From 4043b886b0740ded65f633fc4b7225d624c7e658 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Mon, 16 Jan 2012 15:46:21 +0000 Subject: [PATCH 1/4] GFS2: Fix race between lru_list and glock ref count This patch fixes a narrow race window between the glock ref count hitting zero and glocks being removed from the lru_list. Signed-off-by: Steven Whitehouse --- fs/gfs2/glock.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 376816fcd040..351a3e797789 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -167,14 +167,19 @@ void gfs2_glock_add_to_lru(struct gfs2_glock *gl) spin_unlock(&lru_lock); } -static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl) +static void __gfs2_glock_remove_from_lru(struct gfs2_glock *gl) { - spin_lock(&lru_lock); if (!list_empty(&gl->gl_lru)) { list_del_init(&gl->gl_lru); atomic_dec(&lru_count); clear_bit(GLF_LRU, &gl->gl_flags); } +} + +static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl) +{ + spin_lock(&lru_lock); + __gfs2_glock_remove_from_lru(gl); spin_unlock(&lru_lock); } @@ -217,11 +222,12 @@ void gfs2_glock_put(struct gfs2_glock *gl) struct gfs2_sbd *sdp = gl->gl_sbd; struct address_space *mapping = gfs2_glock2aspace(gl); - if (atomic_dec_and_test(&gl->gl_ref)) { + if (atomic_dec_and_lock(&gl->gl_ref, &lru_lock)) { + __gfs2_glock_remove_from_lru(gl); + spin_unlock(&lru_lock); spin_lock_bucket(gl->gl_hash); hlist_bl_del_rcu(&gl->gl_list); spin_unlock_bucket(gl->gl_hash); - gfs2_glock_remove_from_lru(gl); GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); GLOCK_BUG_ON(gl, mapping && mapping->nrpages); trace_gfs2_glock_put(gl); From 718b97bd6b03445be53098e3c8f896aeebc304aa Mon Sep 17 00:00:00 2001 From: Bob Peterson Date: Thu, 16 Feb 2012 11:31:04 -0500 Subject: [PATCH 2/4] GFS2: Read in rindex if necessary during unlink This patch fixes a problem whereby you were unable to delete files until other file system operations were done (such as statfs, touch, writes, etc.) that caused the rindex to be read in. Signed-off-by: Bob Peterson Signed-off-by: Steven Whitehouse --- fs/gfs2/inode.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c index a7d611b93f0f..c87faf48f0a1 100644 --- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -1035,14 +1035,19 @@ static int gfs2_unlink(struct inode *dir, struct dentry *dentry) struct buffer_head *bh; struct gfs2_holder ghs[3]; struct gfs2_rgrpd *rgd; - int error = -EROFS; + int error; + error = gfs2_rindex_update(sdp); + if (error) + return error; gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs); gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1); rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr); - if (!rgd) + if (!rgd) { + error = -EROFS; goto out_inodes; + } gfs2_holder_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, ghs + 2); From 9e73f571ea3afffca78c1f54128d57796e27532f Mon Sep 17 00:00:00 2001 From: Bob Peterson Date: Fri, 17 Feb 2012 09:15:52 -0500 Subject: [PATCH 3/4] GFS2: Ensure rindex is uptodate for fallocate This patch fixes a problem whereby gfs2_grow was failing and causing GFS2 to assert. The problem was that when GFS2's fallocate operation tried to acquire an "allocation" it made sure the rindex was up to date, and if not, it called gfs2_rindex_update. However, if the file being fallocated was the rindex itself, it was already locked at that point. By calling gfs2_rindex_update at an earlier point in time, we bring rindex up to date and thereby avoid trying to lock it when the "allocation" is acquired. Signed-off-by: Bob Peterson Signed-off-by: Steven Whitehouse --- fs/gfs2/file.