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authorAndreas Rohner <andreas.rohner@gmx.net>2014-04-03 14:50:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-03 16:21:25 -0700
commit2cc88f3a5f16ae9a3c8f54de1b2fd4a397b36075 (patch)
treeeccf104b99fbaca714acd78ebe90b574f408f0fe
parent00e9ffcd27cc5d0af9076383c6242c32335546f8 (diff)
downloadlinux-linaro-stable-2cc88f3a5f16ae9a3c8f54de1b2fd4a397b36075.tar.gz
nilfs2: implementation of NILFS_IOCTL_SET_SUINFO ioctl
With this ioctl the segment usage entries in the SUFILE can be updated from userspace. This is useful, because it allows the userspace GC to modify and update segment usage entries for specific segments, which enables it to avoid unnecessary write operations. If a segment needs to be cleaned, but there is no or very little reclaimable space in it, the cleaning operation basically degrades to a useless moving operation. In the end the only thing that changes is the location of the data and a timestamp in the segment usage information. With this ioctl the GC can skip the cleaning and update the segment usage entries directly instead. This is basically a shortcut to cleaning the segment. It is still necessary to read the segment summary information, but the writing of the live blocks can be skipped if it's not worth it. [konishi.ryusuke@lab.ntt.co.jp: add description of NILFS_IOCTL_SET_SUINFO ioctl] Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--Documentation/filesystems/nilfs2.txt7
-rw-r--r--fs/nilfs2/ioctl.c92
-rw-r--r--include/linux/nilfs2_fs.h2
3 files changed, 101 insertions, 0 deletions
diff --git a/Documentation/filesystems/nilfs2.txt b/Documentation/filesystems/nilfs2.txt
index 06887d46ccf2..8b887ae4e39e 100644
--- a/Documentation/filesystems/nilfs2.txt
+++ b/Documentation/filesystems/nilfs2.txt
@@ -111,6 +111,13 @@ Table of NILFS2 specific ioctls
nilfs_resize utilities and by nilfs_cleanerd
daemon.
+ NILFS_IOCTL_SET_SUINFO Modify segment usage info of requested
+ segments. This ioctl is used by
+ nilfs_cleanerd daemon to skip unnecessary
+ cleaning operation of segments and reduce
+ performance penalty or wear of flash device
+ due to redundant move of in-use blocks.
+
NILFS_IOCTL_GET_SUSTAT Return segment usage statistics. This ioctl
is used in lssu, nilfs_resize utilities and
by nilfs_cleanerd daemon.
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index 2b34021948e4..c19a23158487 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -1163,6 +1163,95 @@ static int nilfs_ioctl_get_info(struct inode *inode, struct file *filp,
return ret;
}
+/**
+ * nilfs_ioctl_set_suinfo - set segment usage info
+ * @inode: inode object
+ * @filp: file object
+ * @cmd: ioctl's request code
+ * @argp: pointer on argument from userspace
+ *
+ * Description: Expects an array of nilfs_suinfo_update structures
+ * encapsulated in nilfs_argv and updates the segment usage info
+ * according to the flags in nilfs_suinfo_update.
+ *
+ * Return Value: On success, 0 is returned. On error, one of the
+ * following negative error codes is returned.
+ *
+ * %-EPERM - Not enough permissions
+ *
+ * %-EFAULT - Error copying input data
+ *
+ * %-EIO - I/O error.
+ *
+ * %-ENOMEM - Insufficient amount of memory available.
+ *
+ * %-EINVAL - Invalid values in input (segment number, flags or nblocks)
+ */
+static int nilfs_ioctl_set_suinfo(struct inode *inode, struct file *filp,
+ unsigned int cmd, void __user *argp)
+{
+ struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
+ struct nilfs_transaction_info ti;
+ struct nilfs_argv argv;
+ size_t len;
+ void __user *base;
+ void *kbuf;
+ int ret;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
+ ret = -EFAULT;
+ if (copy_from_user(&argv, argp, sizeof(argv)))
+ goto out;
+
+ ret = -EINVAL;
+ if (argv.v_size < sizeof(struct nilfs_suinfo_update))
+ goto out;
+
+ if (argv.v_nmembs > nilfs->ns_nsegments)
+ goto out;
+
+ if (argv.v_nmembs >= UINT_MAX / argv.v_size)
+ goto out;
+
+ len = argv.v_size * argv.v_nmembs;
+ if (!len) {
+ ret = 0;
+ goto out;
+ }
+
+ base = (void __user *)(unsigned long)argv.v_base;
+ kbuf = vmalloc(len);
+ if (!kbuf) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (copy_from_user(kbuf, base, len)) {
+ ret = -EFAULT;
+ goto out_free;
+ }
+
+ nilfs_transaction_begin(inode->i_sb, &ti, 0);
+ ret = nilfs_sufile_set_suinfo(nilfs->ns_sufile, kbuf, argv.v_size,
+ argv.v_nmembs);
+ if (unlikely(ret < 0))
+ nilfs_transaction_abort(inode->i_sb);
+ else
+ nilfs_transaction_commit(inode->i_sb); /* never fails */
+
+out_free:
+ vfree(kbuf);
+out:
+ mnt_drop_write_file(filp);
+ return ret;
+}
+
long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
@@ -1189,6 +1278,8 @@ long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return nilfs_ioctl_get_info(inode, filp, cmd, argp,
sizeof(struct nilfs_suinfo),
nilfs_ioctl_do_get_suinfo);
+ case NILFS_IOCTL_SET_SUINFO:
+ return nilfs_ioctl_set_suinfo(inode, filp, cmd, argp);
case NILFS_IOCTL_GET_SUSTAT:
return nilfs_ioctl_get_sustat(inode, filp, cmd, argp);
case NILFS_IOCTL_GET_VINFO:
@@ -1228,6 +1319,7 @@ long nilfs_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
case NILFS_IOCTL_GET_CPINFO:
case NILFS_IOCTL_GET_CPSTAT:
case NILFS_IOCTL_GET_SUINFO:
+ case NILFS_IOCTL_SET_SUINFO:
case NILFS_IOCTL_GET_SUSTAT:
case NILFS_IOCTL_GET_VINFO:
case NILFS_IOCTL_GET_BDESCS:
diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h
index 252657874a19..1fb465f9baf2 100644
--- a/include/linux/nilfs2_fs.h
+++ b/include/linux/nilfs2_fs.h
@@ -905,5 +905,7 @@ struct nilfs_bdesc {
_IOW(NILFS_IOCTL_IDENT, 0x8B, __u64)
#define NILFS_IOCTL_SET_ALLOC_RANGE \
_IOW(NILFS_IOCTL_IDENT, 0x8C, __u64[2])
+#define NILFS_IOCTL_SET_SUINFO \
+ _IOW(NILFS_IOCTL_IDENT, 0x8D, struct nilfs_argv)
#endif /* _LINUX_NILFS_FS_H */