode 100644 index 000000000000..04f124884687 --- /dev/null +++ b/fs/overlayfs/inode.c @@ -0,0 +1,436 @@ +/* + * + * Copyright (C) 2011 Novell Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/xattr.h> +#include "overlayfs.h" + +static int ovl_copy_up_last(struct dentry *dentry, struct iattr *attr, + bool no_data) +{ + int err; + struct dentry *parent; + struct kstat stat; + struct path lowerpath; + + parent = dget_parent(dentry); + err = ovl_copy_up(parent); + if (err) + goto out_dput_parent; + + ovl_path_lower(dentry, &lowerpath); + err = vfs_getattr(&lowerpath, &stat); + if (err) + goto out_dput_parent; + + if (no_data) + stat.size = 0; + + err = ovl_copy_up_one(parent, dentry, &lowerpath, &stat, attr); + +out_dput_parent: + dput(parent); + return err; +} + +int ovl_setattr(struct dentry *dentry, struct iattr *attr) +{ + int err; + struct dentry *upperdentry; + + err = ovl_want_write(dentry); + if (err) + goto out; + + upperdentry = ovl_dentry_upper(dentry); + if (upperdentry) { + mutex_lock(&upperdentry->d_inode->i_mutex); + err = notify_change(upperdentry, attr, NULL); + mutex_unlock(&upperdentry->d_inode->i_mutex); + } else { + err = ovl_copy_up_last(dentry, attr, false); + } + ovl_drop_write(dentry); +out: + return err; +} + +static int ovl_getattr(struct vfsmount *mnt, struct dentry *dentry, + struct kstat *stat) +{ + struct path realpath; + + ovl_path_real(dentry, &realpath); + return vfs_getattr(&realpath, stat); +} + +int ovl_permission(struct inode *inode, int mask) +{ + struct ovl_entry *oe; + struct dentry *alias = NULL; + struct inode *realinode; + struct dentry *realdentry; + bool is_upper; + int err; + + if (S_ISDIR(inode->i_mode)) { + oe = inode->i_private; + } else if (mask & MAY_NOT_BLOCK) { + return -ECHILD; + } else { + /* + * For non-directories find an alias and get the info + * from there. + */ + alias = d_find_any_alias(inode); + if (WARN_ON(!alias)) + return -ENOENT; + + oe = alias->d_fsdata; + } + + realdentry = ovl_entry_real(oe, &is_upper); + + /* Careful in RCU walk mode */ + realinode = ACCESS_ONCE(realdentry->d_inode); + if (!realinode) { + WARN_ON(!(mask & MAY_NOT_BLOCK)); + err = -ENOENT; + goto out_dput; + } + + if (mask & MAY_WRITE) { + umode_t mode = realinode->i_mode; + + /* + * Writes will always be redirected to upper layer, so + * ignore lower layer being read-only. + * + * If the overlay itself is read-only then proceed + * with the permission check, don't return EROFS. + * This will only happen if this is the lower layer of + * another overlayfs. + * + * If upper fs becomes read-only after the overlay was + * constructed return EROFS to prevent modification of + * upper layer. + */ + err = -EROFS; + if (is_upper && !IS_RDONLY(inode) && IS_RDONLY(realinode) && + (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) + goto out_dput; + } + + err = __inode_permission(realinode, mask); +out_dput: + dput(alias); + return err; +} + + +struct ovl_link_data { + struct dentry *realdentry; + void *cookie; +}; + +static void *ovl_follow_link(struct dentry *dentry, struct nameidata *nd) +{ + void *ret; + struct dentry *realdentry; + struct inode *realinode; + + realdentry = ovl_dentry_real(dentry); + realinode = realdentry->d_inode; + + if (WARN_ON(!realinode->i_op->follow_link)) + return ERR_PTR(-EPERM); + + ret = realinode->i_op->follow_link(realdentry, nd); + if (IS_ERR(ret)) + return ret; + + if (realinode->i_op->put_link) { + struct ovl_link_data *data; + + data = kmalloc(sizeof(struct ovl_link_data), GFP_KERNEL); + if (!data) { + realinode->i_op->put_link(realdentry, nd, ret); + return ERR_PTR(-ENOMEM); + } + data->realdentry = realdentry; + data->cookie = ret; + + return data; + } else { + return NULL; + } +} + +static void ovl_put_link(struct dentry *dentry, struct nameidata *nd, void *c) +{ + struct inode *realinode; + struct ovl_link_data *data = c; + + if (!data) + return; + + realinode = data->realdentry->d_inode; + realinode->i_op->put_link(data->realdentry, nd, data->cookie); + kfree(data); +} + +static int ovl_readlink(struct dentry *dentry, char __user *buf, int bufsiz) +{ + struct path realpath; + struct inode *realinode; + + ovl_path_real(dentry, &realpath); + realinode = realpath.dentry->d_inode; + + if (!realinode->i_op->readlink) + return -EINVAL; + + touch_atime(&realpath); + + return realinode->i_op->readlink(realpath.dentry, buf, bufsiz); +} + + +static bool ovl_is_private_xattr(const char *name) +{ + return strncmp(name, OVL_XATTR_PRE_NAME, OVL_XATTR_PRE_LEN) == 0; +} + +int ovl_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) +{ + int err; + struct dentry *upperdentry; + + err = ovl_want_write(dentry); + if (err) + goto out; + + err = -EPERM; + if (ovl_is_private_xattr(name)) + goto out_drop_write; + + err = ovl_copy_up(dentry); + if (err) + goto out_drop_write; + + upperdentry = ovl_dentry_upper(dentry); + err = vfs_setxattr(upperdentry, name, value, size, flags); + +out_drop_write: + ovl_drop_write(dentry); +out: + return err; +} + +static bool ovl_need_xattr_filter(struct dentry *dentry, + enum ovl_path_type type) +{ + if ((type & (__OVL_PATH_PURE | __OVL_PATH_UPPER)) == __OVL_PATH_UPPER) + return S_ISDIR(dentry->d_inode->i_mode); + else + return false; +} + +ssize_t ovl_getxattr(struct dentry *dentry, const char *name, + void *value, size_t size) +{ + struct path realpath; + enum ovl_path_type type = ovl_path_real(dentry, &realpath); + + if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name)) + return -ENODATA; + + return vfs_getxattr(realpath.dentry, name, value, size); +} + +ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) +{ + struct path realpath; + enum ovl_path_type type = ovl_path_real(dentry, &realpath); + ssize_t res; + int off; + + res = vfs_listxattr(realpath.dentry, list, size); + if (res <= 0 || size == 0) + return res; + + if (!ovl_need_xattr_filter(dentry, type)) + return res; + + /* filter out private xattrs */ + for (off = 0; off < res;) { + char *s = list + off; + size_t slen = strlen(s) + 1; + + BUG_ON(off + slen > res); + + if (ovl_is_private_xattr(s)) { + res -= slen; + memmove(s, s + slen, res - off); + } else { + off += slen; + } + } + + return res; +} + +int ovl_removexattr(struct dentry *dentry, const char *name) +{ + int err; + struct path realpath; + enum ovl_path_type type = ovl_path_real(dentry, &realpath); + + err = ovl_want_write(dentry); + if (err) + goto out; + + err = -ENODATA; + if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name)) + goto out_drop_write; + + if (!OVL_TYPE_UPPER(type)) { + err = vfs_getxattr(realpath.dentry, name, NULL, 0); + if (err < 0) + goto out_drop_write; + + err = ovl_copy_up(dentry); + if (err) + goto out_drop_write; + + ovl_path_upper(dentry, &realpath); + } + + err = vfs_removexattr(realpath.dentry, name); +out_drop_write: + ovl_drop_write(dentry); +out: + return err; +} + +static bool ovl_open_need_copy_up(int flags, enum ovl_path_type type, + struct dentry *realdentry) +{ + if (OVL_TYPE_UPPER(type)) + return false; + + if (special_file(realdentry->d_inode->i_mode)) + return false; + + if (!(OPEN_FMODE(flags) & FMODE_WRITE) && !