[Cluster-devel] GFS2: Pre-pull patch posting (fixes)

[Cluster-devel] GFS2: Pre-pull patch posting (fixes)

[Steven Whitehouse]

Hi,

Here are a number of GFS2 bug fixes. There are three from Andy Price
which fix various issues spotted by automated code analysis. There are two
from Lukas Czerner fixing my mistaken assumptions as to how FITRIM
should work. Finally Ben Marzinski has fixed a bug relating to mmap and
atime and also a bug relating to a locking issue in the transaction code.

Steve.

[Cluster-devel] [PATCH 1/7] GFS2: Fix an unchecked error from gfs2_rs_alloc

[Steven Whitehouse]

From: Andrew Price <anprice@redhat.com>

Check the return value of gfs2_rs_alloc(ip) and avoid a possible null
pointer dereference.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 40c4b0d..c5af8e1 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -497,8 +497,11 @@ int gfs2_quota_hold(struct gfs2_inode *ip, u32 uid, u32 gid)
 	struct gfs2_quota_data **qd;
 	int error;
 
-	if (ip->i_res == NULL)
-		gfs2_rs_alloc(ip);
+	if (ip->i_res == NULL) {
+		error = gfs2_rs_alloc(ip);
+		if (error)
+			return error;
+	}
 
 	qd = ip->i_res->rs_qa_qd;
 
-- 
1.7.4

[Cluster-devel] [PATCH 2/7] GFS2: Fix possible null pointer deref in gfs2_rs_alloc

[Steven Whitehouse]

From: Andrew Price <anprice@redhat.com>

Despite the return value from kmem_cache_zalloc() being checked, the
error wasn't being returned until after a possible null pointer
dereference. This patch returns the error immediately, allowing the
removal of the error variable.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 3cc402c..43d1a20 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -553,7 +553,6 @@ void gfs2_free_clones(struct gfs2_rgrpd *rgd)
  */
 int gfs2_rs_alloc(struct gfs2_inode *ip)
 {
-	int error = 0;
 	struct gfs2_blkreserv *res;
 
 	if (ip->i_res)
@@ -561,7 +560,7 @@ int gfs2_rs_alloc(struct gfs2_inode *ip)
 
 	res = kmem_cache_zalloc(gfs2_rsrv_cachep, GFP_NOFS);
 	if (!res)
-		error = -ENOMEM;
+		return -ENOMEM;
 
 	RB_CLEAR_NODE(&res->rs_node);
 
@@ -571,7 +570,7 @@ int gfs2_rs_alloc(struct gfs2_inode *ip)
 	else
 		ip->i_res = res;
 	up_write(&ip->i_rw_mutex);
-	return error;
+	return 0;
 }
 
 static void dump_rs(struct seq_file *seq, const struct gfs2_blkreserv *rs)
-- 
1.7.4

[Cluster-devel] [PATCH 3/7] GFS2: Clean up some unused assignments

[Steven Whitehouse]

From: Andrew Price <anprice@redhat.com>

Cleans up two cases where variables were assigned values but then never
used again.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 0def050..377a68d 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -677,10 +677,8 @@ static ssize_t gfs2_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 	size_t writesize = iov_length(iov, nr_segs);
 	struct dentry *dentry = file->f_dentry;
 	struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
-	struct gfs2_sbd *sdp;
 	int ret;
 
-	sdp = GFS2_SB(file->f_mapping->host);
 	ret = gfs2_rs_alloc(ip);
 	if (ret)
 		return ret;
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 8ff95a2..01e444b 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -621,7 +621,6 @@ static void revoke_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 
 static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
 {
-	struct gfs2_log_descriptor *ld;
 	struct gfs2_meta_header *mh;
 	unsigned int offset;
 	struct list_head *head = &sdp->sd_log_le_revoke;
@@ -634,7 +633,6 @@ static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
 
 	length = gfs2_struct2blk(sdp, sdp->sd_log_num_revoke, sizeof(u64));
 	page = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_REVOKE, length, sdp->sd_log_num_revoke);
-	ld = page_address(page);
 	offset = sizeof(struct gfs2_log_descriptor);
 
 	list_for_each_entry(bd, head, bd_list) {
-- 
1.7.4

[Cluster-devel] [PATCH 4/7] GFS2: Require user to provide argument for FITRIM

[Steven Whitehouse]

From: Lukas Czerner <lczerner@redhat.com>

When the fstrim_range argument is not provided by user in FITRIM ioctl
we should just return EFAULT and not promoting bad behaviour by filling
the structure in kernel. Let the user deal with it.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 43d1a20..b6bbf71 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1270,11 +1270,7 @@ int gfs2_fitrim(struct file *filp, void __user *argp)
 	if (!blk_queue_discard(q))
 		return -EOPNOTSUPP;
 
