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authorLinus Torvalds <torvalds@linux-foundation.org>2014-04-04 15:34:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-04 15:34:27 -0700
commitd15fee814d8d30bbb4859ef8fef7a1f96327635b (patch)
tree1168811b0b28ec6fb9ccb65476019323e5ba9035
parent56c225fe399c27c1f1a098048903f8e74f4ec45f (diff)
parentf3846266f593595632a07242fcbc6c24bc2ade68 (diff)
downloadlinux-linaro-stable-d15fee814d8d30bbb4859ef8fef7a1f96327635b.tar.gz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse update from Miklos Szeredi: "This series adds cached writeback support to fuse, improving write throughput" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: fix "uninitialized variable" warning fuse: Turn writeback cache on fuse: Fix O_DIRECT operations vs cached writeback misorder fuse: fuse_flush() should wait on writeback fuse: Implement write_begin/write_end callbacks fuse: restructure fuse_readpage() fuse: Flush files on wb close fuse: Trust kernel i_mtime only fuse: Trust kernel i_size only fuse: Connection bit for enabling writeback fuse: Prepare to handle short reads fuse: Linking file to inode helper
-rw-r--r--fs/fuse/cuse.c5
-rw-r--r--fs/fuse/dir.c119
-rw-r--r--fs/fuse/file.c286
-rw-r--r--fs/fuse/fuse_i.h22
-rw-r--r--fs/fuse/inode.c29
-rw-r--r--include/uapi/linux/fuse.h7
6 files changed, 384 insertions, 84 deletions
diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c
index b96a49b37d66..23e363f38302 100644
--- a/fs/fuse/cuse.c
+++ b/fs/fuse/cuse.c
@@ -95,7 +95,7 @@ static ssize_t cuse_read(struct file *file, char __user *buf, size_t count,
struct iovec iov = { .iov_base = buf, .iov_len = count };
struct fuse_io_priv io = { .async = 0, .file = file };
- return fuse_direct_io(&io, &iov, 1, count, &pos, 0);
+ return fuse_direct_io(&io, &iov, 1, count, &pos, FUSE_DIO_CUSE);
}
static ssize_t cuse_write(struct file *file, const char __user *buf,
@@ -109,7 +109,8 @@ static ssize_t cuse_write(struct file *file, const char __user *buf,
* No locking or generic_write_checks(), the server is
* responsible for locking and sanity checks.
*/
- return fuse_direct_io(&io, &iov, 1, count, &pos, 1);
+ return fuse_direct_io(&io, &iov, 1, count, &pos,
+ FUSE_DIO_WRITE | FUSE_DIO_CUSE);
}
static int cuse_open(struct inode *inode, struct file *file)
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 1d1292c581c3..5b4e035b364c 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -839,6 +839,14 @@ 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;
+ }
stat->dev = inode->i_sb->s_dev;
stat->ino = attr->ino;
@@ -1477,12 +1485,16 @@ 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;
@@ -1491,7 +1503,8 @@ 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;
@@ -1510,11 +1523,11 @@ 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;
}
}
@@ -1563,6 +1576,63 @@ 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.
*
@@ -1580,8 +1650,10 @@ 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;
@@ -1610,7 +1682,7 @@ 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;
@@ -1621,17 +1693,7 @@ 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);
@@ -1648,10 +1710,18 @@ 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 */
@@ -1663,7 +1733,8 @@ 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);
}
@@ -1875,6 +1946,17 @@ static int fuse_removexattr(struct dentry *entry, const char *name)
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,
@@ -1914,6 +1996,7 @@ 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 77bcc303c3ae..65df7d8be4f5 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;
@@ -208,6 +224,8 @@ void fuse_finish_open(struct inode *inode, struct file *file)
spin_unlock(&fc->lock);
fuse_invalidate_attr(inode);
}
+ if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache)
+ fuse_link_write_file(file);
}
int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
@@ -292,6 +310,15 @@ static int fuse_open(struct inode *inode, struct file *file)
static int fuse_release(struct inode *inode, struct file *file)
{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+
+ /* see fuse_vma_close() for !writeback_cache case */
+ if (fc->writeback_cache)
+ filemap_write_and_wait(file->f_mapping);
+
+ 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 */
@@ -333,12 +360,13 @@ u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
}
/*
- * Check if page is under writeback
+ * Check if any page in a range is under writeback
*
* This is currently done by walking the list of writepage requests
* for the inode, which can be pretty inefficient.
