[patch v3 0/3] reiserfs locking patchset v3

[patch v3 0/3] reiserfs locking patchset v3

[Jeff Mahoney]

This patchset untangles some of the locking in reiserfs. It has seen more
testing as part of the maintenance cycle in SLE 11 SP2.

- We push the write lock out of the xattr code. It doesn't need it and
  we can simplify locking by releasing and reacquiring the locks around
  the xattr calls.

- Handle nested locks properly. There's confusion on when a lock is nested,
  when it's not, and how to drop it across schedules like the BKL it is
  modeled after. We make the distinction between taking/releasing the lock
  and when to drop it for schedules and simplify the logic. This fixes
  a number of deadlocks that happen because the intention was to drop
  the write lock but it really only decremented the use count.

- Fix the deadlocks with the quota code. This involves dropping the write
  lock before quota calls and reacquring it afterwards. Without this patch
  reiserfs quotas are essentially unusable.

Previous postings of this patchset were mismerged.

Jan - This series is in the for-3.12 branch of
git.kernel.org:/pub/scm/linux/kernel/git/jeffm/linux-reiserfs.git

Thanks.

-Jeff

[patch v3 1/3] reiserfs: locking, push write lock out of xattr code

[Jeff Mahoney]

[-- Attachment #1: reiserfs/reiserfs-locking-push-write-lock-out-of-xattr-code --]
[-- Type: text/plain, Size: 16877 bytes --]

The reiserfs xattr code doesn't need the write lock and sleeps all over
the place. We can simplify the locking by releasing it and reacquiring
after the xattr call.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
---
 fs/reiserfs/inode.c     |   38 ++++++++++++++++++++------------------
 fs/reiserfs/super.c     |   48 +++++++++++++++++++++++-------------------------
 fs/reiserfs/xattr.c     |   46 +++++++++++++++++-----------------------------
 fs/reiserfs/xattr_acl.c |   16 ++++++++++------
 4 files changed, 70 insertions(+), 78 deletions(-)

--- a/fs/reiserfs/inode.c	2013-08-07 10:23:30.681636170 -0400
+++ b/fs/reiserfs/inode.c	2013-08-07 10:23:31.613622029 -0400
@@ -30,7 +30,6 @@ void reiserfs_evict_inode(struct inode *
 	    JOURNAL_PER_BALANCE_CNT * 2 +
 	    2 * REISERFS_QUOTA_INIT_BLOCKS(inode->i_sb);
 	struct reiserfs_transaction_handle th;
-	int depth;
 	int err;
 
 	if (!inode->i_nlink && !is_bad_inode(inode))
@@ -40,12 +39,14 @@ void reiserfs_evict_inode(struct inode *
 	if (inode->i_nlink)
 		goto no_delete;
 
-	depth = reiserfs_write_lock_once(inode->i_sb);
-
 	/* The = 0 happens when we abort creating a new inode for some reason like lack of space.. */
 	if (!(inode->i_state & I_NEW) && INODE_PKEY(inode)->k_objectid != 0) {	/* also handles bad_inode case */
+		int depth;
+
 		reiserfs_delete_xattrs(inode);
 
+		depth = reiserfs_write_lock_once(inode->i_sb);
+
 		if (journal_begin(&th, inode->i_sb, jbegin_count))
 			goto out;
 		reiserfs_update_inode_transaction(inode);
@@ -72,12 +73,12 @@ void reiserfs_evict_inode(struct inode *
 		/* all items of file are deleted, so we can remove "save" link */
 		remove_save_link(inode, 0 /* not truncate */ );	/* we can't do anything
 								 * about an error here */
+out:
+		reiserfs_write_unlock_once(inode->i_sb, depth);
 	} else {
 		/* no object items are in the tree */
 		;
 	}
-      out:
-	reiserfs_write_unlock_once(inode->i_sb, depth);
 	clear_inode(inode);	/* note this must go after the journal_end to prevent deadlock */
 	dquot_drop(inode);
 	inode->i_blocks = 0;
@@ -1941,7 +1942,9 @@ int reiserfs_new_inode(struct reiserfs_t
 	}
 
