[3.19.y-ckt stable] Patch "ocfs2: fix posix_acl_create deadlock" has been added to the 3.19.y-ckt tree
Kamal Mostafa
kamal at canonical.com
Wed May 25 17:27:56 UTC 2016
This is a note to let you know that I have just added a patch titled
ocfs2: fix posix_acl_create deadlock
to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree
which can be found at:
https://git.launchpad.net/~canonical-kernel/linux/+git/linux-stable-ckt/log/?h=linux-3.19.y-queue
This patch is scheduled to be released in version 3.19.8-ckt22.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
---8<------------------------------------------------------------
>From c8df778e663a1e80fc18398fcbc045654982336a Mon Sep 17 00:00:00 2001
From: Junxiao Bi <junxiao.bi at oracle.com>
Date: Thu, 12 May 2016 15:42:18 -0700
Subject: ocfs2: fix posix_acl_create deadlock
commit c25a1e0671fbca7b2c0d0757d533bd2650d6dc0c upstream.
Commit 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure")
refactored code to use posix_acl_create. The problem with this function
is that it is not mindful of the cluster wide inode lock making it
unsuitable for use with ocfs2 inode creation with ACLs. For example,
when used in ocfs2_mknod, this function can cause deadlock as follows.
The parent dir inode lock is taken when calling posix_acl_create ->
get_acl -> ocfs2_iop_get_acl which takes the inode lock again. This can
cause deadlock if there is a blocked remote lock request waiting for the
lock to be downconverted. And same deadlock happened in ocfs2_reflink.
This fix is to revert back using ocfs2_init_acl.
Fixes: 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure")
Signed-off-by: Tariq Saeed <tariq.x.saeed at oracle.com>
Signed-off-by: Junxiao Bi <junxiao.bi at oracle.com>
Cc: Mark Fasheh <mfasheh at suse.de>
Cc: Joel Becker <jlbec at evilplan.org>
Cc: Joseph Qi <joseph.qi at huawei.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
[ kamal: backport to 3.19-stable: context ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
fs/ocfs2/acl.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++
fs/ocfs2/acl.h | 4 ++++
fs/ocfs2/namei.c | 23 ++----------------
fs/ocfs2/refcounttree.c | 17 ++-----------
fs/ocfs2/xattr.c | 14 ++++-------
fs/ocfs2/xattr.h | 4 +---
6 files changed, 77 insertions(+), 48 deletions(-)
diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
index 7e8282d..7f9e4484 100644
--- a/fs/ocfs2/acl.c
+++ b/fs/ocfs2/acl.c
@@ -310,3 +310,66 @@ struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type)
return acl;
}
+
+/*
+ * Initialize the ACLs of a new inode. If parent directory has default ACL,
+ * then clone to new inode. Called from ocfs2_mknod.
+ */
+int ocfs2_init_acl(handle_t *handle,
+ struct inode *inode,
+ struct inode *dir,
+ struct buffer_head *di_bh,
+ struct buffer_head *dir_bh,
+ struct ocfs2_alloc_context *meta_ac,
+ struct ocfs2_alloc_context *data_ac)
+{
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct posix_acl *acl = NULL;
+ int ret = 0, ret2;
+ umode_t mode;
+
+ if (!S_ISLNK(inode->i_mode)) {
+ if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
+ acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
+ dir_bh);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ }
+ if (!acl) {
+ mode = inode->i_mode & ~current_umask();
+ ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
+ if (ret) {
+ mlog_errno(ret);
+ goto cleanup;
+ }
+ }
+ }
+ if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
+ if (S_ISDIR(inode->i_mode)) {
+ ret = ocfs2_set_acl(handle, inode, di_bh,
+ ACL_TYPE_DEFAULT, acl,
+ meta_ac, data_ac);
+ if (ret)
+ goto cleanup;
+ }
+ mode = inode->i_mode;
+ ret = __posix_acl_create(&acl, GFP_NOFS, &mode);
+ if (ret < 0)
+ return ret;
+
+ ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
+ if (ret2) {
+ mlog_errno(ret2);
+ ret = ret2;
+ goto cleanup;
+ }
+ if (ret > 0) {
+ ret = ocfs2_set_acl(handle, inode,
+ di_bh, ACL_TYPE_ACCESS,
+ acl, meta_ac, data_ac);
+ }
+ }
+cleanup:
+ posix_acl_release(acl);
+ return ret;
+}
diff --git a/fs/ocfs2/acl.h b/fs/ocfs2/acl.h
index 3fce68d..1c7203d 100644
--- a/fs/ocfs2/acl.h
+++ b/fs/ocfs2/acl.h
@@ -35,5 +35,9 @@ int ocfs2_set_acl(handle_t *handle,
struct posix_acl *acl,
struct ocfs2_alloc_context *meta_ac,
struct ocfs2_alloc_context *data_ac);
+extern int ocfs2_init_acl(handle_t *, struct inode *, struct inode *,
