lkml.org 
[lkml]   [2015]   [May]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 092/110] namei: explicitly pass seq number to unlazy_walk() when dentry != NULL
Date
From: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/namei.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 756e150..97315df 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;
}

--
2.1.4


\
 
 \ /
  Last update: 2015-05-11 20:41    [W:0.540 / U:10.112 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site