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authorAl Viro <viro@zeniv.linux.org.uk>2015-05-05 09:26:05 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2015-05-11 08:13:09 -0400
commit6e9918b7b3924f7a4cc3faa73c6e15d709ac239f (patch)
tree59b077f64568e4d43c837be2775bc7480ae9ec82 /fs
parent3595e2346cd91c223efddc79353fe7ced81f21bf (diff)
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namei: explicitly pass seq number to unlazy_walk() when dentry != NULL
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
-rw-r--r--fs/namei.c15
1 files changed, 8 insertions, 7 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 756e150c28fc..97315dfcf464 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -567,13 +567,14 @@ static inline int nd_alloc_stack(struct nameidata *nd)
* unlazy_walk - try to switch to ref-walk mode.
* @nd: nameidata pathwalk data
* @dentry: child of nd->path.dentry or NULL
+ * @seq: seq number to check dentry against
* Returns: 0 on success, -ECHILD on failure
*
* unlazy_walk attempts to legitimize the current nd->path, nd->root and dentry
* for ref-walk mode. @dentry must be a path found by a do_lookup call on
* @nd or NULL. Must be called from rcu-walk context.
*/
-static int unlazy_walk(struct nameidata *nd, struct dentry *dentry)
+static int unlazy_walk(struct nameidata *nd, struct dentry *dentry, unsigned seq)
{
struct fs_struct *fs = current->fs;
struct dentry *parent = nd->path.dentry;
@@ -615,7 +616,7 @@ static int unlazy_walk(struct nameidata *nd, struct dentry *dentry)
} else {
if (!lockref_get_not_dead(&dentry->d_lockref))
goto out;
- if (read_seqcount_retry(&dentry->d_seq, nd->seq))
+ if (read_seqcount_retry(&dentry->d_seq, seq))
goto drop_dentry;
}
@@ -671,7 +672,7 @@ static int complete_walk(struct nameidata *nd)
if (nd->flags & LOOKUP_RCU) {
if (!(nd->flags & LOOKUP_ROOT))
nd->root.mnt = NULL;
- if (unlikely(unlazy_walk(nd, NULL)))
+ if (unlikely(unlazy_walk(nd, NULL, 0)))
return -ECHILD;
}
@@ -1451,7 +1452,7 @@ static int lookup_fast(struct nameidata *nd,
if (likely(__follow_mount_rcu(nd, path, inode)))
return 0;
unlazy:
- if (unlazy_walk(nd, dentry))
+ if (unlazy_walk(nd, dentry, nd->seq))
return -ECHILD;
} else {
dentry = __d_lookup(parent, &nd->last);
@@ -1511,7 +1512,7 @@ static inline int may_lookup(struct nameidata *nd)
int err = inode_permission(nd->inode, MAY_EXEC|MAY_NOT_BLOCK);
if (err != -ECHILD)
return err;
- if (unlazy_walk(nd, NULL))
+ if (unlazy_walk(nd, NULL, 0))
return -ECHILD;
}
return inode_permission(nd->inode, MAY_EXEC);
@@ -1552,7 +1553,7 @@ static int pick_link(struct nameidata *nd, struct path *link)
}
if (nd->flags & LOOKUP_RCU) {
if (unlikely(nd->path.mnt != link->mnt ||
- unlazy_walk(nd, link->dentry))) {
+ unlazy_walk(nd, link->dentry, nd->seq))) {
return -ECHILD;
}
}
@@ -2297,7 +2298,7 @@ mountpoint_last(struct nameidata *nd, struct path *path)
/* If we're in rcuwalk, drop out of it to handle last component */
if (nd->flags & LOOKUP_RCU) {
- if (unlazy_walk(nd, NULL))
+ if (unlazy_walk(nd, NULL, 0))
return -ECHILD;
}