 	if (reiserfs_posixacl(inode->i_sb)) {
+		reiserfs_write_unlock(inode->i_sb);
 		retval = reiserfs_inherit_default_acl(th, dir, dentry, inode);
+		reiserfs_write_lock(inode->i_sb);
 		if (retval) {
 			err = retval;
 			reiserfs_check_path(&path_to_key);
@@ -1956,7 +1959,9 @@ int reiserfs_new_inode(struct reiserfs_t
 		inode->i_flags |= S_PRIVATE;
 
 	if (security->name) {
+		reiserfs_write_unlock(inode->i_sb);
 		retval = reiserfs_security_write(th, inode, security);
+		reiserfs_write_lock(inode->i_sb);
 		if (retval) {
 			err = retval;
 			reiserfs_check_path(&path_to_key);
@@ -3129,6 +3134,7 @@ int reiserfs_setattr(struct dentry *dent
 		 */
 		if (get_inode_item_key_version(inode) == KEY_FORMAT_3_5 &&
 		    attr->ia_size > MAX_NON_LFS) {
+			reiserfs_write_unlock_once(inode->i_sb, depth);
 			error = -EFBIG;
 			goto out;
 		}
@@ -3150,8 +3156,10 @@ int reiserfs_setattr(struct dentry *dent
 				if (err)
 					error = err;
 			}
-			if (error)
+			if (error) {
+				reiserfs_write_unlock_once(inode->i_sb, depth);
 				goto out;
+			}
 			/*
 			 * file size is changed, ctime and mtime are
 			 * to be updated
@@ -3159,6 +3167,7 @@ int reiserfs_setattr(struct dentry *dent
 			attr->ia_valid |= (ATTR_MTIME | ATTR_CTIME);
 		}
 	}
+	reiserfs_write_unlock_once(inode->i_sb, depth);
 
 	if ((((attr->ia_valid & ATTR_UID) && (from_kuid(&init_user_ns, attr->ia_uid) & ~0xffff)) ||
 	     ((attr->ia_valid & ATTR_GID) && (from_kgid(&init_user_ns, attr->ia_gid) & ~0xffff))) &&
@@ -3183,14 +3192,16 @@ int reiserfs_setattr(struct dentry *dent
 			return error;
 
 		/* (user+group)*(old+new) structure - we count quota info and , inode write (sb, inode) */
+		depth = reiserfs_write_lock_once(inode->i_sb);
 		error = journal_begin(&th, inode->i_sb, jbegin_count);
+		reiserfs_write_unlock_once(inode->i_sb, depth);
 		if (error)
 			goto out;
-		reiserfs_write_unlock_once(inode->i_sb, depth);
 		error = dquot_transfer(inode, attr);
 		depth = reiserfs_write_lock_once(inode->i_sb);
 		if (error) {
 			journal_end(&th, inode->i_sb, jbegin_count);
+			reiserfs_write_unlock_once(inode->i_sb, depth);
 			goto out;
 		}
 
@@ -3202,17 +3213,11 @@ int reiserfs_setattr(struct dentry *dent
 			inode->i_gid = attr->ia_gid;
 		mark_inode_dirty(inode);
 		error = journal_end(&th, inode->i_sb, jbegin_count);
+		reiserfs_write_unlock_once(inode->i_sb, depth);
 		if (error)
 			goto out;
 	}
 
-	/*
-	 * Relax the lock here, as it might truncate the
-	 * inode pages and wait for inode pages locks.
-	 * To release such page lock, the owner needs the
-	 * reiserfs lock
-	 */
-	reiserfs_write_unlock_once(inode->i_sb, depth);
 	if ((attr->ia_valid & ATTR_SIZE) &&
 	    attr->ia_size != i_size_read(inode)) {
 		error = inode_newsize_ok(inode, attr->ia_size);
@@ -3226,16 +3231,13 @@ int reiserfs_setattr(struct dentry *dent
 		setattr_copy(inode, attr);
 		mark_inode_dirty(inode);
 	}
-	depth = reiserfs_write_lock_once(inode->i_sb);
 
 	if (!error && reiserfs_posixacl(inode->i_sb)) {
 		if (attr->ia_valid & ATTR_MODE)
 			error = reiserfs_acl_chmod(inode);
 	}
 
