From cc0581bd6132984641e47809552fc9d5dfcadbcf Mon Sep 17 00:00:00 2001 From: Bob Peterson Date: Tue, 11 May 2010 17:58:11 -0400 Subject: [PATCH] GFS2: stuck in inode wait, no glocks stuck This patch changes the lock ordering when gfs2 reclaims unlinked dinodes, thereby avoiding a livelock. Signed-off-by: Bob Peterson Signed-off-by: Steven Whitehouse --- fs/gfs2/rgrp.c | 78 +++++++++++++++++++------------------------------- 1 file changed, 30 insertions(+), 48 deletions(-) diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 37391550284f..8bce73ed4d8e 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -952,16 +952,14 @@ static int try_rgrp_fit(struct gfs2_rgrpd *rgd, struct gfs2_alloc *al) * The inode, if one has been found, in inode. */ -static int try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked, - u64 skip, struct inode **inode) +static u64 try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked, + u64 skip) { 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; @@ -981,10 +979,7 @@ static int try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked, if (no_addr == skip) continue; *last_unlinked = no_addr; - error = gfs2_unlinked_inode_lookup(rgd->rd_sbd->sd_vfs, - no_addr, inode); - if (*inode || error) - return error; + return no_addr; } rgd->rd_flags &= ~GFS2_RDF_CHECK; @@ -1069,11 +1064,12 @@ static void forward_rgrp_set(struct gfs2_sbd *sdp, struct gfs2_rgrpd *rgd) * Try to acquire rgrp in way which avoids contending with others. * * Returns: errno + * unlinked: the block address of an unlinked block to be reclaimed */ -static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) +static int get_local_rgrp(struct gfs2_inode *ip, u64 *unlinked, + u64 *last_unlinked) { - struct inode *inode = NULL; struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); struct gfs2_rgrpd *rgd, *begin = NULL; struct gfs2_alloc *al = ip->i_alloc; @@ -1082,6 +1078,7 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) int loops = 0; int error, rg_locked; + *unlinked = 0; rgd = gfs2_blk2rgrpd(sdp, ip->i_goal); while (rgd) { @@ -1103,29 +1100,19 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) 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); + *unlinked = try_rgrp_unlink(rgd, last_unlinked, + ip->i_no_addr); if (!rg_locked) gfs2_glock_dq_uninit(&al->al_rgd_gh); - 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); + if (*unlinked) + return -EAGAIN; /* fall through */ case GLR_TRYFAILED: rgd = recent_rgrp_next(rgd); break; default: - return ERR_PTR(error); + return error; } } @@ -1148,22 +1135,12 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) if (try_rgrp_fit(rgd, al)) goto out; if (!rg_locked && rgd->rd_flags & GFS2_RDF_CHECK) - error = try_rgrp_unlink(rgd, last_unlinked, - ip->i_no_addr, &inode); + *unlinked = try_rgrp_unlink(rgd, last_unlinked, + ip->i_no_addr); if (!rg_locked) gfs2_glock_dq_uninit(&al->al_rgd_gh); - 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); + if (*unlinked) + return -EAGAIN; break; case GLR_TRYFAILED: @@ -1171,7 +1148,7 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) break; default: - return ERR_PTR(error); + return error; } rgd = gfs2_rgrpd_get_next(rgd); @@ -1180,7 +1157,7 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) if (rgd == begin) { if (++loops >= 3) - return ERR_PTR(-ENOSPC); + return -ENOSPC; if (!skipped) loops++; flags = 0; @@ -1200,7 +1177,7 @@ out: forward_rgrp_set(sdp, rgd); } - return NULL; + return 0; } /** @@ -1216,7 +1193,7 @@ int gfs2_inplace_reserve_i(struct gfs2_inode *ip, char *file, unsigned int line) struct gfs2_alloc *al = ip->i_alloc; struct inode *inode; int error = 0; - u64 last_unlinked = NO_BLOCK; + u64 last_unlinked = NO_BLOCK, unlinked; if (gfs2_assert_warn(sdp, al->al_requested)) return -EINVAL; @@ -1232,14 +1209,19 @@ try_again: if (error) return error; - inode = get_local_rgrp(ip, &last_unlinked); - if (inode) { + error = get_local_rgrp(ip, &unlinked, &last_unlinked); + if (error) { if (ip != GFS2_I(sdp->sd_rindex)) gfs2_glock_dq_uninit(&al->al_ri_gh); - if (IS_ERR(inode)) - return PTR_ERR(inode); - iput(inode); + if (error != -EAGAIN) + return error; + error = gfs2_unlinked_inode_lookup(ip->i_inode.i_sb, + unlinked, &inode); + if (inode) + iput(inode); gfs2_log_flush(sdp, NULL); + if (error == GLR_TRYFAILED) + error = 0; goto try_again; } -- 2.20.1