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authorpiaojun <piaojun@huawei.com>2018-02-01 03:14:59 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-02-01 04:18:35 +0300
commit16c8d569f5704a84164f30ff01b29879f3438065 (patch)
treec775e1a2cdba767c6d66b054eccbcc131ad428c3 /fs/ocfs2/xattr.c
parentd22aa61549036c1dfb47c04c0766630b128efe40 (diff)
downloadlinux-16c8d569f5704a84164f30ff01b29879f3438065.tar.xz
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/xattr.c')
-rw-r--r--fs/ocfs2/xattr.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 268619c96b4e..c261c1dfd374 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -638,9 +638,11 @@ 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))