*/
-static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
+static bool fuse_range_is_writeback(struct inode *inode, pgoff_t idx_from,
+ pgoff_t idx_to)
{
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_inode *fi = get_fuse_inode(inode);
@@ -351,8 +379,8 @@ static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
BUG_ON(req->inode != inode);
curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
- if (curr_index <= index &&
- index < curr_index + req->num_pages) {
+ if (idx_from < curr_index + req->num_pages &&
+ curr_index <= idx_to) {
found = true;
break;
}
@@ -362,6 +390,11 @@ static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
return found;
}
+static inline bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
+{
+ return fuse_range_is_writeback(inode, index, index);
+}
+
/*
* Wait for page writeback to be completed.
*
@@ -376,6 +409,21 @@ static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
return 0;
}
+/*
+ * Wait for all pending writepages on the inode to finish.
+ *
+ * This is currently done by blocking further writes with FUSE_NOWRITE
+ * and waiting for all sent writes to complete.
+ *
+ * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
+ * could conflict with truncation.
+ */
+static void fuse_sync_writes(struct inode *inode)
+{
+ fuse_set_nowrite(inode);
+ fuse_release_nowrite(inode);
+}
+
static int fuse_flush(struct file *file, fl_owner_t id)
{
struct inode *inode = file_inode(file);
@@ -391,6 +439,14 @@ static int fuse_flush(struct file *file, fl_owner_t id)
if (fc->no_flush)
return 0;
+ err = filemap_write_and_wait(file->f_mapping);
+ if (err)
+ return err;
+
+ mutex_lock(&inode->i_mutex);
+ fuse_sync_writes(inode);
+ mutex_unlock(&inode->i_mutex);
+
req = fuse_get_req_nofail_nopages(fc, file);
memset(&inarg, 0, sizeof(inarg));
inarg.fh = ff->fh;
@@ -411,21 +467,6 @@ static int fuse_flush(struct file *file, fl_owner_t id)
return err;
}
-/*
- * Wait for all pending writepages on the inode to finish.
- *
- * This is currently done by blocking further writes with FUSE_NOWRITE
- * and waiting for all sent writes to complete.
- *
- * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
- * could conflict with truncation.
- */
-static void fuse_sync_writes(struct inode *inode)
-{
- fuse_set_nowrite(inode);
- fuse_release_nowrite(inode);
-}
-
int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
int datasync, int isdir)
{
@@ -459,6 +500,12 @@ 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);
@@ -655,7 +702,33 @@ static void fuse_read_update_size(struct inode *inode, loff_t size,
spin_unlock(&fc->lock);
}
-static int fuse_readpage(struct file *file, struct page *page)
+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_do_readpage(struct file *file, struct page *page)
{
struct fuse_io_priv io = { .async = 0, .file = file };
struct inode *inode = page->mapping->host;
@@ -667,10 +740,6 @@ static int fuse_readpage(struct file *file, struct page *page)
u64 attr_ver;
int err;
- err = -EIO;
- if (is_bad_inode(inode))
- goto out;
-
/*
* Page writeback can extend beyond the lifetime of the
* page-cache page, so make sure we read a properly synced
@@ -679,9 +748,8 @@ static int fuse_readpage(struct file *file, struct page *page)
