GFS2: Pre-pull patch posting (fixes)

GFS2: Pre-pull patch posting (fixes)

[Steven Whitehouse]

Hi,

Here are four patches which provided fixes for bugs found in the
current upstream code. Please see individual patches for
descriptions,

Steve.

[PATCH 1/4] GFS2: Fix race between lru_list and glock ref count

[Steven Whitehouse]

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 <swhiteho@redhat.com>

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 376816f..351a3e7 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);
-- 
1.7.4

[PATCH 2/4] GFS2: Read in rindex if necessary during unlink

[Steven Whitehouse]

From: Bob Peterson <rpeterso@redhat.com>

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 <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index a7d611b..c87faf4 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);
 
 
-- 
1.7.4

[PATCH 3/4] GFS2: Ensure rindex is uptodate for fallocate

[Steven Whitehouse]

From: Bob Peterson <rpeterso@redhat.com>

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 <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index c5fb359..7f906c8 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))
-- 
1.7.4

[PATCH 4/4] GFS2: Read resource groups on mount

[Steven Whitehouse]

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 <swhiteho@redhat.com>

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 7f906c8..c5fb359 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 c87faf4..5698746 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 6aacf3f..24f609c 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 981bfa3..49ada95 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);
 	}
 
-- 
1.7.4