-      out:
-	reiserfs_write_unlock_once(inode->i_sb, depth);
-
+out:
 	return error;
 }
 
--- a/fs/reiserfs/super.c	2013-08-07 10:23:30.681636170 -0400
+++ b/fs/reiserfs/super.c	2013-08-07 10:23:31.637621664 -0400
@@ -1335,7 +1335,7 @@ static int reiserfs_remount(struct super
 				kfree(qf_names[i]);
 #endif
 		err = -EINVAL;
-		goto out_unlock;
+		goto out_err_unlock;
 	}
 #ifdef CONFIG_QUOTA
 	handle_quota_files(s, qf_names, &qfmt);
@@ -1379,35 +1379,32 @@ static int reiserfs_remount(struct super
 	if (blocks) {
 		err = reiserfs_resize(s, blocks);
 		if (err != 0)
-			goto out_unlock;
+			goto out_err_unlock;
 	}
 
 	if (*mount_flags & MS_RDONLY) {
+		reiserfs_write_unlock(s);
 		reiserfs_xattr_init(s, *mount_flags);
 		/* remount read-only */
 		if (s->s_flags & MS_RDONLY)
 			/* it is read-only already */
-			goto out_ok;
+			goto out_ok_unlocked;
 
-		/*
-		 * Drop write lock. Quota will retake it when needed and lock
-		 * ordering requires calling dquot_suspend() without it.
-		 */
-		reiserfs_write_unlock(s);
 		err = dquot_suspend(s, -1);
 		if (err < 0)
 			goto out_err;
-		reiserfs_write_lock(s);
 
 		/* try to remount file system with read-only permissions */
 		if (sb_umount_state(rs) == REISERFS_VALID_FS
 		    || REISERFS_SB(s)->s_mount_state != REISERFS_VALID_FS) {
-			goto out_ok;
+			goto out_ok_unlocked;
 		}
 
+		reiserfs_write_lock(s);
+
 		err = journal_begin(&th, s, 10);
 		if (err)
-			goto out_unlock;
+			goto out_err_unlock;
 
 		/* Mounting a rw partition read-only. */
 		reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
@@ -1416,13 +1413,14 @@ static int reiserfs_remount(struct super
 	} else {
 		/* remount read-write */
 		if (!(s->s_flags & MS_RDONLY)) {
+			reiserfs_write_unlock(s);
 			reiserfs_xattr_init(s, *mount_flags);
-			goto out_ok;	/* We are read-write already */
+			goto out_ok_unlocked;	/* We are read-write already */
 		}
 
 		if (reiserfs_is_journal_aborted(journal)) {
 			err = journal->j_errno;
-			goto out_unlock;
+			goto out_err_unlock;
 		}
 
 		handle_data_mode(s, mount_options);
@@ -1431,7 +1429,7 @@ static int reiserfs_remount(struct super
 		s->s_flags &= ~MS_RDONLY;	/* now it is safe to call journal_begin */
 		err = journal_begin(&th, s, 10);
 		if (err)
-			goto out_unlock;
+			goto out_err_unlock;
 
 		/* Mount a partition which is read-only, read-write */
 		reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
@@ -1448,26 +1446,22 @@ static int reiserfs_remount(struct super
 	SB_JOURNAL(s)->j_must_wait = 1;
 	err = journal_end(&th, s, 10);
 	if (err)
-		goto out_unlock;
+		goto out_err_unlock;
 
+	reiserfs_write_unlock(s);
 	if (!(*mount_flags & MS_RDONLY)) {
-		/*
-		 * Drop write lock. Quota will retake it when needed and lock
-		 * ordering requires calling dquot_resume() without it.
-		 */
-		reiserfs_write_unlock(s);
 		dquot_resume(s, -1);
 		reiserfs_write_lock(s);
 		finish_unfinished(s);
+		reiserfs_write_unlock(s);
 		reiserfs_xattr_init(s, *mount_flags);
 	}
 
-out_ok:
+out_ok_unlocked:
 	replace_mount_options(s, new_opts);
-	reiserfs_write_unlock(s);
 	return 0;
 
