diff options
| -rw-r--r-- | fs/ubifs/recovery.c | 77 |
1 files changed, 50 insertions, 27 deletions
diff --git a/fs/ubifs/recovery.c b/fs/ubifs/recovery.c index 3d2598deaa58..11776ae8caf6 100644 --- a/fs/ubifs/recovery.c +++ b/fs/ubifs/recovery.c @@ -1070,6 +1070,53 @@ int ubifs_clean_lebs(const struct ubifs_info *c, void *sbuf) } /** + * grab_empty_leb - grab an empty LEB to use as GC LEB and run commit. + * @c: UBIFS file-system description object + * + * This is a helper function for 'ubifs_rcvry_gc_commit()' which grabs an empty + * LEB to be used as GC LEB (@c->gc_lnum), and then runs the commit. Returns + * zero in case of success and a negative error code in case of failure. + */ +static int grab_empty_leb(struct ubifs_info *c) +{ + int lnum, err; + + /* + * Note, it is very important to first search for an empty LEB and then + * run the commit, not vice-versa. The reason is that there might be + * only one empty LEB at the moment, the one which has been the + * @c->gc_lnum just before the power cut happened. During the regular + * UBIFS operation (not now) @c->gc_lnum is marked as "taken", so no + * one but GC can grab it. But at this moment this single empty LEB is + * not marked as taken, so if we run commit - what happens? Right, the + * commit will grab it and write the index there. Remember that the + * index always expands as long as there is free space, and it only + * starts consolidating when we run out of space. + * + * IOW, if we run commit now, we might not be able to find a free LEB + * after this. + */ + lnum = ubifs_find_free_leb_for_idx(c); + if (lnum < 0) { + dbg_err("could not find an empty LEB"); + dbg_dump_lprops(c); + dbg_dump_budg(c, &c->bi); + return lnum; + } + + /* Reset the index flag */ + err = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, + LPROPS_INDEX, 0); + if (err) + return err; + + c->gc_lnum = lnum; + dbg_rcvry("found empty LEB %d, run commit", lnum); + + return ubifs_run_commit(c); +} + +/** * ubifs_rcvry_gc_commit - recover the GC LEB number and run the commit. * @c: UBIFS file-system description object * @@ -1096,7 +1143,7 @@ int ubifs_rcvry_gc_commit(struct ubifs_info *c) c->gc_lnum = -1; if (wbuf->lnum == -1) { dbg_rcvry("no GC head LEB"); - goto find_free; + return grab_empty_leb(c); } /* * See whether the used space in the dirtiest LEB fits in the GC head @@ -1104,7 +1151,7 @@ int ubifs_rcvry_gc_commit(struct ubifs_info *c) */ if (wbuf->offs == c->leb_size) { dbg_rcvry("no room in GC head LEB"); - goto find_free; + return grab_empty_leb(c); } err = ubifs_find_dirty_leb(c, &lp, wbuf->offs, 2); if (err) { @@ -1121,7 +1168,7 @@ int ubifs_rcvry_gc_commit(struct ubifs_info *c) */ if (err == -ENOSPC) { dbg_rcvry("could not find a dirty LEB"); - goto find_free; + return grab_empty_leb(c); } return err; } @@ -1167,30 +1214,6 @@ int ubifs_rcvry_gc_commit(struct ubifs_info *c) return err; dbg_rcvry("allocated LEB %d for GC", lnum); return 0; - -find_free: - /* - * There is no GC head LEB or the free space in the GC head LEB is too - * small, or there are not dirty LEBs. Allocate gc_lnum by calling - * 'ubifs_find_free_leb_for_idx()' so GC is not run. - */ - lnum = ubifs_find_free_leb_for_idx(c); - if (lnum < 0) { - dbg_err("could not find an empty LEB"); - dbg_dump_lprops(c); - dbg_dump_budg(c, &c->bi); - return lnum; - } - /* And reset the index flag */ - err = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, - LPROPS_INDEX, 0); - if (err) - return err; - c->gc_lnum = lnum; - dbg_rcvry("allocated LEB %d for GC", lnum); - /* Run the commit */ - dbg_rcvry("committing"); - return ubifs_run_commit(c); } /** |