The patch titled
fix sysfs reclaim crash
has been removed from the -mm tree. Its filename was
fix-sysfs-reclaim-crash.patch
This patch was dropped because it had testing failures
------------------------------------------------------
Subject: fix sysfs reclaim crash
From: Maneesh Soni <maneesh@xxxxxxxxxx>
Maybe.
happens without i_mutex. It also nullifies s_dentry just to indicate that
the associated dentry is evicted. sysfs_readdir() access the s_dentry,
and gets the inode number from the associated dentry, if there is one, else
it invokes iunique(). This can create a race situation, and crash while
accessing the dentry/inode in sysfs_readdir().
o The following patch always use i_unique() to get the inode number. This
is ok as sysfs doesnot have permanent inode numbering. It could be slower
but avoids the above mentioned race.
o This also avoids the now unnecessary s_dentry in sysfs_d_iput().
Signed-off-by: Maneesh Soni <maneesh@xxxxxxxxxx>
Cc: Ethan Solomita <solo@xxxxxxxxxx>
Cc: Dipankar Sarma <dipankar@xxxxxxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Cc: Martin Bligh <mbligh@xxxxxxxxxx>
Cc: Rohit Seth <rohitseth@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/sysfs/dir.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff -puN fs/sysfs/dir.c~fix-sysfs-reclaim-crash fs/sysfs/dir.c
--- a/fs/sysfs/dir.c~fix-sysfs-reclaim-crash
+++ a/fs/sysfs/dir.c
@@ -20,7 +20,6 @@ static void sysfs_d_iput(struct dentry *
if (sd) {
BUG_ON(sd->s_dentry != dentry);
- sd->s_dentry = NULL;
sysfs_put(sd);
}
iput(inode);
@@ -538,10 +537,7 @@ static int sysfs_readdir(struct file * f
name = sysfs_get_name(next);
len = strlen(name);
- if (next->s_dentry)
- ino = next->s_dentry->d_inode->i_ino;
- else
- ino = iunique(sysfs_sb, 2);
+ ino = iunique(sysfs_sb, 2);
if (filldir(dirent, name, len, filp->f_pos, ino,
dt_type(next)) < 0)
_
Patches currently in -mm which might be from maneesh@xxxxxxxxxx are
fix-quadratic-behavior-of-shrink_dcache_parent.patch
fix-sysfs-reclaim-crash.patch
-
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