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

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

[Steven Whitehouse]

Hi,

These are three important, but relatively small, bug fixes for GFS2.
The first prevents a kernel BUG triggering in a relatively unlikely
(but possible) scenario when a log flush caused by glock demotion
races with a log flush from some other initiator (e.g. fsync).

The second and third patches add extra conditions to two areas
of code. This makes their behaviour match ext3 in those cases,

Steve.

[Cluster-devel] [PATCH 1/3] GFS2: Rework reclaiming unlinked dinodes

[Steven Whitehouse]

From: Bob Peterson <rpeterso@redhat.com>

The previous patch I wrote for reclaiming unlinked dinodes
had some shortcomings and did not prevent all hangs.
This version is much cleaner and more logical, and has
passed very difficult testing.  Sorry for the churn.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
---
 fs/gfs2/inode.c |   54 +++++++++++++++++++++++++++++-------------------------
 fs/gfs2/inode.h |    3 +--
 fs/gfs2/log.c   |    2 +-
 fs/gfs2/log.h   |   29 +++++++++++------------------
 fs/gfs2/rgrp.c  |   20 ++++++++++++--------
 5 files changed, 54 insertions(+), 54 deletions(-)

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 51d8061..b5612cb 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -242,34 +242,38 @@ fail:
 }
 
 /**
- * gfs2_unlinked_inode_lookup - Lookup an unlinked inode for reclamation
+ * gfs2_process_unlinked_inode - Lookup an unlinked inode for reclamation
+ *                               and try to reclaim it by doing iput.
+ *
+ * This function assumes no rgrp locks are currently held.
+ *
  * @sb: The super block
  * no_addr: The inode number
- * @@inode: A pointer to the inode found, if any
  *
- * Returns: 0 and *inode if no errors occurred.  If an error occurs,
- *          the resulting *inode may or may not be NULL.
  */
 
-int gfs2_unlinked_inode_lookup(struct super_block *sb, u64 no_addr,
-			       struct inode **inode)
+void gfs2_process_unlinked_inode(struct super_block *sb, u64 no_addr)
 {
 	struct gfs2_sbd *sdp;
 	struct gfs2_inode *ip;
 	struct gfs2_glock *io_gl;
 	int error;
 	struct gfs2_holder gh;
+	struct inode *inode;
 
-	*inode = gfs2_iget_skip(sb, no_addr);
+	inode = gfs2_iget_skip(sb, no_addr);
 
-	if (!(*inode))
-		return -ENOBUFS;
+	if (!inode)
+		return;
 
-	if (!((*inode)->i_state & I_NEW))
-		return -ENOBUFS;
+	/* If it's not a new inode, someone's using it, so leave it alone. */
+	if (!(inode->i_state & I_NEW)) {
+		iput(inode);
+		return;
+	}
 
-	ip = GFS2_I(*inode);
-	sdp = GFS2_SB(*inode);
+	ip = GFS2_I(inode);
+	sdp = GFS2_SB(inode);
 	ip->i_no_formal_ino = -1;
 
 	error = gfs2_glock_get(sdp, no_addr, &gfs2_inode_glops, CREATE, &ip->i_gl);
@@ -284,15 +288,13 @@ int gfs2_unlinked_inode_lookup(struct super_block *sb, u64 no_addr,
 	set_bit(GIF_INVALID, &ip->i_flags);
 	error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, LM_FLAG_TRY | GL_EXACT,
 				   &ip->i_iopen_gh);
-	if (unlikely(error)) {
-		if (error == GLR_TRYFAILED)
-			error = 0;
+	if (unlikely(error))
 		goto fail_iopen;
-	}
+
 	ip->i_iopen_gh.gh_gl->gl_object = ip;
 	gfs2_glock_put(io_gl);
 
-	(*inode)->i_mode = DT2IF(DT_UNKNOWN);
+	inode->i_mode = DT2IF(DT_UNKNOWN);
 
