This is a note to let you know that I've just added the patch titled
xfs: bulkstat chunk-formatter has issues
to the 3.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xfs-bulkstat-chunk-formatter-has-issues.patch
and it can be found in the queue-3.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2b831ac6bc87d3cbcbb1a8816827b6923403e461 Mon Sep 17 00:00:00 2001
From: Dave Chinner <dchinner@xxxxxxxxxx>
Date: Fri, 7 Nov 2014 08:30:58 +1100
Subject: xfs: bulkstat chunk-formatter has issues
From: Dave Chinner <dchinner@xxxxxxxxxx>
commit 2b831ac6bc87d3cbcbb1a8816827b6923403e461 upstream.
The loop construct has issues:
- clustidx is completely unused, so remove it.
- the loop tries to be smart by terminating when the
"freecount" tells it that all inodes are free. Just drop
it as in most cases we have to scan all inodes in the
chunk anyway.
- move the "user buffer left" condition check to the only
point where we consume space int eh user buffer.
- move the initialisation of agino out of the loop, leaving
just a simple loop control logic using the clusteridx.
Also, double handling of the user buffer variables leads to problems
tracking the current state - use the cursor variables directly
rather than keeping local copies and then having to update the
cursor before returning.
Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
Signed-off-by: Dave Chinner <david@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/xfs/xfs_itable.c | 58 +++++++++++++++++++++-------------------------------
1 file changed, 24 insertions(+), 34 deletions(-)
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -283,59 +283,49 @@ xfs_bulkstat_ag_ichunk(
xfs_ino_t *lastino)
{
char __user **ubufp = acp->ac_ubuffer;
- int ubleft = acp->ac_ubleft;
- int ubelem = acp->ac_ubelem;
- int chunkidx, clustidx;
+ int chunkidx;
int error = 0;
xfs_agino_t agino;
- for (agino = irbp->ir_startino, chunkidx = clustidx = 0;
- XFS_BULKSTAT_UBLEFT(ubleft) &&
- irbp->ir_freecount < XFS_INODES_PER_CHUNK;
- chunkidx++, clustidx++, agino++) {
- int fmterror; /* bulkstat formatter result */
+ agino = irbp->ir_startino;
+ for (chunkidx = 0; chunkidx < XFS_INODES_PER_CHUNK;
+ chunkidx++, agino++) {
+ int fmterror;
int ubused;
xfs_ino_t ino = XFS_AGINO_TO_INO(mp, agno, agino);
- ASSERT(chunkidx < XFS_INODES_PER_CHUNK);
-
/* Skip if this inode is free */
if (XFS_INOBT_MASK(chunkidx) & irbp->ir_free) {
*lastino = ino;
continue;
}
- /*
- * Count used inodes as free so we can tell when the
- * chunk is used up.
- */
- irbp->ir_freecount++;
-
/* Get the inode and fill in a single buffer */
ubused = statstruct_size;
- error = formatter(mp, ino, *ubufp, ubleft, &ubused, &fmterror);
- if (fmterror == BULKSTAT_RV_NOTHING) {
- if (error && error != -ENOENT && error != -EINVAL) {
- ubleft = 0;
- break;
- }
- *lastino = ino;
- continue;
- }
- if (fmterror == BULKSTAT_RV_GIVEUP) {
- ubleft = 0;
+ error = formatter(mp, ino, *ubufp, acp->ac_ubleft,
+ &ubused, &fmterror);
+ if (fmterror == BULKSTAT_RV_GIVEUP ||
+ (error && error != -ENOENT && error != -EINVAL)) {
+ acp->ac_ubleft = 0;
ASSERT(error);
break;
}
- if (*ubufp)
- *ubufp += ubused;
- ubleft -= ubused;
- ubelem++;
+
+ /* be careful not to leak error if at end of chunk */
+ if (fmterror == BULKSTAT_RV_NOTHING || error) {
+ *lastino = ino;
+ error = 0;
+ continue;
+ }
+
+ *ubufp += ubused;
+ acp->ac_ubleft -= ubused;
+ acp->ac_ubelem++;
*lastino = ino;
- }
- acp->ac_ubleft = ubleft;
- acp->ac_ubelem = ubelem;
+ if (acp->ac_ubleft < statstruct_size)
+ break;
+ }
return error;
}
Patches currently in stable-queue which might be from dchinner@xxxxxxxxxx are
queue-3.17/xfs-bulkstat-main-loop-logic-is-a-mess.patch
queue-3.17/xfs-bulkstat-doesn-t-release-agi-buffer-on-error.patch
queue-3.17/xfs-bulkstat-chunk-formatter-has-issues.patch
queue-3.17/xfs-track-bulkstat-progress-by-agino.patch
queue-3.17/mm-remove-false-warn_on-from-pagecache_isize_extended.patch
queue-3.17/xfs-bulkstat-chunk-formatting-cursor-is-broken.patch
queue-3.17/xfs-bulkstat-error-handling-is-broken.patch
queue-3.17/xfs-bulkstat-btree-walk-doesn-t-terminate.patch
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