-out_unlock:
+out_err_unlock:
 	reiserfs_write_unlock(s);
 out_err:
 	kfree(new_opts);
@@ -2014,12 +2008,14 @@ static int reiserfs_fill_super(struct su
 			goto error;
 		}
 
+		reiserfs_write_unlock(s);
 		if ((errval = reiserfs_lookup_privroot(s)) ||
 		    (errval = reiserfs_xattr_init(s, s->s_flags))) {
 			dput(s->s_root);
 			s->s_root = NULL;
-			goto error;
+			goto error_unlocked;
 		}
+		reiserfs_write_lock(s);
 
 		/* look for files which were to be removed in previous session */
 		finish_unfinished(s);
@@ -2028,12 +2024,14 @@ static int reiserfs_fill_super(struct su
 			reiserfs_info(s, "using 3.5.x disk format\n");
 		}
 
+		reiserfs_write_unlock(s);
 		if ((errval = reiserfs_lookup_privroot(s)) ||
 		    (errval = reiserfs_xattr_init(s, s->s_flags))) {
 			dput(s->s_root);
 			s->s_root = NULL;
-			goto error;
+			goto error_unlocked;
 		}
+		reiserfs_write_lock(s);
 	}
 	// mark hash in super block: it could be unset. overwrite should be ok
 	set_sb_hash_function_code(rs, function2code(sbi->s_hash_function));
--- a/fs/reiserfs/xattr.c	2013-08-07 10:23:30.681636170 -0400
+++ b/fs/reiserfs/xattr.c	2013-08-07 10:23:31.649621482 -0400
@@ -81,8 +81,7 @@ static int xattr_unlink(struct inode *di
 	int error;
 	BUG_ON(!mutex_is_locked(&dir->i_mutex));
 
-	reiserfs_mutex_lock_nested_safe(&dentry->d_inode->i_mutex,
-					I_MUTEX_CHILD, dir->i_sb);
+	mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
 	error = dir->i_op->unlink(dir, dentry);
 	mutex_unlock(&dentry->d_inode->i_mutex);
 
@@ -96,8 +95,7 @@ static int xattr_rmdir(struct inode *dir
 	int error;
 	BUG_ON(!mutex_is_locked(&dir->i_mutex));
 
-	reiserfs_mutex_lock_nested_safe(&dentry->d_inode->i_mutex,
-					I_MUTEX_CHILD, dir->i_sb);
+	mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
 	error = dir->i_op->rmdir(dir, dentry);
 	if (!error)
 		dentry->d_inode->i_flags |= S_DEAD;
@@ -232,22 +230,17 @@ static int reiserfs_for_each_xattr(struc
 	if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
 		return 0;
 
-	reiserfs_write_unlock(inode->i_sb);
 	dir = open_xa_dir(inode, XATTR_REPLACE);
 	if (IS_ERR(dir)) {
 		err = PTR_ERR(dir);
-		reiserfs_write_lock(inode->i_sb);
 		goto out;
 	} else if (!dir->d_inode) {
 		err = 0;
-		reiserfs_write_lock(inode->i_sb);
 		goto out_dir;
 	}
 
 	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
 
-	reiserfs_write_lock(inode->i_sb);
-
 	buf.xadir = dir;
 	while (1) {
 		err = reiserfs_readdir_inode(dir->d_inode, &buf.ctx);
@@ -281,14 +274,17 @@ static int reiserfs_for_each_xattr(struc
 		int blocks = JOURNAL_PER_BALANCE_CNT * 2 + 2 +
 			     4 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb);
 		struct reiserfs_transaction_handle th;
+		reiserfs_write_lock(inode->i_sb);
 		err = journal_begin(&th, inode->i_sb, blocks);
+		reiserfs_write_unlock(inode->i_sb);
 		if (!err) {
 			int jerror;
-			reiserfs_mutex_lock_nested_safe(
-					  &dir->d_parent->d_inode->i_mutex,
-					  I_MUTEX_XATTR, inode->i_sb);
+			mutex_lock_nested(&dir->d_parent->d_inode->i_mutex,
+					  I_MUTEX_XATTR);
 			err = action(dir, data);
+			reiserfs_write_lock(inode->i_sb);
 			jerror = journal_end(&th, inode->i_sb, blocks);
+			reiserfs_write_unlock(inode->i_sb);
 			mutex_unlock(&dir->d_parent->d_inode->i_mutex);
 			err = jerror ?: err;
 		}
@@ -455,9 +451,7 @@ static int lookup_and_delete_xattr(struc
 	}
 
 	if (dentry->d_inode) {
-		reiserfs_write_lock(inode->i_sb);
 		err = xattr_unlink(xadir->d_inode, dentry);
-		reiserfs_write_unlock(inode->i_sb);
 		update_ctime(inode);
 	}
 