 	/*
 	 * We must read the inode in order to work out its type in
@@ -303,16 +305,17 @@ int gfs2_unlinked_inode_lookup(struct super_block *sb, u64 no_addr,
 	 */
 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, LM_FLAG_TRY,
 				   &gh);
-	if (unlikely(error)) {
-		if (error == GLR_TRYFAILED)
-			error = 0;
+	if (unlikely(error))
 		goto fail_glock;
-	}
+
 	/* Inode is now uptodate */
 	gfs2_glock_dq_uninit(&gh);
-	gfs2_set_iop(*inode);
+	gfs2_set_iop(inode);
+
+	/* The iput will cause it to be deleted. */
+	iput(inode);
+	return;
 
-	return 0;
 fail_glock:
 	gfs2_glock_dq(&ip->i_iopen_gh);
 fail_iopen:
@@ -321,7 +324,8 @@ fail_put:
 	ip->i_gl->gl_object = NULL;
 	gfs2_glock_put(ip->i_gl);
 fail:
-	return error;
+	iget_failed(inode);
+	return;
 }
 
 static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
diff --git a/fs/gfs2/inode.h b/fs/gfs2/inode.h
index e161461..300ada3 100644
--- a/fs/gfs2/inode.h
+++ b/fs/gfs2/inode.h
@@ -84,8 +84,7 @@ static inline void gfs2_inum_out(const struct gfs2_inode *ip,
 extern void gfs2_set_iop(struct inode *inode);
 extern struct inode *gfs2_inode_lookup(struct super_block *sb, unsigned type, 
 				       u64 no_addr, u64 no_formal_ino);
-extern int gfs2_unlinked_inode_lookup(struct super_block *sb, u64 no_addr,
-				      struct inode **inode);
+extern void gfs2_process_unlinked_inode(struct super_block *sb, u64 no_addr);
 extern struct inode *gfs2_ilookup(struct super_block *sb, u64 no_addr);
 
 extern int gfs2_inode_refresh(struct gfs2_inode *ip);
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index b593f0e..6a857e2 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -696,7 +696,7 @@ static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
  *
  */
 
-void __gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
+void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
 {
 	struct gfs2_ail *ai;
 
diff --git a/fs/gfs2/log.h b/fs/gfs2/log.h
index eb570b4..0d007f9 100644
--- a/fs/gfs2/log.h
+++ b/fs/gfs2/log.h
@@ -47,28 +47,21 @@ static inline void gfs2_log_pointers_init(struct gfs2_sbd *sdp,
 	sdp->sd_log_head = sdp->sd_log_tail = value;
 }
 
-unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
+extern unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
 			    unsigned int ssize);
 
-int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks);
-void gfs2_log_incr_head(struct gfs2_sbd *sdp);
+extern int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks);
+extern void gfs2_log_incr_head(struct gfs2_sbd *sdp);
 
-struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp);
-struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
+extern struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp);
+extern struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
 				      struct buffer_head *real);
-void __gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl);
+extern void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl);
+extern void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *trans);
+extern void gfs2_remove_from_ail(struct gfs2_bufdata *bd);
 
-static inline void gfs2_log_flush(struct gfs2_sbd *sbd, struct gfs2_glock *gl)
-{
-	if (!gl || test_bit(GLF_LFLUSH, &gl->gl_flags))
-		__gfs2_log_flush(sbd, gl);
-}
-
-void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *trans);
-void gfs2_remove_from_ail(struct gfs2_bufdata *bd);
-
-void gfs2_log_shutdown(struct gfs2_sbd *sdp);
-void gfs2_meta_syncfs(struct gfs2_sbd *sdp);
-int gfs2_logd(void *data);
+extern void gfs2_log_shutdown(struct gfs2_sbd *sdp);
+extern void gfs2_meta_syncfs(struct gfs2_sbd *sdp);
+extern int gfs2_logd(void *data);
 
 #endif /* __LOG_DOT_H__ */
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 8bce73e..6daf4c6 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1191,7 +1191,6 @@ int gfs2_inplace_reserve_i(struct gfs2_inode *ip, char *file, unsigned int line)
 {
 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 	struct gfs2_alloc *al = ip->i_alloc;
-	struct inode *inode;
 	int error = 0;
 	u64 last_unlinked = NO_BLOCK, unlinked;
 