(flags & O_TRUNC)) + return false; + + return true; +} + +static int ovl_dentry_open(struct dentry *dentry, struct file *file, + const struct cred *cred) +{ + int err; + struct path realpath; + enum ovl_path_type type; + bool want_write = false; + + type = ovl_path_real(dentry, &realpath); + if (ovl_open_need_copy_up(file->f_flags, type, realpath.dentry)) { + want_write = true; + err = ovl_want_write(dentry); + if (err) + goto out; + + if (file->f_flags & O_TRUNC) + err = ovl_copy_up_last(dentry, NULL, true); + else + err = ovl_copy_up(dentry); + if (err) + goto out_drop_write; + + ovl_path_upper(dentry, &realpath); + } + + err = vfs_open(&realpath, file, cred); +out_drop_write: + if (want_write) + ovl_drop_write(dentry); +out: + return err; +} + +static const struct inode_operations ovl_file_inode_operations = { + .setattr = ovl_setattr, + .permission = ovl_permission, + .getattr = ovl_getattr, + .setxattr = ovl_setxattr, + .getxattr = ovl_getxattr, + .listxattr = ovl_listxattr, + .removexattr = ovl_removexattr, + .dentry_open = ovl_dentry_open, +}; + +static const struct inode_operations ovl_symlink_inode_operations = { + .setattr = ovl_setattr, + .follow_link = ovl_follow_link, + .put_link = ovl_put_link, + .readlink = ovl_readlink, + .getattr = ovl_getattr, + .setxattr = ovl_setxattr, + .getxattr = ovl_getxattr, + .listxattr = ovl_listxattr, + .removexattr = ovl_removexattr, +}; + +struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, + struct ovl_entry *oe) +{ + struct inode *inode; + + inode = new_inode(sb); + if (!inode) + return NULL; + + mode &= S_IFMT; + + inode->i_ino = get_next_ino(); + inode->i_mode = mode; + inode->i_flags |= S_NOATIME | S_NOCMTIME; + + switch (mode) { + case S_IFDIR: + inode->i_private = oe; + inode->i_op = &ovl_dir_inode_operations; + inode->i_fop = &ovl_dir_operations; + break; + + case S_IFLNK: + inode->i_op = &ovl_symlink_inode_operations; + break; + + case S_IFREG: + case S_IFSOCK: + case S_IFBLK: + case S_IFCHR: + case S_IFIFO: + inode->i_op = &ovl_file_inode_operations; + break; + + default: + WARN(1, "illegal file type: %i\n", mode); + iput(inode); + inode = NULL; + } + + return inode; +} diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h new file mode 100644 index 000000000000..17ac5afc9ffb --- /dev/null +++ b/fs/overlayfs/overlayfs.h @@ -0,0 +1,199 @@ +/* + * + * Copyright (C) 2011 Novell Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include <linux/kernel.h> + +struct ovl_entry; + +enum ovl_path_type { + __OVL_PATH_PURE = (1 << 0), + __OVL_PATH_UPPER = (1 << 1), + __OVL_PATH_MERGE = (1 << 2), +}; + +#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER) +#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE) +#define OVL_TYPE_PURE_UPPER(type) ((type) & __OVL_PATH_PURE) +#define OVL_TYPE_MERGE_OR_LOWER(type) \ + (OVL_TYPE_MERGE(type) || !OVL_TYPE_UPPER(type)) + +#define OVL_XATTR_PRE_NAME "trusted.overlay." +#define OVL_XATTR_PRE_LEN 16 +#define OVL_XATTR_OPAQUE OVL_XATTR_PRE_NAME"opaque" + +static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry) +{ + int err = vfs_rmdir(dir, dentry); + pr_debug("rmdir(%pd2) = %i\n", dentry, err); + return err; +} + +static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry) +{ + int err = vfs_unlink(dir, dentry, NULL); + pr_debug("unlink(%pd2) = %i\n", dentry, err); + return err; +} + +static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *new_dentry, bool debug) +{ + int err = vfs_link(old_dentry, dir, new_dentry, NULL); + if (debug) { + pr_debug("link(%pd2, %pd2) = %i\n", + old_dentry, new_dentry, err); + } + return err; +} + +static inline int ovl_do_create(struct inode *dir, struct dentry *dentry, + umode_t mode, bool debug) +{ + int err = vfs_create(dir, dentry, mode, true); + if (debug) + pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err); + return err; +} + +static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry, + umode_t mode, bool debug) +{ + int err = vfs_mkdir(dir, dentry, mode); + if (debug) + pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err); + return err; +} + +static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry, + umode_t mode, dev_t dev, bool debug) +{ + int err = vfs_mknod(dir, dentry, mode, dev); + if (debug) { + pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", + dentry, mode, dev, err); + } + return err; +} + +static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry, + const char *oldname, bool debug) +{ + int err = vfs_symlink(dir, dentry, oldname); + if (debug) + pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); + return err; +} + +static inline int ovl_do_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) +{ + int err = vfs_setxattr(dentry, name, value, size, flags); + pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n", + dentry, name, (int) size, (char *) value, flags, err); + return err; +} + +static inline int ovl_do_removexattr(struct dentry *dentry, const char *name) +{ + int err = vfs_removexattr(dentry, name); + pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err); + return err; +} + +static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry, + struct inode *newdir, struct dentry *newdentry, + unsigned int flags) +{ + int err; + + pr_debug("rename2(%pd2, %pd2, 0x%x)\n", + olddentry, newdentry, flags); + + err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags); + + if (err) { + pr_debug("...rename2(%pd2, %pd2, ...) = %i\n", + olddentry, newdentry, err); + } + return err; +} + +static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry) +{ + int err = vfs_whiteout(dir, dentry); + pr_debug("whiteout(%pd2) = %i\n", dentry, err); + return err; +} + +enum ovl_path_type ovl_path_type(struct dentry *dentry); +u64 ovl_dentry_version_get(struct dentry *dentry); +void ovl_dentry_version_inc(struct dentry *dentry); +void ovl_path_upper(struct dentry *dentry, struct path *path); +void ovl_path_lower(struct dentry *dentry, struct path *path); +enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); +int ovl_path_next(int idx, struct dentry *dentry, struct path *path); +struct dentry *ovl_dentry_upper(struct dentry *dentry); +struct dentry *ovl_dentry_lower(struct dentry *dentry); +struct dentry *ovl_dentry_real(struct dentry *dentry); +struct dentry *ovl_entry_real(struct ovl_entry *oe, bool *is_upper); +struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry); +void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache); +struct dentry *ovl_workdir(struct dentry *dentry); +int ovl_want_write(struct dentry *dentry); +void ovl_drop_write(struct dentry *dentry); +bool ovl_dentry_is_opaque(struct dentry *dentry); +void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque); +bool ovl_is_whiteout(struct dentry *dentry); +void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry); +struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, + unsigned int flags); +struct file *ovl_path_open(struct path *path, int flags); + +struct dentry *ovl_upper_create(struct dentry *upperdir, struct dentry *dentry, + struct kstat *stat, const char *link); + +/* readdir.c */ +extern const struct file_operations ovl_dir_operations; +int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); +void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list); +void ovl_cache_free(struct list_head *list); + +/* inode.c */ +int ovl_setattr(struct dentry *dentry, struct iattr *attr); +int ovl_permission(struct inode *inode, int mask); +int ovl_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags); +ssize_t ovl_getxattr(struct dentry *dentry, const char *name, + void *value, size_t size); +ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); +int ovl_removexattr(struct dentry *dentry, const char *name); + +struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, + struct ovl_entry *oe); +static inline void ovl_copyattr(struct inode *from, struct inode *to) +{ + to->i_uid = from->i_uid; + to->i_gid = from->i_gid; +} + +/* dir.c */ +extern const struct inode_operations ovl_dir_inode_operations; +struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry); +int ovl_create_real(struct inode *dir, struct dentry *newdentry, + struct kstat *stat, const char *link, + struct dentry *hardlink, bool debug); +void ovl_cleanup(struct inode *dir, struct dentry *dentry); + +/* copy_up.c */ +int ovl_copy_up(struct dentry *dentry); +int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, + struct path *lowerpath, struct kstat *stat, + struct iattr *attr); +int ovl_copy_xattr(struct dentry *old, struct dentry *new); +int ovl_set_attr(struct dentry *upper, struct kstat *stat); diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c