+ struct buffer_head *, struct buffer_head *,
+ struct ocfs2_alloc_context *,
+ struct ocfs2_alloc_context *);
#endif /* OCFS2_ACL_H */
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index 9dae8f6..8f7f5de 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -253,7 +253,6 @@ static int ocfs2_mknod(struct inode *dir,
struct ocfs2_dir_lookup_result lookup = { NULL, };
sigset_t oldset;
int did_block_signals = 0;
- struct posix_acl *default_acl = NULL, *acl = NULL;
struct ocfs2_dentry_lock *dl = NULL;
trace_ocfs2_mknod(dir, dentry, dentry->d_name.len, dentry->d_name.name,
@@ -356,12 +355,6 @@ static int ocfs2_mknod(struct inode *dir,
goto leave;
}
- status = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
- if (status) {
- mlog_errno(status);
- goto leave;
- }
-
handle = ocfs2_start_trans(osb, ocfs2_mknod_credits(osb->sb,
S_ISDIR(mode),
xattr_credits));
@@ -410,16 +403,8 @@ static int ocfs2_mknod(struct inode *dir,
inc_nlink(dir);
}
- if (default_acl) {
- status = ocfs2_set_acl(handle, inode, new_fe_bh,
- ACL_TYPE_DEFAULT, default_acl,
- meta_ac, data_ac);
- }
- if (!status && acl) {
- status = ocfs2_set_acl(handle, inode, new_fe_bh,
- ACL_TYPE_ACCESS, acl,
- meta_ac, data_ac);
- }
+ status = ocfs2_init_acl(handle, inode, dir, new_fe_bh, parent_fe_bh,
+ meta_ac, data_ac);
if (status < 0) {
mlog_errno(status);
@@ -461,10 +446,6 @@ static int ocfs2_mknod(struct inode *dir,
d_instantiate(dentry, inode);
status = 0;
leave:
- if (default_acl)
- posix_acl_release(default_acl);
- if (acl)
- posix_acl_release(acl);
if (status < 0 && did_quota_inode)
dquot_free_inode(inode);
if (handle)
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index d81f6e2..18e8b4d 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -4268,20 +4268,12 @@ static int ocfs2_reflink(struct dentry *old_dentry, struct inode *dir,
struct inode *inode = old_dentry->d_inode;
struct buffer_head *old_bh = NULL;
struct inode *new_orphan_inode = NULL;
- struct posix_acl *default_acl, *acl;
- umode_t mode;
if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb)))
return -EOPNOTSUPP;
- mode = inode->i_mode;
- error = posix_acl_create(dir, &mode, &default_acl, &acl);
- if (error) {
- mlog_errno(error);
- goto out;
- }
- error = ocfs2_create_inode_in_orphan(dir, mode,
+ error = ocfs2_create_inode_in_orphan(dir, inode->i_mode,
&new_orphan_inode);
if (error) {
mlog_errno(error);
@@ -4320,16 +4312,11 @@ static int ocfs2_reflink(struct dentry *old_dentry, struct inode *dir,
/* If the security isn't preserved, we need to re-initialize them. */
if (!preserve) {
error = ocfs2_init_security_and_acl(dir, new_orphan_inode,
- &new_dentry->d_name,
- default_acl, acl);
+ &new_dentry->d_name);
if (error)
mlog_errno(error);
}
out:
- if (default_acl)
- posix_acl_release(default_acl);
- if (acl)
- posix_acl_release(acl);
if (!error) {
error = ocfs2_mv_orphaned_inode_to_new(dir, new_orphan_inode,
new_dentry);
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 662f8de..20edd59 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -7207,12 +7207,10 @@ out:
*/
int ocfs2_init_security_and_acl(struct inode *dir,
struct inode *inode,
- const struct qstr *qstr,
- struct posix_acl *default_acl,
- struct posix_acl *acl)
+ const struct qstr *qstr)
{
- struct buffer_head *dir_bh = NULL;
int ret = 0;
+ struct buffer_head *dir_bh = NULL;
ret = ocfs2_init_security_get(inode, dir, qstr, NULL);
if (ret) {
@@ -7225,11 +7223,9 @@ int ocfs2_init_security_and_acl(struct inode *dir,
mlog_errno(ret);
goto leave;
}
-
- if (!ret && default_acl)
- ret = ocfs2_iop_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
- if (!ret && acl)
- ret = ocfs2_iop_set_acl(inode, acl, ACL_TYPE_ACCESS);
+ ret = ocfs2_init_acl(NULL, inode, dir, NULL, dir_bh, NULL, NULL);
+ if (ret)
+ mlog_errno(ret);
ocfs2_inode_unlock(dir, 0);
brelse(dir_bh);
diff --git a/fs/ocfs2/xattr.h b/fs/ocfs2/xattr.h
index f10d5b9..1633cc1 100644
--- a/fs/ocfs2/xattr.h
+++ b/fs/ocfs2/xattr.h
@@ -94,7 +94,5 @@ int ocfs2_reflink_xattrs(struct inode *old_inode,
bool preserve_security);
int ocfs2_init_security_and_acl(struct inode *dir,
struct inode *inode,
- const struct qstr *qstr,
- struct posix_acl *default_acl,
- struct posix_acl *acl);
+ const struct qstr *qstr);
#endif /* OCFS2_XATTR_H */
--
2.7.4
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