fuse_wait_on_page_writeback(inode, page->index);
req = fuse_get_req(fc, 1);
- err = PTR_ERR(req);
if (IS_ERR(req))
- goto out;
+ return PTR_ERR(req);
attr_ver = fuse_get_attr_version(fc);
@@ -692,18 +760,32 @@ 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);
+
+ return err;
+}
+
+static int fuse_readpage(struct file *file, struct page *page)
+{
+ struct inode *inode = page->mapping->host;
+ int err;
+
+ err = -EIO;
+ if (is_bad_inode(inode))
+ goto out;
+
+ err = fuse_do_readpage(file, page);
fuse_invalidate_atime(inode);
out:
unlock_page(page);
@@ -726,13 +808,9 @@ 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 +1000,21 @@ 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,
@@ -1116,6 +1199,15 @@ static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
struct iov_iter i;
loff_t endbyte = 0;
+ if (get_fuse_conn(inode)->writeback_cache) {
+ /* Update size (EOF optimization) and mode (SUID clearing) */
+ err = fuse_update_attributes(mapping->host, NULL, file, NULL);
+ if (err)
+ return err;
+
+ return generic_file_aio_write(iocb, iov, nr_segs, pos);
+ }
+
WARN_ON(iocb->ki_pos != pos);
ocount = 0;
@@ -1289,13 +1381,18 @@ static inline int fuse_iter_npages(const struct iov_iter *ii_p)
ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,
unsigned long nr_segs, size_t count, loff_t *ppos,
- int write)
+ int flags)
{
+ int write = flags & FUSE_DIO_WRITE;
+ int cuse = flags & FUSE_DIO_CUSE;
struct file *file = io->file;
+ struct inode *inode = file->f_mapping->host;
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = ff->fc;
size_t nmax = write ? fc->max_write : fc->max_read;
loff_t pos = *ppos;
+ pgoff_t idx_from = pos >> PAGE_CACHE_SHIFT;
+ pgoff_t idx_to = (pos + count - 1) >> PAGE_CACHE_SHIFT;
ssize_t res = 0;
struct fuse_req *req;
struct iov_iter ii;
@@ -1309,6 +1406,14 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,
if (IS_ERR(req))
return PTR_ERR(req);
+ if (!cuse && fuse_range_is_writeback(inode, idx_from, idx_to)) {
+ if (!write)
+ mutex_lock(&inode->i_mutex);
+ fuse_sync_writes(inode);
+ if (!write)
+ mutex_unlock(&inode->i_mutex);
+ }
+
while (count) {
size_t nres;
fl_owner_t owner = current->files;
@@ -1397,7 +1502,8 @@ static ssize_t __fuse_direct_write(struct fuse_io_priv *io,
res = generic_write_checks(file, ppos, &count, 0);
if (!res)
- res = fuse_direct_io(io, iov, nr_segs, count, ppos, 1);
+ res = fuse_direct_io(io, iov, nr_segs, count, ppos,
+ FUSE_DIO_WRITE);
fuse_invalidate_attr(inode);
@@ -1885,6 +1991,77 @@ out:
return err;
}
+/*
+ * It's worthy to make sure that space is reserved on disk for the write,
+ * but how to implement it without killing performance need more thinking.
+ */
+static int fuse_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+ struct fuse_conn *fc = get_fuse_conn(file->f_dentry->d_inode);
+ struct page *page;
+ loff_t fsize;
+ int err = -ENOMEM;
+
+ WARN_ON(!fc->writeback_cache);
+
+ page = grab_cache_page_write_begin(mapping, index, flags);
+ if (!page)
+ goto error;
+
+ fuse_wait_on_page_writeback(mapping->host, page->index);
+
+ if (PageUptodate(page) || len == PAGE_CACHE_SIZE)
+ goto success;
+ /*
+ * Check if the start this page comes after the end of file, in which
+ * case the readpage can be optimized away.