-	if (argp == NULL) {
-		r.start = 0;
-		r.len = ULLONG_MAX;
-		r.minlen = 0;
-	} else if (copy_from_user(&r, argp, sizeof(r)))
+	if (copy_from_user(&r, argp, sizeof(r)))
 		return -EFAULT;
 
 	ret = gfs2_rindex_update(sdp);
@@ -1323,7 +1319,7 @@ int gfs2_fitrim(struct file *filp, void __user *argp)
 
 out:
 	r.len = trimmed << 9;
-	if (argp && copy_to_user(argp, &r, sizeof(r)))
+	if (copy_to_user(argp, &r, sizeof(r)))
 		return -EFAULT;
 
 	return ret;
-- 
1.7.4

[Cluster-devel] [PATCH 5/7] GFS2: Fix FITRIM argument handling

[Steven Whitehouse]

From: Lukas Czerner <lczerner@redhat.com>

Currently implementation in gfs2 uses FITRIM arguments as it were in
file system blocks units which is wrong. The FITRIM arguments
(fstrim_range.start, fstrim_range.len and fstrim_range.minlen) are
actually in bytes.

Moreover, check for start argument beyond the end of file system, len
argument being smaller than file system block and minlen argument being
bigger than biggest resource group were missing.

This commit converts the code to convert FITRIM argument to file system
blocks and also adds appropriate checks mentioned above.

All the problems were recognised by xfstests 251 and 260.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index b6bbf71..38fe18f 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1262,7 +1262,9 @@ int gfs2_fitrim(struct file *filp, void __user *argp)
 	int ret = 0;
 	u64 amt;
 	u64 trimmed = 0;
+	u64 start, end, minlen;
 	unsigned int x;
+	unsigned bs_shift = sdp->sd_sb.sb_bsize_shift;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
@@ -1277,8 +1279,18 @@ int gfs2_fitrim(struct file *filp, void __user *argp)
 	if (ret)
 		return ret;
 
-	rgd = gfs2_blk2rgrpd(sdp, r.start, 0);
-	rgd_end = gfs2_blk2rgrpd(sdp, r.start + r.len, 0);
+	start = r.start >> bs_shift;
+	end = start + (r.len >> bs_shift);
+	minlen = max_t(u64, r.minlen,
+		       q->limits.discard_granularity) >> bs_shift;
+
+	rgd = gfs2_blk2rgrpd(sdp, start, 0);
+	rgd_end = gfs2_blk2rgrpd(sdp, end - 1, 0);
+
+	if (end <= start ||
+	    minlen > sdp->sd_max_rg_data ||
+	    start > rgd_end->rd_data0 + rgd_end->rd_data)
+		return -EINVAL;
 
 	while (1) {
 
@@ -1290,7 +1302,9 @@ int gfs2_fitrim(struct file *filp, void __user *argp)
 			/* Trim each bitmap in the rgrp */
 			for (x = 0; x < rgd->rd_length; x++) {
 				struct gfs2_bitmap *bi = rgd->rd_bits + x;
-				ret = gfs2_rgrp_send_discards(sdp, rgd->rd_data0, NULL, bi, r.minlen, &amt);
+				ret = gfs2_rgrp_send_discards(sdp,
+						rgd->rd_data0, NULL, bi, minlen,
+						&amt);
 				if (ret) {
 					gfs2_glock_dq_uninit(&gh);
 					goto out;
-- 
1.7.4

[Cluster-devel] [PATCH 6/7] GFS2: Don't call file_accessed() with a shared glock

[Steven Whitehouse]

From: Benjamin Marzinski <bmarzins@redhat.com>

file_accessed() was being called by gfs2_mmap() with a shared glock. If it
needed to update the atime, it was crashing because it dirtied the inode in
gfs2_dirty_inode() without holding an exclusive lock. gfs2_dirty_inode()
checked if the caller was already holding a glock, but it didn't make sure that
the glock was in the exclusive state. Now, instead of calling file_accessed()
while holding the shared lock in gfs2_mmap(), file_accessed() is called after
grabbing and releasing the glock to update the inode.  If file_accessed() needs
to update the atime, it will grab an exclusive lock in gfs2_dirty_inode().

gfs2_dirty_inode() now also checks to make sure that if the calling process has
already locked the glock, it has an exclusive lock.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 377a68d..e056b4c 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -516,15 +516,13 @@ static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
 		struct gfs2_holder i_gh;
 		int error;
 
