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authorDave Chinner <dchinner@redhat.com>2014-11-07 08:30:58 +1100
committerDave Chinner <david@fromorbit.com>2014-11-07 08:30:58 +1100
commit2b831ac6bc87d3cbcbb1a8816827b6923403e461 (patch)
treee1c5fb18fa99b4a6b025d716e29793df06861119
parentbf4a5af20d25ecc8876978ad34b8db83b4235f3c (diff)
xfs: bulkstat chunk-formatter has issues
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. cc: <stable@vger.kernel.org> # 3.17 Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
-rw-r--r--fs/xfs/xfs_itable.c58
1 files changed, 24 insertions, 34 deletions
diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index 50a3e5995dd9..7ea2b113db1b 100644
--- 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;
}