@@ -1209,22 +1208,27 @@ try_again:
 	if (error)
 		return error;
 
+	/* Find an rgrp suitable for allocation.  If it encounters any unlinked
+	   dinodes along the way, error will equal -EAGAIN and unlinked will
+	   contains it block address. We then need to look up that inode and
+	   try to free it, and try the allocation again. */
 	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 (error != -EAGAIN)
 			return error;
-		error = gfs2_unlinked_inode_lookup(ip->i_inode.i_sb,
-						   unlinked, &inode);
-		if (inode)
-			iput(inode);
+
+		gfs2_process_unlinked_inode(ip->i_inode.i_sb, unlinked);
+		/* regardless of whether or not gfs2_process_unlinked_inode
+		   was successful, we don't want to repeat it again. */
+		last_unlinked = unlinked;
 		gfs2_log_flush(sdp, NULL);
-		if (error == GLR_TRYFAILED)
-			error = 0;
+		error = 0;
+
 		goto try_again;
 	}
-
+	/* no error, so we have the rgrp set in the inode's allocation. */
 	al->al_file = file;
 	al->al_line = line;
 
-- 
1.6.2.5

[Cluster-devel] [PATCH 2/3] GFS2: Don't "get" xattrs for ACLs when ACLs are turned off

[Steven Whitehouse]

This is to match ext3 behaviour. We should not allow getting of
xattrs relating to ACLs when ACLs are turned off.

Reported-by: Nate Straz <nstraz@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
---
 fs/gfs2/acl.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c
index 87ee309..ca991d7 100644
--- a/fs/gfs2/acl.c
+++ b/fs/gfs2/acl.c
@@ -236,10 +236,14 @@ static int gfs2_xattr_system_get(struct dentry *dentry, const char *name,
 				 void *buffer, size_t size, int xtype)
 {
 	struct inode *inode = dentry->d_inode;
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
 	struct posix_acl *acl;
 	int type;
 	int error;
 
+	if (!sdp->sd_args.ar_posix_acl)
+		return -EOPNOTSUPP;
+
 	type = gfs2_acl_type(name);
 	if (type < 0)
 		return type;
-- 
1.6.2.5

[Cluster-devel] [PATCH 3/3] GFS2: Fix permissions checking for setflags ioctl()

[Steven Whitehouse]

We should be checking for the ownership of the file for which
flags are being set, rather than just for write access.

Reported-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
---
 fs/gfs2/file.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index e6dd2ae..b20bfcc 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -218,6 +218,11 @@ static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
 	if (error)
 		goto out_drop_write;
 
+	error = -EACCES;
+	if (!is_owner_or_cap(inode))
+		goto out;
+
+	error = 0;
 	flags = ip->i_diskflags;
 	new_flags = (flags & ~mask) | (reqflags & mask);
 	if ((new_flags ^ flags) == 0)
@@ -275,8 +280,10 @@ static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
 {
 	struct inode *inode = filp->f_path.dentry->d_inode;
 	u32 fsflags, gfsflags;
+
 	if (get_user(fsflags, ptr))
 		return -EFAULT;
+
 	gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags);
 	if (!S_ISDIR(inode->i_mode)) {
 		if (gfsflags & GFS2_DIF_INHERIT_JDATA)
-- 
1.6.2.5

[Cluster-devel] [PATCH 1/3] GFS2: Rework reclaiming unlinked dinodes

[Christoph Hellwig]

On Tue, May 25, 2010 at 09:21:27AM +0100, Steven Whitehouse wrote:
> From: Bob Peterson <rpeterso@redhat.com>
> 
> The previous patch I wrote for reclaiming unlinked dinodes
> had some shortcomings and did not prevent all hangs.
> This version is much cleaner and more logical, and has
> passed very difficult testing.  Sorry for the churn.

It would be much more helpful to have a commit message that describes
what is changed and why.  The above one won't tell anyting to someone
reading through the commit log later on.