gfs2: Revert "Fix loop in gfs2_rbm_find"

Andreas Gruenbacher · torvalds · commit e74c98ca2d6a · 2019-01-31T11:45:11.000-08:00
This reverts commit 2d29f6b. It turns out that the fix can lead to a ~20 percent performance regression in initial writes to the page cache according to iozone. Let's revert this for now to have more time for a proper fix. Cc: stable@vger.kernel.org # v3.13+ Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
@@ -1780,9 +1780,9 @@ static int gfs2_rbm_find(struct gfs2_rbm *rbm, u8 state, u32 *minext,
 			goto next_iter;
 		}
 		if (ret == -E2BIG) {
-			n += rbm->bii - initial_bii;
 			rbm->bii = 0;
 			rbm->offset = 0;
+			n += (rbm->bii - initial_bii);
 			goto res_covered_end_of_rgrp;
 		}
 		return ret;

Original file line number	Diff line number	Diff line change
`@@ -1780,9 +1780,9 @@ static int gfs2_rbm_find(struct gfs2_rbm rbm, u8 state, u32 minext,`
`1780`	`1780`	`goto next_iter;`
`1781`	`1781`	`}`
`1782`	`1782`	`if (ret == -E2BIG) {`
`1783`		`- n += rbm->bii - initial_bii;`
`1784`	`1783`	`rbm->bii = 0;`
`1785`	`1784`	`rbm->offset = 0;`
	`1785`	`+ n += (rbm->bii - initial_bii);`
`1786`	`1786`	`goto res_covered_end_of_rgrp;`
`1787`	`1787`	`}`
`1788`	`1788`	`return ret;`