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| author | piaojun <piaojun@huawei.com> | 2018-01-31 16:14:59 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-01-31 17:18:35 -0800 |
| commit | 16c8d569f5704a84164f30ff01b29879f3438065 (patch) | |
| tree | c775e1a2cdba767c6d66b054eccbcc131ad428c3 /fs/ocfs2/acl.c | |
| parent | d22aa61549036c1dfb47c04c0766630b128efe40 (diff) | |
| download | blackbird-obmc-linux-16c8d569f5704a84164f30ff01b29879f3438065.tar.gz blackbird-obmc-linux-16c8d569f5704a84164f30ff01b29879f3438065.zip | |
ocfs2/acl: use 'ip_xattr_sem' to protect getting extended attribute
The race between *set_acl and *get_acl will cause getting incomplete
xattr data as below:
processA processB
ocfs2_set_acl
ocfs2_xattr_set
__ocfs2_xattr_set_handle
ocfs2_get_acl_nolock
ocfs2_xattr_get_nolock:
processB may get incomplete xattr data if processA hasn't set_acl done.
So we should use 'ip_xattr_sem' to protect getting extended attribute in
ocfs2_get_acl_nolock(), as other processes could be changing it
concurrently.
Link: http://lkml.kernel.org/r/5A5DDCFF.7030001@huawei.com
Signed-off-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Alex Chen <alex.chen@huawei.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ocfs2/acl.c')
| -rw-r--r-- | fs/ocfs2/acl.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c index 40b5cc97f7b0..917fadca8a7b 100644 --- a/fs/ocfs2/acl.c +++ b/fs/ocfs2/acl.c @@ -311,7 +311,9 @@ struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type) if (had_lock < 0) return ERR_PTR(had_lock); + down_read(&OCFS2_I(inode)->ip_xattr_sem); acl = ocfs2_get_acl_nolock(inode, type, di_bh); + up_read(&OCFS2_I(inode)->ip_xattr_sem); ocfs2_inode_unlock_tracker(inode, 0, &oh, had_lock); brelse(di_bh); @@ -330,7 +332,9 @@ int ocfs2_acl_chmod(struct inode *inode, struct buffer_head *bh) if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL)) return 0; + down_read(&OCFS2_I(inode)->ip_xattr_sem); acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, bh); + up_read(&OCFS2_I(inode)->ip_xattr_sem); if (IS_ERR(acl) || !acl) return PTR_ERR(acl); ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode); @@ -361,8 +365,10 @@ int ocfs2_init_acl(handle_t *handle, if (!S_ISLNK(inode->i_mode)) { if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) { + down_read(&OCFS2_I(dir)->ip_xattr_sem); acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT, dir_bh); + up_read(&OCFS2_I(dir)->ip_xattr_sem); if (IS_ERR(acl)) return PTR_ERR(acl); } |