new file mode 100644 index 000000000000..907870e81a72 --- /dev/null +++ b/fs/overlayfs/readdir.c @@ -0,0 +1,557 @@ +/* + * + * Copyright (C) 2011 Novell Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/namei.h> +#include <linux/file.h> +#include <linux/xattr.h> +#include <linux/rbtree.h> +#include <linux/security.h> +#include <linux/cred.h> +#include "overlayfs.h" + +struct ovl_cache_entry { + unsigned int len; + unsigned int type; + u64 ino; + struct list_head l_node; + struct rb_node node; + bool is_whiteout; + char name[]; +}; + +struct ovl_dir_cache { + long refcount; + u64 version; + struct list_head entries; +}; + +struct ovl_readdir_data { + struct dir_context ctx; + bool is_merge; + struct rb_root root; + struct list_head *list; + struct list_head middle; + struct dentry *dir; + int count; + int err; +}; + +struct ovl_dir_file { + bool is_real; + bool is_upper; + struct ovl_dir_cache *cache; + struct list_head *cursor; + struct file *realfile; + struct file *upperfile; +}; + +static struct ovl_cache_entry *ovl_cache_entry_from_node(struct rb_node *n) +{ + return container_of(n, struct ovl_cache_entry, node); +} + +static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root, + const char *name, int len) +{ + struct rb_node *node = root->rb_node; + int cmp; + + while (node) { + struct ovl_cache_entry *p = ovl_cache_entry_from_node(node); + + cmp = strncmp(name, p->name, len); + if (cmp > 0) + node = p->node.rb_right; + else if (cmp < 0 || len < p->len) + node = p->node.rb_left; + else + return p; + } + + return NULL; +} + +static struct ovl_cache_entry *ovl_cache_entry_new(struct dentry *dir, + const char *name, int len, + u64 ino, unsigned int d_type) +{ + struct ovl_cache_entry *p; + size_t size = offsetof(struct ovl_cache_entry, name[len + 1]); + + p = kmalloc(size, GFP_KERNEL); + if (!p) + return NULL; + + memcpy(p->name, name, len); + p->name[len] = '\0'; + p->len = len; + p->type = d_type; + p->ino = ino; + p->is_whiteout = false; + + if (d_type == DT_CHR) { + struct dentry *dentry; + const struct cred *old_cred; + struct cred *override_cred; + + override_cred = prepare_creds(); + if (!override_cred) { + kfree(p); + return NULL; + } + + /* + * CAP_DAC_OVERRIDE for lookup + */ + cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE); + old_cred = override_creds(override_cred); + + dentry = lookup_one_len(name, dir, len); + if (!IS_ERR(dentry)) { + p->is_whiteout = ovl_is_whiteout(dentry); + dput(dentry); + } + revert_creds(old_cred); + put_cred(override_cred); + } + return p; +} + +static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd, + const char *name, int len, u64 ino, + unsigned int d_type) +{ + struct rb_node **newp = &rdd->root.rb_node; + struct rb_node *parent = NULL; + struct ovl_cache_entry *p; + + while (*newp) { + int cmp; + struct ovl_cache_entry *tmp; + + parent = *newp; + tmp = ovl_cache_entry_from_node(*newp); + cmp = strncmp(name, tmp->name, len); + if (cmp > 0) + newp = &tmp->node.rb_right; + else if (cmp < 0 || len < tmp->len) + newp = &tmp->node.rb_left; + else + return 0; + } + + p = ovl_cache_entry_new(rdd->dir, name, len, ino, d_type); + if (p == NULL) + return -ENOMEM; + + list_add_tail(&p->l_node, rdd->list); + rb_link_node(&p->node, parent, newp); + rb_insert_color(&p->node, &rdd->root); + + return 0; +} + +static int ovl_fill_lower(struct ovl_readdir_data *rdd, + const char *name, int namelen, + loff_t offset, u64 ino, unsigned int d_type) +{ + struct ovl_cache_entry *p; + + p = ovl_cache_entry_find(&rdd->root, name, namelen); + if (p) { + list_move_tail(&p->l_node, &rdd->middle); + } else { + p = ovl_cache_entry_new(rdd->dir, name, namelen, ino, d_type); + if (p == NULL) + rdd->err = -ENOMEM; + else + list_add_tail(&p->l_node, &rdd->middle); + } + + return rdd->err; +} + +void ovl_cache_free(struct list_head *list) +{ + struct ovl_cache_entry *p; + struct ovl_cache_entry *n; + + list_for_each_entry_safe(p, n, list, l_node) + kfree(p); + + INIT_LIST_HEAD(list); +} + +static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry) +{ + struct ovl_dir_cache *cache = od->cache; + + WARN_ON(cache->refcount <= 0); + cache->refcount--; + if (!cache->refcount) { + if (ovl_dir_cache(dentry) == cache) + ovl_set_dir_cache(dentry, NULL); + + ovl_cache_free(&cache->entries); + kfree(cache); + } +} + +static int ovl_fill_merge(struct dir_context *ctx, const char *name, + int namelen, loff_t offset, u64 ino, + unsigned int d_type) +{ + struct ovl_readdir_data *rdd = + container_of(ctx, struct ovl_readdir_data, ctx); + + rdd->count++; + if (!rdd->is_merge) + return ovl_cache_entry_add_rb(rdd, name, namelen, ino, d_type); + else + return ovl_fill_lower(rdd, name, namelen, offset, ino, d_type); +} + +static inline int ovl_dir_read(struct path *realpath, + struct ovl_readdir_data *rdd) +{ + struct file *realfile; + int err; + + realfile = ovl_path_open(realpath, O_RDONLY | O_DIRECTORY); + if (IS_ERR(realfile)) + return PTR_ERR(realfile); + + rdd->dir = realpath->dentry; + rdd->ctx.pos = 0; + do { + rdd->count = 0; + rdd->err = 0; + err = iterate_dir(realfile, &rdd->ctx); + if (err >= 0) + err = rdd->err; + } while (!err && rdd->count); + fput(realfile); + + return err; +} + +static void ovl_dir_reset(struct file *file) +{ + struct ovl_dir_file *od = file->private_data; + struct ovl_dir_cache *cache = od->cache; + struct dentry *dentry = file->f_path.dentry; + enum ovl_path_type type = ovl_path_type(dentry); + + if (cache && ovl_dentry_version_get(dentry) != cache->version) { + ovl_cache_put(od, dentry); + od->cache = NULL; + od->cursor = NULL; + } + WARN_ON(!od->is_real && !OVL_TYPE_MERGE(type)); + if (od->is_real && OVL_TYPE_MERGE(type)) + od->is_real = false; +} + +static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list) +{ + int err; + struct path realpath; + struct ovl_readdir_data rdd = { + .ctx.actor = ovl_fill_merge, + .list = list, + .root = RB_ROOT, + .is_merge = false, + }; + int idx, next; + + for (idx = 0; idx != -1; idx = next) { + next = ovl_path_next(idx, dentry, &realpath); + + if (next != -1) { + err = ovl_dir_read(&realpath, &rdd); + if (err) + break; + } else { + /* + * Insert lowest layer entries before upper ones, this + * allows offsets to be reasonably constant + */ + list_add(&rdd.middle, rdd.list); + rdd.is_merge = true; + err = ovl_dir_read(&realpath, &rdd); + list_del(&rdd.middle); + } + } + return err; +} + +static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos) +{ + struct list_head *p; + loff_t off = 0; + + list_for_each(p, &od->cache->entries) { + if (off >= pos) + break; + off++; + } + /* Cursor is safe since the cache is stable */ + od->cursor = p; +} + +static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry) +{ + int res; + struct ovl_dir_cache *cache; + + cache = ovl_dir_cache(dentry); + if (cache && ovl_dentry_version_get(dentry) == cache->version) { + cache->refcount++; + return cache; + } + ovl_set_dir_cache(dentry, NULL); + + cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL); + if (!cache) + return ERR_PTR(-ENOMEM); + + cache->refcount = 1; + INIT_LIST_HEAD(&cache->entries); + + res = ovl_dir_read_merged(dentry, &cache->entries); + if (res) { + ovl_cache_free(&cache->entries); + kfree(cache); + return ERR_PTR(res); + } + + cache->version = ovl_dentry_version_get(dentry); + ovl_set_dir_cache(dentry, cache); + + return cache; +} + +static int ovl_iterate(struct file *file, struct dir_context *ctx) +{ + struct ovl_dir_file *od = file->private_data; + struct dentry *dentry = file->f_path.dentry; + struct ovl_cache_entry *p; + + if (!ctx->pos) + ovl_dir_reset(file); + + if (od->is_real) + return iterate_dir(od->realfile, ctx); + + if (!od->cache) { + struct ovl_dir_cache *cache; + + cache = ovl_cache_get(dentry); + if (IS_ERR(cache)) + return PTR_ERR(cache); + + od->cache = cache; + ovl_seek_cursor(od, ctx->pos); + } + + while (od->cursor != &od->cache->entries) { + p = list_entry(od->cursor, struct ovl_cache_entry, l_node); + if (!p->is_whiteout) + if (!dir_emit(ctx, p->name, p->len, p->ino, p->type)) + break; + od->cursor = p->l_node.next; + ctx->pos++; + } + return 0; +} + +static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin) +{ + loff_t res; + struct ovl_dir_file *od = file->private_data; + + mutex_lock(&file_inode(file)->i_mutex); + if (!file->f_pos) + ovl_dir_reset(file); + + if (od->is_real) { + res = vfs_llseek(od->realfile, offset, origin); + file->f_pos = od->realfile->f_pos; + } else { + res = -EINVAL; + + switch (origin) { + case SEEK_CUR: + offset += file->f_pos; + break; + case SEEK_SET: + break; + default: + goto out_unlock; + } + if (offset < 0) + goto out_unlock; + + if (offset != file->f_pos) { + file->f_pos = offset; + if (od->cache) + ovl_seek_cursor(od, offset); + } + res = offset; + } +out_unlock: + mutex_unlock(&file_inode(file)->i_mutex); + + return res; +} + +static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end, + int datasync) +{ + struct ovl_dir_file *od = file->private_data; + struct dentry *dentry = file->f_path.dentry; + struct file *realfile = od->realfile; + + /* + * Need to check if we started out being a lower dir, but got copied up + */ + if (!od->is_upper && OVL_TYPE_UPPER(ovl_path_type(dentry))) { + struct inode *inode = file_inode(file); + + realfile = lockless_dereference(od->upperfile); + if (!realfile) { + struct path upperpath; + + ovl_path_upper(dentry, &upperpath); + realfile = ovl_path_open(&upperpath, O_RDONLY); + smp_mb__before_spinlock(); + mutex_lock(&inode->i_mutex); + if (!od->upperfile) { + if (IS_ERR(realfile)) { + mutex_unlock(&inode->i_mutex); + return PTR_ERR(realfile); + } + od->upperfile = realfile; + } else { + /* somebody has beaten us to it */ + if (!IS_ERR(realfile)) + fput(realfile); + realfile = od->upperfile; + } + mutex_unlock(&inode->i_mutex); + } + } + + return vfs_fsync_range(realfile, start, end, datasync); +} + +static int ovl_dir_release(struct inode *inode, struct file *file) +{ + struct ovl_dir_file *od = file->private_data; + + if (od->cache) { + mutex_lock(&inode->i_mutex); + ovl_cache_put(od, file->f_path.dentry); + mutex_unlock(&inode->i_mutex); + } + fput(od->realfile); + if (od->upperfile) + fput(od->upperfile); + kfree(od); + + return 0; +} + +static int ovl_dir_open(struct inode *inode, struct file *file) +{ + struct path realpath; + struct file *realfile; + struct ovl_dir_file *od; + enum ovl_path_type type; + + od = kzalloc(sizeof(struct ovl_dir_file), GFP_KERNEL); + if (!od) + return -ENOMEM; + + type = ovl_path_real(file->f_path.dentry, &realpath); + realfile = ovl_path_open(&realpath, file->f_flags); + if (IS_ERR(realfile)) { + kfree(od); + return PTR_ERR(realfile); + } + od->realfile = realfile; + od->is_real = !OVL_TYPE_MERGE(type); + od->is_upper = OVL_TYPE_UPPER(type); + file->private_data = od; + + return 0; +} + +const struct file_operations ovl_dir_operations = { + .read = generic_read_dir, + .open = ovl_dir_open, + .iterate = ovl_iterate, + .llseek = ovl_dir_llseek, + .fsync = ovl_dir_fsync, + .release = ovl_dir_release, +}; + +int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list) +{ + int err; + struct ovl_cache_entry *p; + + err = ovl_dir_read_merged(dentry, list); + if (err) + return err; + + err = 0; + + list_for_each_entry(p, list, l_node) { + if (p->is_whiteout) + continue; + + if (p->name[0] == '.') { + if (p->len == 1) + continue; + if (p->len == 2 && p->name[1] == '.') + continue; + } + err = -ENOTEMPTY; + break; + } + + return err; +} + +void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list) +{ + struct ovl_cache_entry *p; + + mutex_lock_nested(&upper->d_inode->i_mutex, I_MUTEX_CHILD); + list_for_each_entry(p, list, l_node) { + struct dentry *dentry; + + if (!p->is_whiteout) + continue; + + dentry = lookup_one_len(p->name, upper, p->len); + if (IS_ERR(dentry)) { + pr_err("overlayfs: lookup '%s/%.*s' failed (%i)\n", + upper->d_name.name, p->len, p->name, + (int) PTR_ERR(dentry)); + continue; + } + ovl_cleanup(upper->d_inode, dentry); + dput(dentry); + } + mutex_unlock(&upper->d_inode->i_mutex); +} diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c new file mode 100644 index 000000000000..5f0d1993e6e3 --- /dev/null +++ b/fs/overlayfs/super.c @@ -0,0 +1,1046 @@ +/* + * + * Copyright (C) 2011 Novell Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include <linux/fs.h> +#include <linux/namei.h> +#include <linux/xattr.h> +#include <linux/security.h> +#include <linux/mount.h> +#include <linux/slab.h> +#include <linux/parser.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/statfs.h> +#include <linux/seq_file.h> +#include "overlayfs.h" + +MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); +MODULE_DESCRIPTION("Overlay filesystem"); +MODULE_LICENSE("GPL"); + +#define OVERLAYFS_SUPER_MAGIC 0x794c7630 + +struct ovl_config { + char *lowerdir; + char *upperdir; + char *workdir; +}; + +/* private information held for overlayfs's superblock */ +struct ovl_fs { + struct vfsmount *upper_mnt; + unsigned numlower; + struct vfsmount **lower_mnt; + struct dentry *workdir; + long lower_namelen; + /* pathnames of lower and upper dirs, for show_options */ + struct ovl_config config; +}; + +struct ovl_dir_cache; + +/* private information held for every overlayfs dentry */ +struct ovl_entry { + struct dentry *__upperdentry; + struct ovl_dir_cache *cache; + union { + struct { + u64 version; + bool opaque; + }; + struct rcu_head rcu; + }; + unsigned numlower; + struct path lowerstack[]; +}; + +#define OVL_MAX_STACK 500 + +static struct dentry *__ovl_dentry_lower(struct ovl_entry *oe) +{ + return oe->numlower ? oe->lowerstack[0].dentry : NULL; +} + +enum ovl_path_type ovl_path_type(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + enum ovl_path_type type = 0; + + if (oe->__upperdentry) { + type = __OVL_PATH_UPPER; + + if (oe->numlower) { + if (S_ISDIR(dentry->d_inode->i_mode)) + type |= __OVL_PATH_MERGE; + } else if (!oe->opaque) { + type |= __OVL_PATH_PURE; + } + } else { + if (oe->numlower > 1) + type |= __OVL_PATH_MERGE; + } + return type; +} + +static struct dentry *ovl_upperdentry_dereference(struct ovl_entry *oe) +{ + return lockless_dereference(oe->__upperdentry); +} + +void ovl_path_upper(struct dentry *dentry, struct path *path) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + struct ovl_entry *oe = dentry->d_fsdata; + + path->mnt = ofs->upper_mnt; + path->dentry = ovl_upperdentry_dereference(oe); +} + +enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path) +{ + enum ovl_path_type type = ovl_path_type(dentry); + + if (!OVL_TYPE_UPPER(type)) + ovl_path_lower(dentry, path); + else + ovl_path_upper(dentry, path); + + return type; +} + +struct dentry *ovl_dentry_upper(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + return ovl_upperdentry_dereference(oe); +} + +struct dentry *ovl_dentry_lower(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + return __ovl_dentry_lower(oe); +} + +struct dentry *ovl_dentry_real(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + struct dentry *realdentry; + + realdentry = ovl_upperdentry_dereference(oe); + if (!realdentry) + realdentry = __ovl_dentry_lower(oe); + + return realdentry; +} + +struct dentry *ovl_entry_real(struct ovl_entry *oe, bool *is_upper) +{ + struct dentry *realdentry; + + realdentry = ovl_upperdentry_dereference(oe); + if (realdentry) { + *is_upper = true; + } else { + realdentry = __ovl_dentry_lower(oe); + *is_upper = false; + } + return realdentry; +} + +struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + return oe->cache; +} + +void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + oe->cache = cache; +} + +void ovl_path_lower(struct dentry *dentry, struct path *path) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + *path = oe->numlower ? oe->lowerstack[0] : (struct path) { NULL, NULL }; +} + +int ovl_want_write(struct dentry *dentry) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + return mnt_want_write(ofs->upper_mnt); +} + +void ovl_drop_write(struct dentry *dentry) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + mnt_drop_write(ofs->upper_mnt); +} + +struct dentry *ovl_workdir(struct dentry *dentry) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + return ofs->workdir; +} + +bool ovl_dentry_is_opaque(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + return oe->opaque; +} + +void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque) +{ + struct ovl_entry *oe = dentry->d_fsdata; + oe->opaque = opaque; +} + +void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + WARN_ON(!mutex_is_locked(&upperdentry->d_parent->d_inode->i_mutex)); + WARN_ON(oe->__upperdentry); + BUG_ON(!upperdentry->d_inode); + /* + * Make sure upperdentry is consistent before making it visible to + * ovl_upperdentry_dereference(). + */ + smp_wmb(); + oe->__upperdentry = upperdentry; +} + +void ovl_dentry_version_inc(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + WARN_ON(!mutex_is_locked(&dentry->d_inode->i_mutex)); + oe->version++; +} + +u64 ovl_dentry_version_get(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + WARN_ON(!mutex_is_locked(&dentry->d_inode->i_mutex)); + return oe->version; +} + +bool ovl_is_whiteout(struct dentry *dentry) +{ + struct inode *inode = dentry->d_inode; + + return inode && IS_WHITEOUT(inode); +} + +static bool ovl_is_opaquedir(struct dentry *dentry) +{ + int res; + char val; + struct inode *inode = dentry->d_inode; + + if (!S_ISDIR(inode->i_mode) || !inode->i_op->getxattr) + return false; + + res = inode->i_op->getxattr(dentry, OVL_XATTR_OPAQUE, &val, 1); + if (res == 1 && val == 'y') + return true; + + return false; +} + +static void ovl_dentry_release(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + if (oe) { + unsigned int i; + + dput(oe->__upperdentry); + for (i = 0; i < oe->numlower; i++) + dput(oe->lowerstack[i].dentry); + kfree_rcu(oe, rcu); + } +} + +static const struct dentry_operations ovl_dentry_operations = { + .d_release = ovl_dentry_release, +}; + +static struct ovl_entry *ovl_alloc_entry(unsigned int numlower) +{ + size_t size = offsetof(struct ovl_entry, lowerstack[numlower]); + struct ovl_entry *oe = kzalloc(size, GFP_KERNEL); + + if (oe) + oe->numlower = numlower; + + return oe; +} + +static inline struct dentry *ovl_lookup_real(struct dentry *dir, + struct qstr *name) +{ + struct dentry *dentry; + + mutex_lock(&dir->d_inode->i_mutex); + dentry = lookup_one_len(name->name, dir, name->len); + mutex_unlock(&dir->d_inode->i_mutex); + + if (IS_ERR(dentry)) { + if (PTR_ERR(dentry) == -ENOENT) + dentry = NULL; + } else if (!dentry->d_inode) { + dput(dentry); + dentry = NULL; + } + return dentry; +} + +/* + * Returns next layer in stack starting from top. + * Returns -1 if this is the last layer. + */ +int ovl_path_next(int idx, struct dentry *dentry, struct path *path) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + BUG_ON(idx < 0); + if (idx == 0) { + ovl_path_upper(dentry, path); + if (path->dentry) + return oe->numlower ? 1 : -1; + idx++; + } + BUG_ON(idx > oe->numlower); + *path = oe->lowerstack[idx - 1]; + + return (idx < oe->numlower) ? idx + 1 : -1; +} + +struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, + unsigned int flags) +{ + struct ovl_entry *oe; + struct ovl_entry *poe = dentry->d_parent->d_fsdata; + struct path *stack = NULL; + struct dentry *upperdir, *upperdentry = NULL; + unsigned int ctr = 0; + struct inode *inode = NULL; + bool upperopaque = false; + struct dentry *this, *prev = NULL; + unsigned int i; + int err; + + upperdir = ovl_upperdentry_dereference(poe); + if (upperdir) { + this = ovl_lookup_real(upperdir, &dentry->d_name); + err = PTR_ERR(this); + if (IS_ERR(this)) + goto out; + + if (this) { + if (ovl_is_whiteout(this)) { + dput(this); + this = NULL; + upperopaque = true; + } else if (poe->numlower && ovl_is_opaquedir(this)) { + upperopaque = true; + } + } + upperdentry = prev = this; + } + + if (!upperopaque && poe->numlower) { + err = -ENOMEM; + stack = kcalloc(poe->numlower, sizeof(struct path), GFP_KERNEL); + if (!stack) + goto out_put_upper; + } + + for (i = 0; !upperopaque && i < poe->numlower; i++) { + bool opaque = false; + struct path lowerpath = poe->lowerstack[i]; + + this = ovl_lookup_real(lowerpath.dentry, &dentry->d_name); + err = PTR_ERR(this); + if (IS_ERR(this)) { + /* + * If it's positive, then treat ENAMETOOLONG as ENOENT. + */ + if (err == -ENAMETOOLONG && (upperdentry || ctr)) + continue; + goto out_put; + } + if (!this) + continue; + if (ovl_is_whiteout(this)) { + dput(this); + break; + } + /* + * Only makes sense to check opaque dir if this is not the + * lowermost layer. + */ + if (i < poe->numlower - 1 && ovl_is_opaquedir(this)) + opaque = true; + + if (prev && (!S_ISDIR(prev->d_inode->i_mode) || + !S_ISDIR(this->d_inode->i_mode))) { + /* + * FIXME: check for upper-opaqueness maybe better done + * in remove code. + */ + if (prev == upperdentry) + upperopaque = true; + dput(this); + break; + } + /* + * If this is a non-directory then stop here. + */ + if (!S_ISDIR(this->d_inode->i_mode)) + opaque = true; + + stack[ctr].dentry = this; + stack[ctr].mnt = lowerpath.mnt; + ctr++; + prev = this; + if (opaque) + break; + } + + oe = ovl_alloc_entry(ctr); + err = -ENOMEM; + if (!oe) + goto out_put; + + if (upperdentry || ctr) { + struct dentry *realdentry; + + realdentry = upperdentry ? upperdentry : stack[0].dentry; + + err = -ENOMEM; + inode = ovl_new_inode(dentry->d_sb, realdentry->d_inode->i_mode, + oe); + if (!inode) + goto out_free_oe; + ovl_copyattr(realdentry->d_inode, inode); + } + + oe->opaque = upperopaque; + oe->__upperdentry = upperdentry; + memcpy(oe->lowerstack, stack, sizeof(struct path) * ctr); + kfree(stack); + dentry->d_fsdata = oe; + d_add(dentry, inode); + + return NULL; + +out_free_oe: + kfree(oe); +out_put: + for (i = 0; i < ctr; i++) + dput(stack[i].dentry); + kfree(stack); +out_put_upper: + dput(upperdentry); +out: + return ERR_PTR(err); +} + +struct file *ovl_path_open(struct path *path, int flags) +{ + return dentry_open(path, flags, current_cred()); +} + +static void ovl_put_super(struct super_block *sb) +{ + struct ovl_fs *ufs = sb->s_fs_info; + unsigned i; + + dput(ufs->workdir); + mntput(ufs->upper_mnt); + for (i = 0; i < ufs->numlower; i++) + mntput(ufs->lower_mnt[i]); + + kfree(ufs->config.lowerdir); + kfree(ufs->config.upperdir); + kfree(ufs->config.workdir); + kfree(ufs); +} + +/** + * ovl_statfs + * @sb: The overlayfs super block + * @buf: The struct kstatfs to fill in with stats + * + * Get the filesystem statistics. As writes always target the upper layer + * filesystem pass the statfs to the upper filesystem (if it exists) + */ +static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + struct dentry *root_dentry = dentry->d_sb->s_root; + struct path path; + int err; + + ovl_path_real(root_dentry, &path); + + err = vfs_statfs(&path, buf); + if (!err) { + buf->f_namelen = max(buf->f_namelen, ofs->lower_namelen); + buf->f_type = OVERLAYFS_SUPER_MAGIC; + } + + return err; +} + +/** + * ovl_show_options + * + * Prints the mount options for a given superblock. + * Returns zero; does not fail. + */ +static int ovl_show_options(struct seq_file *m, struct dentry *dentry) +{ + struct super_block *sb = dentry->d_sb; + struct ovl_fs *ufs = sb->s_fs_info; + + seq_printf(m, ",lowerdir=%s", ufs->config.lowerdir); + if (ufs->config.upperdir) { + seq_printf(m, ",upperdir=%s", ufs->config.upperdir); + seq_printf(m, ",workdir=%s", ufs->config.workdir); + } + return 0; +} + +static int ovl_remount(struct super_block *sb, int *flags, char *data) +{ + struct ovl_fs *ufs = sb->s_fs_info; + + if (!