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| author | Li Zefan <lizefan@huawei.com> | 2014-02-25 19:28:44 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-25 07:37:52 -0800 |
| commit | fed95bab8d29b928fcf6225be72d37ded452e8a2 (patch) | |
| tree | 45acbc72b0e58cc47d261b6346f99a5896dea85e /fs/kernfs | |
| parent | 6d0abeca3242a88cab8232e4acd7e2bf088f3bc2 (diff) | |
| download | linux-fed95bab8d29b928fcf6225be72d37ded452e8a2.tar.gz | |
sysfs: fix namespace refcnt leak
As mount() and kill_sb() is not a one-to-one match, we shoudn't get ns refcnt unconditionally in sysfs_mount(), and instead we should get the refcnt only when kernfs_mount() allocated a new superblock. v2: - Changed the name of the new argument, suggested by Tejun. - Made the argument optional, suggested by Tejun. v3: - Make the new argument as second-to-last arg, suggested by Tejun. Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> --- fs/kernfs/mount.c | 8 +++++++- fs/sysfs/mount.c | 5 +++-- include/linux/kernfs.h | 9 +++++---- 3 files changed, 15 insertions(+), 7 deletions(-) Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/kernfs')
| -rw-r--r-- | fs/kernfs/mount.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index 0d6ce895a9ee..0f4152defe7b 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -94,6 +94,7 @@ const void *kernfs_super_ns(struct super_block *sb) * @fs_type: file_system_type of the fs being mounted * @flags: mount flags specified for the mount * @root: kernfs_root of the hierarchy being mounted + * @new_sb_created: tell the caller if we allocated a new superblock * @ns: optional namespace tag of the mount * * This is to be called from each kernfs user's file_system_type->mount() @@ -104,7 +105,8 @@ const void *kernfs_super_ns(struct super_block *sb) * The return value can be passed to the vfs layer verbatim. */ struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags, - struct kernfs_root *root, const void *ns) + struct kernfs_root *root, bool *new_sb_created, + const void *ns) { struct super_block *sb; struct kernfs_super_info *info; @@ -122,6 +124,10 @@ struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags, kfree(info); if (IS_ERR(sb)) return ERR_CAST(sb); + + if (new_sb_created) + *new_sb_created = !sb->s_root; + if (!sb->s_root) { error = kernfs_fill_super(sb); if (error) { |