@@ -491,24 +485,17 @@ reiserfs_xattr_set_handle(struct reiserf
 	if (get_inode_sd_version(inode) == STAT_DATA_V1)
 		return -EOPNOTSUPP;
 
-	reiserfs_write_unlock(inode->i_sb);
-
 	if (!buffer) {
 		err = lookup_and_delete_xattr(inode, name);
-		reiserfs_write_lock(inode->i_sb);
 		return err;
 	}
 
 	dentry = xattr_lookup(inode, name, flags);
-	if (IS_ERR(dentry)) {
-		reiserfs_write_lock(inode->i_sb);
+	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
-	}
 
 	down_write(&REISERFS_I(inode)->i_xattr_sem);
 
-	reiserfs_write_lock(inode->i_sb);
-
 	xahash = xattr_hash(buffer, buffer_size);
 	while (buffer_pos < buffer_size || buffer_pos == 0) {
 		size_t chunk;
@@ -538,6 +525,7 @@ reiserfs_xattr_set_handle(struct reiserf
 			rxh->h_hash = cpu_to_le32(xahash);
 		}
 
+		reiserfs_write_lock(inode->i_sb);
 		err = __reiserfs_write_begin(page, page_offset, chunk + skip);
 		if (!err) {
 			if (buffer)
@@ -546,6 +534,7 @@ reiserfs_xattr_set_handle(struct reiserf
 						    page_offset + chunk +
 						    skip);
 		}
+		reiserfs_write_unlock(inode->i_sb);
 		unlock_page(page);
 		reiserfs_put_page(page);
 		buffer_pos += chunk;
@@ -563,10 +552,8 @@ reiserfs_xattr_set_handle(struct reiserf
 			.ia_valid = ATTR_SIZE | ATTR_CTIME,
 		};
 
-		reiserfs_write_unlock(inode->i_sb);
 		mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
 		inode_dio_wait(dentry->d_inode);
-		reiserfs_write_lock(inode->i_sb);
 
 		err = reiserfs_setattr(dentry, &newattrs);
 		mutex_unlock(&dentry->d_inode->i_mutex);
@@ -592,18 +579,19 @@ int reiserfs_xattr_set(struct inode *ino
 
 	reiserfs_write_lock(inode->i_sb);
 	error = journal_begin(&th, inode->i_sb, jbegin_count);
+	reiserfs_write_unlock(inode->i_sb);
 	if (error) {
-		reiserfs_write_unlock(inode->i_sb);
 		return error;
 	}
 
 	error = reiserfs_xattr_set_handle(&th, inode, name,
 					  buffer, buffer_size, flags);
 
+	reiserfs_write_lock(inode->i_sb);
 	error2 = journal_end(&th, inode->i_sb, jbegin_count);
+	reiserfs_write_unlock(inode->i_sb);
 	if (error == 0)
 		error = error2;
-	reiserfs_write_unlock(inode->i_sb);
 
 	return error;
 }
@@ -968,7 +956,7 @@ int reiserfs_lookup_privroot(struct supe
 	int err = 0;
 