+ */
+ fsize = i_size_read(mapping->host);
+ if (fsize <= (pos & PAGE_CACHE_MASK)) {
+ size_t off = pos & ~PAGE_CACHE_MASK;
+ if (off)
+ zero_user_segment(page, 0, off);
+ goto success;
+ }
+ err = fuse_do_readpage(file, page);
+ if (err)
+ goto cleanup;
+success:
+ *pagep = page;
+ return 0;
+
+cleanup:
+ unlock_page(page);
+ page_cache_release(page);
+error:
+ return err;
+}
+
+static int fuse_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ struct inode *inode = page->mapping->host;
+
+ if (!PageUptodate(page)) {
+ /* Zero any unwritten bytes at the end of the page */
+ size_t endoff = (pos + copied) & ~PAGE_CACHE_MASK;
+ if (endoff)
+ zero_user_segment(page, endoff, PAGE_CACHE_SIZE);
+ SetPageUptodate(page);
+ }
+
+ fuse_write_update_size(inode, pos + copied);
+ set_page_dirty(page);
+ unlock_page(page);
+ page_cache_release(page);
+
+ return copied;
+}
+
static int fuse_launder_page(struct page *page)
{
int err = 0;
@@ -1946,20 +2123,9 @@ 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;
@@ -2606,7 +2772,7 @@ static void fuse_register_polled_file(struct fuse_conn *fc,
{
spin_lock(&fc->lock);
if (RB_EMPTY_NODE(&ff->polled_node)) {
- struct rb_node **link, *parent;
+ struct rb_node **link, *uninitialized_var(parent);
link = fuse_find_polled_node(fc, ff->kh, &parent);
BUG_ON(*link);
@@ -2850,8 +3016,16 @@ 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);
@@ -2915,6 +3089,8 @@ static const struct address_space_operations fuse_file_aops = {
.set_page_dirty = __set_page_dirty_nobuffers,
.bmap = fuse_bmap,
.direct_IO = fuse_direct_IO,
+ .write_begin = fuse_write_begin,
+ .write_end = fuse_write_end,
};
void fuse_init_file_inode(struct inode *inode)
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 2da5db2c8bdb..a257ed8ebee6 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
@@ -863,9 +868,20 @@ int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
bool isdir);
+
+/**
+ * fuse_direct_io() flags
+ */
+
+/** If set, it is WRITE; otherwise - READ */
+#define FUSE_DIO_WRITE (1 << 0)
+
+/** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
+#define FUSE_DIO_CUSE (1 << 1)
+
ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,
unsigned long nr_segs, size_t count, loff_t *ppos,
- int write);
+ int flags);
long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
unsigned int flags);
long fuse_ioctl_common(struct file *file, unsigned int cmd,
@@ -873,7 +889,9 @@ 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 9c761b611c54..b4bff1b15028 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -170,8 +170,11 @@ 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;
+ /* 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;
@@ -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 +253,8 @@ 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;
if (S_ISREG(inode->i_mode)) {
fuse_init_common(inode);
fuse_init_file_inode(inode);
@@ -289,7 +301,9 @@ 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);
@@ -873,6 +887,8 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
}
if (arg->flags & FUSE_ASYNC_DIO)
fc->async_dio = 1;
+ if (arg->flags & FUSE_WRITEBACK_CACHE)
+ fc->writeback_cache = 1;
} else {
ra_pages = fc->max_read / PAGE_CACHE_SIZE;
fc->no_lock = 1;
@@ -900,7 +916,8 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
- FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO;
+ FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
+ FUSE_WRITEBACK_CACHE;
req->in.h.opcode = FUSE_INIT;
req->in.numargs = 1;
req->in.args[0].size = sizeof(*arg);
diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index 60bb2f9f7b74..cf4750e1bb49 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -93,6 +93,9 @@
*
* 7.22
* - add FUSE_ASYNC_DIO
+ *
+ * 7.23
+ * - add FUSE_WRITEBACK_CACHE
*/
#ifndef _LINUX_FUSE_H
@@ -128,7 +131,7 @@
#define FUSE_KERNEL_VERSION 7
/** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 22
+#define FUSE_KERNEL_MINOR_VERSION 23
/** The node ID of the root inode */
#define FUSE_ROOT_ID 1
@@ -219,6 +222,7 @@ struct fuse_file_lock {
* FUSE_DO_READDIRPLUS: do READDIRPLUS (READDIR+LOOKUP in one)
* FUSE_READDIRPLUS_AUTO: adaptive readdirplus
* FUSE_ASYNC_DIO: asynchronous direct I/O submission
+ * FUSE_WRITEBACK_CACHE: use writeback cache for buffered writes
*/
#define FUSE_ASYNC_READ (1 << 0)
#define FUSE_POSIX_LOCKS (1 << 1)
@@ -236,6 +240,7 @@ struct fuse_file_lock {
#define FUSE_DO_READDIRPLUS (1 << 13)
#define FUSE_READDIRPLUS_AUTO (1 << 14)
#define FUSE_ASYNC_DIO (1 << 15)
+#define FUSE_WRITEBACK_CACHE (1 << 16)
/**
* CUSE INIT request/reply flags