-		gfs2_holder_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
-		error = gfs2_glock_nq(&i_gh);
-		if (error == 0) {
-			file_accessed(file);
-			gfs2_glock_dq(&i_gh);
-		}
-		gfs2_holder_uninit(&i_gh);
+		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
+					   &i_gh);
 		if (error)
 			return error;
+		/* grab lock to update inode */
+		gfs2_glock_dq_uninit(&i_gh);
+		file_accessed(file);
 	}
 	vma->vm_ops = &gfs2_vm_ops;
 
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index bc73726..d648867 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -810,7 +810,8 @@ static void gfs2_dirty_inode(struct inode *inode, int flags)
 			return;
 		}
 		need_unlock = 1;
-	}
+	} else if (WARN_ON_ONCE(ip->i_gl->gl_state != LM_ST_EXCLUSIVE))
+		return;
 
 	if (current->journal_info == NULL) {
 		ret = gfs2_trans_begin(sdp, RES_DINODE, 0);
-- 
1.7.4

[Cluster-devel] [PATCH 7/7] GFS2: Test bufdata with buffer locked and gfs2_log_lock held

[Steven Whitehouse]

From: Benjamin Marzinski <bmarzins@redhat.com>

In gfs2_trans_add_bh(), gfs2 was testing if a there was a bd attached to the
buffer without having the gfs2_log_lock held. It was then assuming it would
stay attached for the rest of the function. However, without either the log
lock being held of the buffer locked, __gfs2_ail_flush() could detach bd at any
time.  This patch moves the locking before the test.  If there isn't a bd
already attached, gfs2 can safely allocate one and attach it before locking.
There is no way that the newly allocated bd could be on the ail list,
and thus no way for __gfs2_ail_flush() to detach it.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 01e444b..9ceccb1 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -393,12 +393,10 @@ static void buf_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 	struct gfs2_meta_header *mh;
 	struct gfs2_trans *tr;
 
-	lock_buffer(bd->bd_bh);
-	gfs2_log_lock(sdp);
 	tr = current->journal_info;
 	tr->tr_touched = 1;
 	if (!list_empty(&bd->bd_list))
-		goto out;
+		return;
 	set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
 	set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
 	mh = (struct gfs2_meta_header *)bd->bd_bh->b_data;
@@ -414,9 +412,6 @@ static void buf_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 	sdp->sd_log_num_buf++;
 	list_add(&bd->bd_list, &sdp->sd_log_le_buf);
 	tr->tr_num_buf_new++;
-out:
-	gfs2_log_unlock(sdp);
-	unlock_buffer(bd->bd_bh);
 }
 
 static void gfs2_check_magic(struct buffer_head *bh)
@@ -775,12 +770,10 @@ static void databuf_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 	struct address_space *mapping = bd->bd_bh->b_page->mapping;
 	struct gfs2_inode *ip = GFS2_I(mapping->host);
 
-	lock_buffer(bd->bd_bh);
-	gfs2_log_lock(sdp);
 	if (tr)
 		tr->tr_touched = 1;
 	if (!list_empty(&bd->bd_list))
-		goto out;
+		return;
 	set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
 	set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
 	if (gfs2_is_jdata(ip)) {
@@ -791,9 +784,6 @@ static void databuf_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 	} else {
 		list_add_tail(&bd->bd_list, &sdp->sd_log_le_ordered);
 	}
-out:
-	gfs2_log_unlock(sdp);
-	unlock_buffer(bd->bd_bh);
 }
 
 /**
diff --git a/fs/gfs2/trans.c b/fs/gfs2/trans.c
index adbd278..4136270 100644
--- a/fs/gfs2/trans.c
+++ b/fs/gfs2/trans.c
@@ -155,14 +155,22 @@ void gfs2_trans_add_bh(struct gfs2_glock *gl, struct buffer_head *bh, int meta)
 	struct gfs2_sbd *sdp = gl->gl_sbd;
 	struct gfs2_bufdata *bd;
 
+	lock_buffer(bh);
+	gfs2_log_lock(sdp);
 	bd = bh->b_private;
 	if (bd)
 		gfs2_assert(sdp, bd->bd_gl == gl);
 	else {
+		gfs2_log_unlock(sdp);
+		unlock_buffer(bh);
 		gfs2_attach_bufdata(gl, bh, meta);
 		bd = bh->b_private;
+		lock_buffer(bh);
+		gfs2_log_lock(sdp);
 	}
 	lops_add(sdp, bd);
+	gfs2_log_unlock(sdp);
+	unlock_buffer(bh);
 }
 
 void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
-- 
1.7.4