(*flags & MS_RDONLY) && !ufs->upper_mnt) + return -EROFS; + + return 0; +} + +static const struct super_operations ovl_super_operations = { + .put_super = ovl_put_super, + .statfs = ovl_statfs, + .show_options = ovl_show_options, + .remount_fs = ovl_remount, +}; + +enum { + OPT_LOWERDIR, + OPT_UPPERDIR, + OPT_WORKDIR, + OPT_ERR, +}; + +static const match_table_t ovl_tokens = { + {OPT_LOWERDIR, "lowerdir=%s"}, + {OPT_UPPERDIR, "upperdir=%s"}, + {OPT_WORKDIR, "workdir=%s"}, + {OPT_ERR, NULL} +}; + +static char *ovl_next_opt(char **s) +{ + char *sbegin = *s; + char *p; + + if (sbegin == NULL) + return NULL; + + for (p = sbegin; *p; p++) { + if (*p == '\\') { + p++; + if (!*p) + break; + } else if (*p == ',') { + *p = '\0'; + *s = p + 1; + return sbegin; + } + } + *s = NULL; + return sbegin; +} + +static int ovl_parse_opt(char *opt, struct ovl_config *config) +{ + char *p; + + while ((p = ovl_next_opt(&opt)) != NULL) { + int token; + substring_t args[MAX_OPT_ARGS]; + + if (!*p) + continue; + + token = match_token(p, ovl_tokens, args); + switch (token) { + case OPT_UPPERDIR: + kfree(config->upperdir); + config->upperdir = match_strdup(&args[0]); + if (!config->upperdir) + return -ENOMEM; + break; + + case OPT_LOWERDIR: + kfree(config->lowerdir); + config->lowerdir = match_strdup(&args[0]); + if (!config->lowerdir) + return -ENOMEM; + break; + + case OPT_WORKDIR: + kfree(config->workdir); + config->workdir = match_strdup(&args[0]); + if (!config->workdir) + return -ENOMEM; + break; + + default: + pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p); + return -EINVAL; + } + } + + /* Workdir is useless in non-upper mount */ + if (!config->upperdir && config->workdir) { + pr_info("overlayfs: option \"workdir=%s\" is useless in a non-upper mount, ignore\n", + config->workdir); + kfree(config->workdir); + config->workdir = NULL; + } + + return 0; +} + +#define OVL_WORKDIR_NAME "work" + +static struct dentry *ovl_workdir_create(struct vfsmount *mnt, + struct dentry *dentry) +{ + struct inode *dir = dentry->d_inode; + struct dentry *work; + int err; + bool retried = false; + + err = mnt_want_write(mnt); + if (err) + return ERR_PTR(err); + + mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); +retry: + work = lookup_one_len(OVL_WORKDIR_NAME, dentry, + strlen(OVL_WORKDIR_NAME)); + + if (!IS_ERR(work)) { + struct kstat stat = { + .mode = S_IFDIR | 0, + }; + + if (work->d_inode) { + err = -EEXIST; + if (retried) + goto out_dput; + + retried = true; + ovl_cleanup(dir, work); + dput(work); + goto retry; + } + + err = ovl_create_real(dir, work, &stat, NULL, NULL, true); + if (err) + goto out_dput; + } +out_unlock: + mutex_unlock(&dir->i_mutex); + mnt_drop_write(mnt); + + return work; + +out_dput: + dput(work); + work = ERR_PTR(err); + goto out_unlock; +} + +static void ovl_unescape(char *s) +{ + char *d = s; + + for (;; s++, d++) { + if (*s == '\\') + s++; + *d = *s; + if (!*s) + break; + } +} + +static bool ovl_is_allowed_fs_type(struct dentry *root) +{ + const struct dentry_operations *dop = root->d_op; + + /* + * We don't support: + * - automount filesystems + * - filesystems with revalidate (FIXME for lower layer) + * - filesystems with case insensitive names + */ + if (dop && + (dop->d_manage || dop->d_automount || + dop->d_revalidate || dop->d_weak_revalidate || + dop->d_compare || dop->d_hash)) { + return false; + } + return true; +} + +static int ovl_mount_dir_noesc(const char *name, struct path *path) +{ + int err = -EINVAL; + + if (!*name) { + pr_err("overlayfs: empty lowerdir\n"); + goto out; + } + err = kern_path(name, LOOKUP_FOLLOW, path); + if (err) { + pr_err("overlayfs: failed to resolve '%s': %i\n", name, err); + goto out; + } + err = -EINVAL; + if (!ovl_is_allowed_fs_type(path->dentry)) { + pr_err("overlayfs: filesystem on '%s' not supported\n", name); + goto out_put; + } + if (!S_ISDIR(path->dentry->d_inode->i_mode)) { + pr_err("overlayfs: '%s' not a directory\n", name); + goto out_put; + } + return 0; + +out_put: + path_put(path); +out: + return err; +} + +static int ovl_mount_dir(const char *name, struct path *path) +{ + int err = -ENOMEM; + char *tmp = kstrdup(name, GFP_KERNEL); + + if (tmp) { + ovl_unescape(tmp); + err = ovl_mount_dir_noesc(tmp, path); + kfree(tmp); + } + return err; +} + +static int ovl_lower_dir(const char *name, struct path *path, long *namelen, + int *stack_depth) +{ + int err; + struct kstatfs statfs; + + err = ovl_mount_dir_noesc(name, path); + if (err) + goto out; + + err = vfs_statfs(path, &statfs); + if (err) { + pr_err("overlayfs: statfs failed on '%s'\n", name); + goto out_put; + } + *namelen = max(*namelen, statfs.f_namelen); + *stack_depth = max(*stack_depth, path->mnt->mnt_sb->s_stack_depth); + + return 0; + +out_put: + path_put(path); +out: + return err; +} + +/* Workdir should not be subdir of upperdir and vice versa */ +static bool ovl_workdir_ok(struct dentry *workdir, struct dentry *upperdir) +{ + bool ok = false; + + if (workdir != upperdir) { + ok = (lock_rename(workdir, upperdir) == NULL); + unlock_rename(workdir, upperdir); + } + return ok; +} + +static unsigned int ovl_split_lowerdirs(char *str) +{ + unsigned int ctr = 1; + char *s, *d; + + for (s = d = str;; s++, d++) { + if (*s == '\\') { + s++; + } else if (*s == ':') { + *d = '\0'; + ctr++; + continue; + } + *d = *s; + if (!*s) + break; + } + return ctr; +} + +static int ovl_fill_super(struct super_block *sb, void *data, int silent) +{ + struct path upperpath = { NULL, NULL }; + struct path workpath = { NULL, NULL }; + struct dentry *root_dentry; + struct ovl_entry *oe; + struct ovl_fs *ufs; + struct path *stack = NULL; + char *lowertmp; + char *lower; + unsigned int numlower; + unsigned int stacklen = 0; + unsigned int i; + int err; + + err = -ENOMEM; + ufs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL); + if (!ufs) + goto out; + + err = ovl_parse_opt((char *) data, &ufs->config); + if (err) + goto out_free_config; + + err = -EINVAL; + if (!ufs->config.lowerdir) { + pr_err("overlayfs: missing 'lowerdir'\n"); + goto out_free_config; + } + + sb->s_stack_depth = 0; + if (ufs->config.upperdir) { + if (!ufs->config.workdir) { + pr_err("overlayfs: missing 'workdir'\n"); + goto out_free_config; + } + + err = ovl_mount_dir(ufs->config.upperdir, &upperpath); + if (err) + goto out_free_config; + + /* Upper fs should not be r/o */ + if (upperpath.mnt->mnt_sb->s_flags & MS_RDONLY) { + pr_err("overlayfs: upper fs is r/o, try multi-lower layers mount\n"); + err = -EINVAL; + goto out_put_upperpath; + } + + err = ovl_mount_dir(ufs->config.workdir, &workpath); + if (err) + goto out_put_upperpath; + + err = -EINVAL; + if (upperpath.mnt != workpath.mnt) { + pr_err("overlayfs: workdir and upperdir must reside under the same mount\n"); + goto out_put_workpath; + } + if (!ovl_workdir_ok(workpath.dentry, upperpath.dentry)) { + pr_err("overlayfs: workdir and upperdir must be separate subtrees\n"); + goto out_put_workpath; + } + sb->s_stack_depth = upperpath.mnt->mnt_sb->s_stack_depth; + } + err = -ENOMEM; + lowertmp = kstrdup(ufs->config.lowerdir, GFP_KERNEL); + if (!lowertmp) + goto out_put_workpath; + + err = -EINVAL; + stacklen = ovl_split_lowerdirs(lowertmp); + if (stacklen > OVL_MAX_STACK) { + pr_err("overlayfs: too many lower directries, limit is %d\n", + OVL_MAX_STACK); + goto out_free_lowertmp; + } else if (!ufs->config.upperdir && stacklen == 1) { + pr_err("overlayfs: at least 2 lowerdir are needed while upperdir nonexistent\n"); + goto out_free_lowertmp; + } + + stack = kcalloc(stacklen, sizeof(struct path), GFP_KERNEL); + if (!stack) + goto out_free_lowertmp; + + lower = lowertmp; + for (numlower = 0; numlower < stacklen; numlower++) { + err = ovl_lower_dir(lower, &stack[numlower], + &ufs->lower_namelen, &sb->s_stack_depth); + if (err) + goto out_put_lowerpath; + + lower = strchr(lower, '\0') + 1; + } + + err = -EINVAL; + sb->s_stack_depth++; + if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { + pr_err("overlayfs: maximum fs stacking depth exceeded\n"); + goto out_put_lowerpath; + } + + if (ufs->config.upperdir) { + ufs->upper_mnt = clone_private_mount(&upperpath); + err = PTR_ERR(ufs->upper_mnt); + if (IS_ERR(ufs->upper_mnt)) { + pr_err("overlayfs: failed to clone upperpath\n"); + goto out_put_lowerpath; + } + + ufs->workdir = ovl_workdir_create(ufs->upper_mnt, workpath.dentry); + err = PTR_ERR(ufs->workdir); + if (IS_ERR(ufs->workdir)) { + pr_err("overlayfs: failed to create directory %s/%s\n", + ufs->config.workdir, OVL_WORKDIR_NAME); + goto out_put_upper_mnt; + } + } + + err = -ENOMEM; + ufs->lower_mnt = kcalloc(numlower, sizeof(struct vfsmount *), GFP_KERNEL); + if (ufs->lower_mnt == NULL) + goto out_put_workdir; + for (i = 0; i < numlower; i++) { + struct vfsmount *mnt = clone_private_mount(&stack[i]); + + err = PTR_ERR(mnt); + if (IS_ERR(mnt)) { + pr_err("overlayfs: failed to clone lowerpath\n"); + goto out_put_lower_mnt; + } + /* + * Make lower_mnt R/O. That way fchmod/fchown on lower file + * will fail instead of modifying lower fs. + */ + mnt->mnt_flags |= MNT_READONLY; + + ufs->lower_mnt[ufs->numlower] = mnt; + ufs->numlower++; + } + + /* If the upper fs is nonexistent, we mark overlayfs r/o too */ + if (!ufs->upper_mnt) + sb->s_flags |= MS_RDONLY; + + sb->s_d_op = &ovl_dentry_operations; + + err = -ENOMEM; + oe = ovl_alloc_entry(numlower); + if (!oe) + goto out_put_lower_mnt; + + root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR, oe)); + if (!root_dentry) + goto out_free_oe; + + mntput(upperpath.mnt); + for (i = 0; i < numlower; i++) + mntput(stack[i].mnt); + path_put(&workpath); + kfree(lowertmp); + + oe->__upperdentry = upperpath.dentry; + for (i = 0; i < numlower; i++) { + oe->lowerstack[i].dentry = stack[i].dentry; + oe->lowerstack[i].mnt = ufs->lower_mnt[i]; + } + + root_dentry->d_fsdata = oe; + + sb->s_magic = OVERLAYFS_SUPER_MAGIC; + sb->s_op = &ovl_super_operations; + sb->s_root = root_dentry; + sb->s_fs_info = ufs; + + return 0; + +out_free_oe: + kfree(oe); +out_put_lower_mnt: + for (i = 0; i < ufs->numlower; i++) + mntput(ufs->lower_mnt[i]); + kfree(ufs->lower_mnt); +out_put_workdir: + dput(ufs->workdir); +out_put_upper_mnt: + mntput(ufs->upper_mnt); +out_put_lowerpath: + for (i = 0; i < numlower; i++) + path_put(&stack[i]); + kfree(stack); +out_free_lowertmp: + kfree(lowertmp); +out_put_workpath: + path_put(&workpath); +out_put_upperpath: + path_put(&upperpath); +out_free_config: + kfree(ufs->config.lowerdir); + kfree(ufs->config.upperdir); + kfree(ufs->config.workdir); + kfree(ufs); +out: + return err; +} + +static struct dentry *ovl_mount(struct file_system_type *fs_type, int flags, + const char *dev_name, void *raw_data) +{ + return mount_nodev(fs_type, flags, raw_data, ovl_fill_super); +} + +static struct file_system_type ovl_fs_type = { + .owner = THIS_MODULE, + .name = "overlay", + .mount = ovl_mount, + .kill_sb = kill_anon_super, +}; +MODULE_ALIAS_FS("overlay"); + +static int __init ovl_init(void) +{ + return register_filesystem(&ovl_fs_type); +} + +static void __exit ovl_exit(void) +{ + unregister_filesystem(&ovl_fs_type); +} + +module_init(ovl_init); +module_exit(ovl_exit); diff --git a/fs/proc/Makefile b/fs/proc/Makefile index ab30716584f5..239493ec718e 100644 --- a/fs/proc/Makefile +++ b/fs/proc/Makefile @@ -27,6 +27,5 @@ proc-$(CONFIG_PROC_SYSCTL) += proc_sysctl.o proc-$(CONFIG_NET) += proc_net.o proc-$(CONFIG_PROC_KCORE) += kcore.o proc-$(CONFIG_PROC_VMCORE) += vmcore.o -proc-$(CONFIG_PROC_DEVICETREE) += proc_devtree.o proc-$(CONFIG_PRINTK) += kmsg.o proc-$(CONFIG_PROC_PAGE_MONITOR) += page.o diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 8b8ca1db6316..8b24f3640cd9 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -212,13 +212,6 @@ extern int proc_fill_super(struct super_block *); extern void proc_entry_rundown(struct proc_dir_entry *); /* - * proc_devtree.c - */ -#ifdef CONFIG_PROC_DEVICETREE -extern void proc_device_tree_init(void); -#endif - -/* * proc_namespaces.c */ extern const struct inode_operations proc_ns_dir_inode_operations; diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c index 9ae46b87470d..89026095f2b5 100644 --- a/fs/proc/namespaces.c +++ b/fs/proc/namespaces.c @@ -146,7 +146,7 @@ static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int bufl struct task_struct *task; void *ns; char name[50]; - int len = -EACCES; + int res = -EACCES; task = get_proc_task(inode); if (!task) @@ -155,24 +155,18 @@ static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int bufl if (!ptrace_may_access(task, PTRACE_MODE_READ)) goto out_put_task; - len = -ENOENT; + res = -ENOENT; ns = ns_ops->get(task); if (!ns) goto out_put_task; snprintf(name, sizeof(name), "%s:[%u]", ns_ops->name, ns_ops->inum(ns)); - len = strlen(name); - - if (len > buflen) - len = buflen; - if (copy_to_user(buffer, name, len)) - len = -EFAULT; - + res = readlink_copy(buffer, buflen, name); ns_ops->put(ns); out_put_task: put_task_struct(task); out: - return len; + return res; } static const struct inode_operations proc_ns_link_inode_operations = { diff --git a/fs/proc/proc_devtree.c b/fs/proc/proc_devtree.c deleted file mode 100644 index c82dd5147845..000000000000 --- a/fs/proc/proc_devtree.c +++ /dev/null @@ -1,241 +0,0 @@ -/* - * proc_devtree.c - handles /proc/device-tree - * - * Copyright 1997 Paul Mackerras - */ -#include <linux/errno.h> -#include <linux/init.h> -#include <linux/time.h> -#include <linux/proc_fs.h> -#include <linux/seq_file.h> -#include <linux/printk.h> -#include <linux/stat.h> -#include <linux/string.h> -#include <linux/of.h> -#include <linux/export.h> -#include <linux/slab.h> -#include <asm/uaccess.h> -#include "internal.h" - -static inline void set_node_proc_entry(struct device_node *np, - struct proc_dir_entry *de) -{ - np->pde = de; -} - -static struct proc_dir_entry *proc_device_tree; - -/* - * Supply data on a read from /proc/device-tree/node/property. - */ -static int property_proc_show(struct seq_file *m, void *v) -{ - struct property *pp = m->private; - - seq_write(m, pp->value, pp->length); - return 0; -} - -static int property_proc_open(struct inode *inode, struct file *file) -{ - return single_open(file, property_proc_show, __PDE_DATA(inode)); -} - -static const struct file_operations property_proc_fops = { - .owner = THIS_MODULE, - .open = property_proc_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; - -/* - * For a node with a name like "gc@10", we make symlinks called "gc" - * and "@10" to it. - */ - -/* - * Add a property to a node - */ -static struct proc_dir_entry * -__proc_device_tree_add_prop(struct proc_dir_entry *de, struct property *pp, - const char *name) -{ - struct proc_dir_entry *ent; - - /* - * Unfortunately proc_register puts each new entry - * at the beginning of the list. So we rearrange them. - */ - ent = proc_create_data(name, - strncmp(name, "security-", 9) ? S_IRUGO : S_IRUSR, - de, &property_proc_fops, pp); - if (ent == NULL) - return NULL; - - if (!strncmp(name, "security-", 9)) - proc_set_size(ent, 0); /* don't leak number of password chars */ - else - proc_set_size(ent, pp->length); - - return ent; -} - - -void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop) -{ - __proc_device_tree_add_prop(pde, prop, prop->name); -} - -void proc_device_tree_remove_prop(struct proc_dir_entry *pde, - struct property *prop) -{ - remove_proc_entry(prop->name, pde); -} - -void proc_device_tree_update_prop(struct proc_dir_entry *pde, - struct property *newprop, - struct property *oldprop) -{ - struct proc_dir_entry *ent; - - if (!oldprop) { - proc_device_tree_add_prop(pde, newprop); - return; - } - - for (ent = pde->subdir; ent != NULL; ent = ent->next) - if (ent->data == oldprop) - break; - if (ent == NULL) { - pr_warn("device-tree: property \"%s\" does not exist\n", - oldprop->name); - } else { - ent->data = newprop; - ent->size = newprop->length; - } -} - -/* - * Various dodgy firmware might give us nodes and/or properties with - * conflicting names. That's generally ok, except for exporting via /proc, - * so munge names here to ensure they're unique. - */ - -static int duplicate_name(struct proc_dir_entry *de, const char *name) -{ - struct proc_dir_entry *ent; - int found = 0; - - spin_lock(&proc_subdir_lock); - - for (ent = de->subdir; ent != NULL; ent = ent->next) { - if (strcmp(ent->name, name) == 0) { - found = 1; - break; - } - } - - spin_unlock(&proc_subdir_lock); - - return found; -} - -static const char *fixup_name(struct device_node *np, struct proc_dir_entry *de, - const char *name) -{ - char *fixed_name; - int fixup_len = strlen(name) + 2 + 1; /* name + #x + \0 */ - int i = 1, size; - -realloc: - fixed_name = kmalloc(fixup_len, GFP_KERNEL); - if (fixed_name == NULL) { - pr_err("device-tree: Out of memory trying to fixup " - "name \"%s\"\n", name); - return name; - } - -retry: - size = snprintf(fixed_name, fixup_len, "%s#%d", name, i); - size++; /* account for NULL */ - - if (size > fixup_len) { - /* We ran out of space, free and reallocate. */ - kfree(fixed_name); - fixup_len = size; - goto realloc; - } - - if (duplicate_name(de, fixed_name)) { - /* Multiple duplicates. Retry with a different offset. */ - i++; - goto retry; - } - - pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n", - np->full_name, fixed_name); - - return fixed_name; -} - -/* - * Process a node, adding entries for its children and its properties. - */ -void proc_device_tree_add_node(struct device_node *np, - struct proc_dir_entry *de) -{ - struct property *pp; - struct proc_dir_entry *ent; - struct device_node *child; - const char *p; - - set_node_proc_entry(np, de); - for (child = NULL; (child = of_get_next_child(np, child));) { - /* Use everything after the last slash, or the full name */ - p = kbasename(child->full_name); - - if (duplicate_name(de, p)) - p = fixup_name(np, de, p); - - ent = proc_mkdir(p, de); - if (ent == NULL) - break; - proc_device_tree_add_node(child, ent); - } - of_node_put(child); - - for (pp = np->properties; pp != NULL; pp = pp->next) { - p = pp->name; - - if (strchr(p, '/')) - continue; - - if (duplicate_name(de, p)) - p = fixup_name(np, de, p); - - ent = __proc_device_tree_add_prop(de, pp, p); - if (ent == NULL) - break; - } -} - -/* - * Called on initialization to set up the /proc/device-tree subtree - */ -void __init proc_device_tree_init(void) -{ - struct device_node *root; - - proc_device_tree = proc_mkdir("device-tree", NULL); - if (proc_device_tree == NULL) - return; - root = of_find_node_by_path("/"); - if (root == NULL) { - remove_proc_entry("device-tree", NULL); - pr_debug("/proc/device-tree: can't find root\n"); - return; - } - proc_device_tree_add_node(root, proc_device_tree); - of_node_put(root); -} diff --git a/fs/proc/root.c b/fs/proc/root.c index 87dbcbef7fe4..7bbeb5257af1 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -183,9 +183,6 @@ void __init proc_root_init(void) proc_mkdir("openprom", NULL); #endif proc_tty_init(); -#ifdef CONFIG_PROC_DEVICETREE - proc_device_tree_init(); -#endif proc_mkdir("bus", NULL); proc_sys_init(); } diff --git a/fs/proc/self.c b/fs/proc/self.c index ffeb202ec942..4348bb8907c2 100644 --- a/fs/proc/self.c +++ b/fs/proc/self.c @@ -16,7 +16,7 @@ static int proc_self_readlink(struct dentry *dentry, char __user *buffer, if (!tgid) return -ENOENT; sprintf(tmp, "%d", tgid); - return vfs_readlink(dentry,buffer,buflen,tmp); + return readlink_copy(buffer, buflen, tmp); } static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) diff --git a/fs/readdir.c b/fs/readdir.c index 5b53d995cae6..e21af53ec24e 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -72,10 +72,11 @@ struct readdir_callback { int result; }; -static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset, - u64 ino, unsigned int d_type) +static int fillonedir(struct dir_context *ctx, const char *name, int namlen, + loff_t offset, u64 ino, unsigned int d_type) { - struct readdir_callback *buf = (struct readdir_callback *) __buf; + struct readdir_callback *buf = + container_of(ctx, struct readdir_callback, ctx); struct old_linux_dirent __user * dirent; unsigned long d_ino; @@ -146,11 +147,12 @@ struct getdents_callback { int error; }; -static int filldir(void * __buf, const char * name, int namlen, loff_t offset, - u64 ino, unsigned int d_type) +static int filldir(struct dir_context *ctx, const char *name, int namlen, + loff_t offset, u64 ino, unsigned int d_type) { struct linux_dirent __user * dirent; - struct getdents_callback * buf = (struct getdents_callback *) __buf; + struct getdents_callback *buf = + container_of(ctx, struct getdents_callback, ctx); unsigned long d_ino; int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2, sizeof(long)); @@ -230,11 +232,12 @@ struct getdents_callback64 { int error; }; -static int filldir64(void * __buf, const char * name, int namlen, loff_t offset, - u64 ino, unsigned int d_type) +static int filldir64(struct dir_context *ctx, const char *name, int namlen, + loff_t offset, u64 ino, unsigned int d_type) { struct linux_dirent64 __user *dirent; - struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf; + struct getdents_callback64 *buf = + container_of(ctx, struct getdents_callback64, ctx); int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1, sizeof(u64)); diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c index 5cdfbd638b5c..d8b7acfd5066 100644 --- a/fs/reiserfs/xattr.c +++ b/fs/reiserfs/xattr.c @@ -177,10 +177,11 @@ struct reiserfs_dentry_buf { }; static int -fill_with_dentries(void *buf, const char *name, int namelen, loff_t offset, - u64 ino, unsigned int d_type) +fill_with_dentries(struct dir_context *ctx, const char *name, int namelen, + loff_t offset, u64 ino, unsigned int d_type) { - struct reiserfs_dentry_buf *dbuf = buf; + struct reiserfs_dentry_buf *dbuf = + container_of(ctx, struct reiserfs_dentry_buf, ctx); struct dentry *dentry; WARN_ON_ONCE(!mutex_is_locked(&dbuf->xadir->d_inode->i_mutex)); @@ -794,10 +795,12 @@ struct listxattr_buf { struct dentry *dentry; }; -static int listxattr_filler(void *buf, const char *name, int namelen, - loff_t offset, u64 ino, unsigned int d_type) +static int listxattr_filler(struct dir_context *ctx, const char *name, + int namelen, loff_t offset, u64 ino, + unsigned int d_type) { - struct listxattr_buf *b = (struct listxattr_buf *)buf; + struct listxattr_buf *b = + container_of(ctx, struct listxattr_buf, ctx); size_t size; if (name[0] != '.' || (namelen != 1 && (name[1] != '.' || namelen != 2))) { diff --git a/fs/splice.c b/fs/splice.c index 12028fa41def..ffb92b9d34ba 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -1327,6 +1327,7 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, return ret; } +EXPORT_SYMBOL(do_splice_direct); static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe, struct pipe_inode_info *opipe, diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index 78e62cc471c5..6152cbe353e8 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -271,32 +271,6 @@ xfs_open_by_handle( return error; } -/* - * This is a copy from fs/namei.c:vfs_readlink(), except for removing it's - * unused first argument. - */ -STATIC int -do_readlink( - char __user *buffer, - int buflen, - const char *link) -{ - int len; - - len = PTR_ERR(link); - if (IS_ERR(link)) - goto out; - - len = strlen(link); - if (len > (unsigned) buflen) - len = buflen; - if (copy_to_user(buffer, link, len)) - len = -EFAULT; - out: - return len; -} - - int xfs_readlink_by_handle( struct file *parfilp, @@ -334,7 +308,7 @@ xfs_readlink_by_handle( error = -xfs_readlink(XFS_I(dentry->d_inode), link); if (error) goto out_kfree; - error = do_readlink(hreq->ohandle, olen, link); + error = readlink_copy(hreq->ohandle, olen, link); if (error) goto out_kfree; |