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index c5fb3597f696..7f906c8b02ac 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -772,6 +772,11 @@ static long gfs2_fallocate(struct file *file, int mode, loff_t offset, if (bytes == 0) bytes = sdp->sd_sb.sb_bsize; + error = gfs2_rindex_update(sdp); + if (error) { + fs_warn(sdp, "rindex update returns %d\n", error); + return error; + } gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh); error = gfs2_glock_nq(&ip->i_gh); if (unlikely(error)) From a365fbf354907430e6852f0c373b4b3eeff81ba3 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Fri, 24 Feb 2012 15:09:14 +0000 Subject: [PATCH 4/4] GFS2: Read resource groups on mount This makes mount take slightly longer, but at the same time, the first write to the filesystem will be faster too. It also means that if there is a problem in the resource index, then we can refuse to mount rather than having to try and report that when the first write occurs. In addition, to avoid recursive locking, we hvae to take account of instances when the rindex glock may already be held when we are trying to update the rbtree of resource groups. Signed-off-by: Steven Whitehouse --- fs/gfs2/file.c | 5 ----- fs/gfs2/inode.c | 14 +++----------- fs/gfs2/ops_fstype.c | 5 +++++ fs/gfs2/rgrp.c | 13 +++++++++---- 4 files changed, 17 insertions(+), 20 deletions(-) diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index 7f906c8b02ac..c5fb3597f696 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -772,11 +772,6 @@ static long gfs2_fallocate(struct file *file, int mode, loff_t offset, if (bytes == 0) bytes = sdp->sd_sb.sb_bsize; - error = gfs2_rindex_update(sdp); - if (error) { - fs_warn(sdp, "rindex update returns %d\n", error); - return error; - } gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh); error = gfs2_glock_nq(&ip->i_gh); if (unlikely(error)) diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c index c87faf48f0a1..56987460cdae 100644 --- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -391,10 +391,6 @@ static int alloc_dinode(struct gfs2_inode *dip, u64 *no_addr, u64 *generation) int error; int dblocks = 1; - error = gfs2_rindex_update(sdp); - if (error) - fs_warn(sdp, "rindex update returns %d\n", error); - error = gfs2_inplace_reserve(dip, RES_DINODE); if (error) goto out; @@ -1035,19 +1031,15 @@ static int gfs2_unlink(struct inode *dir, struct dentry *dentry) struct buffer_head *bh; struct gfs2_holder ghs[3]; struct gfs2_rgrpd *rgd; - int error; + int error = -EROFS; - error = gfs2_rindex_update(sdp); - if (error) - return error; gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs); gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1); rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr); - if (!rgd) { - error = -EROFS; + if (!rgd) goto out_inodes; - } + gfs2_holder_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, ghs + 2); diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index 6aacf3f230a2..24f609c9ef91 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -800,6 +800,11 @@ static int init_inodes(struct gfs2_sbd *sdp, int undo) fs_err(sdp, "can't get quota file inode: %d\n", error); goto fail_rindex; } + + error = gfs2_rindex_update(sdp); + if (error) + goto fail_qinode; + return 0; fail_qinode: diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 981bfa32121a..49ada95209d0 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -683,16 +683,21 @@ int gfs2_rindex_update(struct gfs2_sbd *sdp) struct gfs2_glock *gl = ip->i_gl; struct gfs2_holder ri_gh; int error = 0; + int unlock_required = 0; /* Read new copy from disk if we don't have the latest */ if (!sdp->sd_rindex_uptodate) { mutex_lock(&sdp->sd_rindex_mutex); - error = gfs2_glock_nq_init(gl, LM_ST_SHARED, 0, &ri_gh); - if (error) - return error; + if (!gfs2_glock_is_locked_by_me(gl)) { + error = gfs2_glock_nq_init(gl, LM_ST_SHARED, 0, &ri_gh); + if (error) + return error; + unlock_required = 1; + } if (!sdp->sd_rindex_uptodate) error = gfs2_ri_update(ip); - gfs2_glock_dq_uninit(&ri_gh); + if (unlock_required) + gfs2_glock_dq_uninit(&ri_gh); mutex_unlock(&sdp->sd_rindex_mutex); }