diff options
| author | Bob Peterson <rpeterso@redhat.com> | 2010-04-14 11:58:16 -0400 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2010-04-14 16:48:05 +0100 |
| commit | 1a0eae8848cde6e0734360f6456496c995ee1e23 (patch) | |
| tree | 536f944468ef5bc6f47ec09325422adbc5a3907a /fs/gfs2/rgrp.c | |
| parent | 602c89d2e3e8652f94a697c9a919be739b9bcdd5 (diff) | |
GFS2: glock livelock
This patch fixes a couple gfs2 problems with the reclaiming of
unlinked dinodes. First, there were a couple of livelocks where
everything would come to a halt waiting for a glock that was
seemingly held by a process that no longer existed. In fact, the
process did exist, it just had the wrong pid number in the holder
information. Second, there was a lock ordering problem between
inode locking and glock locking. Third, glock/inode contention
could sometimes cause inodes to be improperly marked invalid by
iget_failed.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Diffstat (limited to 'fs/gfs2/rgrp.c')
| -rw-r--r-- | fs/gfs2/rgrp.c | 58 |
1 files changed, 43 insertions, 15 deletions
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 503b842f3ba2..37391550284f 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -948,18 +948,20 @@ static int try_rgrp_fit(struct gfs2_rgrpd *rgd, struct gfs2_alloc *al) * try_rgrp_unlink - Look for any unlinked, allocated, but unused inodes * @rgd: The rgrp * - * Returns: The inode, if one has been found + * Returns: 0 if no error + * The inode, if one has been found, in inode. */ -static struct inode *try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked, - u64 skip) +static int try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked, + u64 skip, struct inode **inode) { - struct inode *inode; u32 goal = 0, block; u64 no_addr; struct gfs2_sbd *sdp = rgd->rd_sbd; unsigned int n; + int error = 0; + *inode = NULL; for(;;) { if (goal >= rgd->rd_data) break; @@ -979,14 +981,14 @@ static struct inode *try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked, if (no_addr == skip) continue; *last_unlinked = no_addr; - inode = gfs2_inode_lookup(rgd->rd_sbd->sd_vfs, DT_UNKNOWN, - no_addr, -1, 1); - if (!IS_ERR(inode)) - return inode; + error = gfs2_unlinked_inode_lookup(rgd->rd_sbd->sd_vfs, + no_addr, inode); + if (*inode || error) + return error; } rgd->rd_flags &= ~GFS2_RDF_CHECK; - return NULL; + return 0; } /** @@ -1096,12 +1098,27 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) case 0: if (try_rgrp_fit(rgd, al)) goto out; - if (rgd->rd_flags & GFS2_RDF_CHECK) - inode = try_rgrp_unlink(rgd, last_unlinked, ip->i_no_addr); + /* If the rg came in already locked, there's no + way we can recover from a failed try_rgrp_unlink + because that would require an iput which can only + happen after the rgrp is unlocked. */ + if (!rg_locked && rgd->rd_flags & GFS2_RDF_CHECK) + error = try_rgrp_unlink(rgd, last_unlinked, + ip->i_no_addr, &inode); if (!rg_locked) gfs2_glock_dq_uninit(&al->al_rgd_gh); - if (inode) + if (inode) { + if (error) { + if (inode->i_state & I_NEW) + iget_failed(inode); + else + iput(inode); + return ERR_PTR(error); + } return inode; + } + if (error) + return ERR_PTR(error); /* fall through */ case GLR_TRYFAILED: rgd = recent_rgrp_next(rgd); @@ -1130,12 +1147,23 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) case 0: if (try_rgrp_fit(rgd, al)) goto out; - if (rgd->rd_flags & GFS2_RDF_CHECK) - inode = try_rgrp_unlink(rgd, last_unlinked, ip->i_no_addr); + if (!rg_locked && rgd->rd_flags & GFS2_RDF_CHECK) + error = try_rgrp_unlink(rgd, last_unlinked, + ip->i_no_addr, &inode); if (!rg_locked) gfs2_glock_dq_uninit(&al->al_rgd_gh); - if (inode) + if (inode) { + if (error) { + if (inode->i_state & I_NEW) + iget_failed(inode); + else + iput(inode); + return ERR_PTR(error); + } return inode; + } + if (error) + return ERR_PTR(error); break; case GLR_TRYFAILED: |