diff options
| author | piaojun <piaojun@huawei.com> | 2018-01-31 16:14:59 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-30 07:48:55 +0200 |
| commit | b35bb8a41795caa05e09c3aacf7d78f1f20bac04 (patch) | |
| tree | fe6213fc92aec7177849323e5a74e5610fec45fa /fs | |
| parent | d55cd5742835f03e5c155d865499c64c8312c1e2 (diff) | |
ocfs2/acl: use 'ip_xattr_sem' to protect getting extended attribute
[ Upstream commit 16c8d569f5704a84164f30ff01b29879f3438065 ]
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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ocfs2/acl.c | 6 | ||||
| -rw-r--r-- | fs/ocfs2/xattr.c | 2 |
2 files changed, 8 insertions, 0 deletions
diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c index 164307b99405..1e0d8da0d3cd 100644 --- a/fs/ocfs2/acl.c +++ b/fs/ocfs2/acl.c @@ -314,7 +314,9 @@ struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type) return ERR_PTR(ret); } + 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(inode, 0); brelse(di_bh); @@ -333,7 +335,9 @@ 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); @@ -364,8 +368,10 @@ 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); } diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c index 877830b05e12..4f0788232f2f 100644 --- a/fs/ocfs2/xattr.c +++ b/fs/ocfs2/xattr.c @@ -639,9 +639,11 @@ int ocfs2_calc_xattr_init(struct inode *dir, si->value_len); if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) { + down_read(&OCFS2_I(dir)->ip_xattr_sem); acl_len = ocfs2_xattr_get_nolock(dir, dir_bh, OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT, "", NULL, 0); + up_read(&OCFS2_I(dir)->ip_xattr_sem); if (acl_len > 0) { a_size = ocfs2_xattr_entry_real_size(0, acl_len); if (S_ISDIR(mode)) |