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* [merged] ocfs2-acl-use-ip_xattr_sem-to-protect-getting-extended-attribute.patch removed from -mm tree
@ 2018-02-01 19:29 akpm
  0 siblings, 0 replies; only message in thread
From: akpm @ 2018-02-01 19:29 UTC (permalink / raw)
  To: alex.chen, ge.changwei, jiangqi903, jlbec, junxiao.bi, mfasheh,
	mm-commits, piaojun


The patch titled
     Subject: ocfs2/acl: use 'ip_xattr_sem' to protect getting extended attribute
has been removed from the -mm tree.  Its filename was
     ocfs2-acl-use-ip_xattr_sem-to-protect-getting-extended-attribute.patch

This patch was dropped because it was merged into mainline or a subsystem tree

------------------------------------------------------
From: piaojun <piaojun@huawei.com>
Subject: 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>
---

 fs/ocfs2/acl.c   |    6 ++++++
 fs/ocfs2/xattr.c |    2 ++
 2 files changed, 8 insertions(+)

diff -puN fs/ocfs2/acl.c~ocfs2-acl-use-ip_xattr_sem-to-protect-getting-extended-attribute fs/ocfs2/acl.c
--- a/fs/ocfs2/acl.c~ocfs2-acl-use-ip_xattr_sem-to-protect-getting-extended-attribute
+++ a/fs/ocfs2/acl.c
@@ -311,7 +311,9 @@ struct posix_acl *ocfs2_iop_get_acl(stru
 	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,
 	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);
 		}
diff -puN fs/ocfs2/xattr.c~ocfs2-acl-use-ip_xattr_sem-to-protect-getting-extended-attribute fs/ocfs2/xattr.c
--- a/fs/ocfs2/xattr.c~ocfs2-acl-use-ip_xattr_sem-to-protect-getting-extended-attribute
+++ a/fs/ocfs2/xattr.c
@@ -638,9 +638,11 @@ int ocfs2_calc_xattr_init(struct inode *
 						     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))
_

Patches currently in -mm which might be from piaojun@huawei.com are



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2018-02-01 19:29 [merged] ocfs2-acl-use-ip_xattr_sem-to-protect-getting-extended-attribute.patch removed from -mm tree akpm

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