Liu Bo
2012-Jun-29 09:58 UTC
[PATCH 1/4 v2] Btrfs: check write access to mount earlier while creating snapshots
Move check of write access to mount into upper functions so that we can
use mnt_want_write_file instead, which is faster than mnt_want_write.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
---
fs/btrfs/ioctl.c | 22 +++++++++++-----------
1 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 0e92e57..b5e946e 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -652,13 +652,9 @@ static noinline int btrfs_mksubvol(struct path *parent,
if (dentry->d_inode)
goto out_dput;
- error = mnt_want_write(parent->mnt);
- if (error)
- goto out_dput;
-
error = btrfs_may_create(dir, dentry);
if (error)
- goto out_drop_write;
+ goto out_dput;
down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
@@ -676,8 +672,6 @@ static noinline int btrfs_mksubvol(struct path *parent,
fsnotify_mkdir(dir, dentry);
out_up_read:
up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
-out_drop_write:
- mnt_drop_write(parent->mnt);
out_dput:
dput(dentry);
out_unlock:
@@ -1393,16 +1387,20 @@ static noinline int
btrfs_ioctl_snap_create_transid(struct file *file,
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
+ ret = mnt_want_write_file(file);
+ if (ret)
+ goto out;
+
namelen = strlen(name);
if (strchr(name, ''/'')) {
ret = -EINVAL;
- goto out;
+ goto out_drop_write;
}
if (name[0] == ''.'' &&
(namelen == 1 || (name[1] == ''.'' && namelen ==
2))) {
ret = -EEXIST;
- goto out;
+ goto out_drop_write;
}
if (subvol) {
@@ -1413,7 +1411,7 @@ static noinline int btrfs_ioctl_snap_create_transid(struct
file *file,
src_file = fget(fd);
if (!src_file) {
ret = -EINVAL;
- goto out;
+ goto out_drop_write;
}
src_inode = src_file->f_path.dentry->d_inode;
@@ -1422,13 +1420,15 @@ static noinline int
btrfs_ioctl_snap_create_transid(struct file *file,
"another FS\n");
ret = -EINVAL;
fput(src_file);
- goto out;
+ goto out_drop_write;
}
ret = btrfs_mksubvol(&file->f_path, name, namelen,
BTRFS_I(src_inode)->root,
transid, readonly);
fput(src_file);
}
+out_drop_write:
+ mnt_drop_write_file(file);
out:
return ret;
}
--
1.6.5.2
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Liu Bo
2012-Jun-29 09:58 UTC
[PATCH 2/4 v2] Btrfs: remove redundant r/o check for superblock
mnt_want_write() and mnt_want_write_file() will check sb->s_flags with
MS_RDONLY, and we don''t need to do it ourselves.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
---
fs/btrfs/ioctl.c | 7 -------
1 files changed, 0 insertions(+), 7 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index b5e946e..069cd85 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1379,14 +1379,10 @@ static noinline int
btrfs_ioctl_snap_create_transid(struct file *file,
u64 *transid,
bool readonly)
{
- struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
struct file *src_file;
int namelen;
int ret = 0;
- if (root->fs_info->sb->s_flags & MS_RDONLY)
- return -EROFS;
-
ret = mnt_want_write_file(file);
if (ret)
goto out;
@@ -3265,9 +3261,6 @@ static long btrfs_ioctl_balance(struct file *file, void
__user *arg)
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- if (fs_info->sb->s_flags & MS_RDONLY)
- return -EROFS;
-
ret = mnt_want_write(file->f_path.mnt);
if (ret)
return ret;
--
1.6.5.2
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Liu Bo
2012-Jun-29 09:58 UTC
[PATCH 3/4 v2] Btrfs: use mnt_want_write_file instead of mnt_want_write
mnt_want_write_file is faster when file has been opened for write. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> --- fs/btrfs/ioctl.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 069cd85..df4c04d 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3261,7 +3261,7 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg) if (!capable(CAP_SYS_ADMIN)) return -EPERM; - ret = mnt_want_write(file->f_path.mnt); + ret = mnt_want_write_file(file); if (ret) return ret; @@ -3331,7 +3331,7 @@ out_bargs: out: mutex_unlock(&fs_info->balance_mutex); mutex_unlock(&fs_info->volume_mutex); - mnt_drop_write(file->f_path.mnt); + mnt_drop_write_file(file); return ret; } -- 1.6.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Liu Bo
2012-Jun-29 09:58 UTC
[PATCH 4/4 v2] Btrfs: do not set subvolume flags in readonly mode
$ mkfs.btrfs /dev/sdb7
$ btrfstune -S1 /dev/sdb7
$ mount /dev/sdb7 /mnt/btrfs
mount: block device /dev/sdb7 is write-protected, mounting read-only
$ btrfs dev add /dev/sdb8 /mnt/btrfs/
Now we get a btrfs in which mnt flags has readonly but sb flags does
not. So for those ioctls that only check sb flags with MS_RDONLY, it
is going to be a problem.
Setting subvolume flags is such an ioctl, we should use mnt_want_write_file()
to check RO flags.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
---
v1->v2: apply Tsutomu Itoh''s comments.
fs/btrfs/ioctl.c | 42 ++++++++++++++++++++++++++++--------------
1 files changed, 28 insertions(+), 14 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index df4c04d..2cf6b1b 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1519,29 +1519,40 @@ static noinline int btrfs_ioctl_subvol_setflags(struct
file *file,
u64 flags;
int ret = 0;
- if (root->fs_info->sb->s_flags & MS_RDONLY)
- return -EROFS;
+ ret = mnt_want_write_file(file);
+ if (ret)
+ goto out;
- if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
- return -EINVAL;
+ if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
+ ret = -EINVAL;
+ goto out_drop_write;
+ }
- if (copy_from_user(&flags, arg, sizeof(flags)))
- return -EFAULT;
+ if (copy_from_user(&flags, arg, sizeof(flags))) {
+ ret = -EFAULT;
+ goto out_drop_write;
+ }
- if (flags & BTRFS_SUBVOL_CREATE_ASYNC)
- return -EINVAL;
+ if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
+ ret = -EINVAL;
+ goto out_drop_write;
+ }
- if (flags & ~BTRFS_SUBVOL_RDONLY)
- return -EOPNOTSUPP;
+ if (flags & ~BTRFS_SUBVOL_RDONLY) {
+ ret = -EOPNOTSUPP;
+ goto out_drop_write;
+ }
- if (!inode_owner_or_capable(inode))
- return -EACCES;
+ if (!inode_owner_or_capable(inode)) {
+ ret = -EACCES;
+ goto out_drop_write;
+ }
down_write(&root->fs_info->subvol_sem);
/* nothing to do */
if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
- goto out;
+ goto out_drop_sem;
root_flags = btrfs_root_flags(&root->root_item);
if (flags & BTRFS_SUBVOL_RDONLY)
@@ -1564,8 +1575,11 @@ static noinline int btrfs_ioctl_subvol_setflags(struct
file *file,
out_reset:
if (ret)
btrfs_set_root_flags(&root->root_item, root_flags);
-out:
+out_drop_sem:
up_write(&root->fs_info->subvol_sem);
+out_drop_write:
+ mnt_drop_write_file(file);
+out:
return ret;
}
--
1.6.5.2
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