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author | Darrick J. Wong <darrick.wong@oracle.com> | 2019-07-01 18:25:35 +0300 |
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committer | Darrick J. Wong <darrick.wong@oracle.com> | 2019-07-01 18:25:35 +0300 |
commit | 7b0e492e6b80d51db4156996b248522c7b50d467 (patch) | |
tree | 7b7e23b0a4bc9c2a97b1af4cb977cf0a5033ca59 /fs/inode.c | |
parent | 5aca284210ce827f780ea2f4f9c6ab8d6e2d6648 (diff) | |
download | linux-7b0e492e6b80d51db4156996b248522c7b50d467.tar.xz |
vfs: create a generic checking function for FS_IOC_FSSETXATTR
Create a generic checking function for the incoming FS_IOC_FSSETXATTR
fsxattr values so that we can standardize some of the implementation
behaviors.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/inode.c')
-rw-r--r-- | fs/inode.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/fs/inode.c b/fs/inode.c index 8072a09fd0b9..ba2bafa22885 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2194,3 +2194,26 @@ int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags, return 0; } EXPORT_SYMBOL(vfs_ioc_setflags_prepare); + +/* + * Generic function to check FS_IOC_FSSETXATTR values and reject any invalid + * configurations. + * + * Note: the caller should be holding i_mutex, or else be sure that they have + * exclusive access to the inode structure. + */ +int vfs_ioc_fssetxattr_check(struct inode *inode, const struct fsxattr *old_fa, + struct fsxattr *fa) +{ + /* + * Can't modify an immutable/append-only file unless we have + * appropriate permission. + */ + if ((old_fa->fsx_xflags ^ fa->fsx_xflags) & + (FS_XFLAG_IMMUTABLE | FS_XFLAG_APPEND) && + !capable(CAP_LINUX_IMMUTABLE)) + return -EPERM; + + return 0; +} +EXPORT_SYMBOL(vfs_ioc_fssetxattr_check); |