| Message ID | a605146bb4b492462c44a5c8697533a40b9f57bb.1502426715.git.osandov@fb.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
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On Thu, Aug 10, 2017 at 09:45:45PM -0700, Omar Sandoval wrote: Looks ok, will test... Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> --D > From: Omar Sandoval <osandov@fb.com> > > When we try to allocate a free inode by searching the inobt, we try to > find the inode nearest the parent inode by searching chunks both left > and right of the chunk containing the parent. As an optimization, we > cache the leftmost and rightmost records that we previously searched; if > we do another allocation with the same parent inode, we'll pick up the > search where it last left off. > > There's a bug in the case where we found a free inode to the left of the > parent's chunk: we need to update the cached left and right records, but > because we already reassigned the right record to point to the left, we > end up assigning the left record to both the cached left and right > records. > > This isn't a correctness problem strictly, but it can result in the next > allocation rechecking chunks unnecessarily or allocating inodes further > away from the parent than it needs to. Fix it by swapping the record > pointer after we update the cached left and right records. > > Fixes: bd169565993b ("xfs: speed up free inode search") > Signed-off-by: Omar Sandoval <osandov@fb.com> > --- > fs/xfs/libxfs/xfs_ialloc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c > index ffd5a15d1bb6..abf5beaae907 100644 > --- a/fs/xfs/libxfs/xfs_ialloc.c > +++ b/fs/xfs/libxfs/xfs_ialloc.c > @@ -1246,13 +1246,13 @@ xfs_dialloc_ag_inobt( > > /* free inodes to the left? */ > if (useleft && trec.ir_freecount) { > - rec = trec; > xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); > cur = tcur; > > pag->pagl_leftrec = trec.ir_startino; > pag->pagl_rightrec = rec.ir_startino; > pag->pagl_pagino = pagino; > + rec = trec; > goto alloc_inode; > } > > -- > 2.14.0 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c index ffd5a15d1bb6..abf5beaae907 100644 --- a/fs/xfs/libxfs/xfs_ialloc.c +++ b/fs/xfs/libxfs/xfs_ialloc.c @@ -1246,13 +1246,13 @@ xfs_dialloc_ag_inobt( /* free inodes to the left? */ if (useleft && trec.ir_freecount) { - rec = trec; xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); cur = tcur; pag->pagl_leftrec = trec.ir_startino; pag->pagl_rightrec = rec.ir_startino; pag->pagl_pagino = pagino; + rec = trec; goto alloc_inode; }