 	/* If we don't have the privroot located yet - go find it */
-	reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
+	mutex_lock(&s->s_root->d_inode->i_mutex);
 	dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
 				strlen(PRIVROOT_NAME));
 	if (!IS_ERR(dentry)) {
@@ -996,14 +984,14 @@ int reiserfs_xattr_init(struct super_blo
 		goto error;
 
 	if (!privroot->d_inode && !(mount_flags & MS_RDONLY)) {
-		reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
+		mutex_lock(&s->s_root->d_inode->i_mutex);
 		err = create_privroot(REISERFS_SB(s)->priv_root);
 		mutex_unlock(&s->s_root->d_inode->i_mutex);
 	}
 
 	if (privroot->d_inode) {
 		s->s_xattr = reiserfs_xattr_handlers;
-		reiserfs_mutex_lock_safe(&privroot->d_inode->i_mutex, s);
+		mutex_lock(&privroot->d_inode->i_mutex);
 		if (!REISERFS_SB(s)->xattr_root) {
 			struct dentry *dentry;
 			dentry = lookup_one_len(XAROOT_NAME, privroot,
--- a/fs/reiserfs/xattr_acl.c	2013-08-07 10:23:30.681636170 -0400
+++ b/fs/reiserfs/xattr_acl.c	2013-08-07 10:23:31.661621300 -0400
@@ -49,13 +49,15 @@ posix_acl_set(struct dentry *dentry, con
 
 	reiserfs_write_lock(inode->i_sb);
 	error = journal_begin(&th, inode->i_sb, jcreate_blocks);
+	reiserfs_write_unlock(inode->i_sb);
 	if (error == 0) {
 		error = reiserfs_set_acl(&th, inode, type, acl);
+		reiserfs_write_lock(inode->i_sb);
 		error2 = journal_end(&th, inode->i_sb, jcreate_blocks);
+		reiserfs_write_unlock(inode->i_sb);
 		if (error2)
 			error = error2;
 	}
-	reiserfs_write_unlock(inode->i_sb);
 
       release_and_out:
 	posix_acl_release(acl);
@@ -435,12 +437,14 @@ int reiserfs_cache_default_acl(struct in
 	return nblocks;
 }
 
+/*
+ * Called under i_mutex
+ */
 int reiserfs_acl_chmod(struct inode *inode)
 {
 	struct reiserfs_transaction_handle th;
 	struct posix_acl *acl;
 	size_t size;
-	int depth;
 	int error;
 
 	if (IS_PRIVATE(inode))
@@ -454,9 +458,7 @@ int reiserfs_acl_chmod(struct inode *ino
 		return 0;
 	}
 
-	reiserfs_write_unlock(inode->i_sb);
 	acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
-	reiserfs_write_lock(inode->i_sb);
 	if (!acl)
 		return 0;
 	if (IS_ERR(acl))
@@ -466,16 +468,18 @@ int reiserfs_acl_chmod(struct inode *ino
 		return error;
 
 	size = reiserfs_xattr_nblocks(inode, reiserfs_acl_size(acl->a_count));
-	depth = reiserfs_write_lock_once(inode->i_sb);
+	reiserfs_write_lock(inode->i_sb);
 	error = journal_begin(&th, inode->i_sb, size * 2);
+	reiserfs_write_unlock(inode->i_sb);
 	if (!error) {
 		int error2;
 		error = reiserfs_set_acl(&th, inode, ACL_TYPE_ACCESS, acl);
+		reiserfs_write_lock(inode->i_sb);
 		error2 = journal_end(&th, inode->i_sb, size * 2);
+		reiserfs_write_unlock(inode->i_sb);
 		if (error2)
 			error = error2;
 	}
-	reiserfs_write_unlock_once(inode->i_sb, depth);
 	posix_acl_release(acl);
 	return error;
 }

Re: [patch v3 1/3] reiserfs: locking, push write lock out of xattr code

[Jan Kara]

On Wed 07-08-13 12:35:16, Jeff Mahoney wrote:
> The reiserfs xattr code doesn't need the write lock and sleeps all over
> the place. We can simplify the locking by releasing it and reacquiring
> after the xattr call.
  The patch looks good so I'll merge it once comment to patch 2/3 gets
sorted out.

								Honza

> 
> Signed-off-by: Jeff Mahoney <jeffm@suse.com>
> ---
>  fs/reiserfs/inode.c     |   38 ++++++++++++++++++++------------------
>  fs/reiserfs/super.c     |   48 +++++++++++++++++++++++-------------------------
>  fs/reiserfs/xattr.c     |   46 +++++++++++++++++-----------------------------
>  fs/reiserfs/xattr_acl.c |   16 ++++++++++------
>  4 files changed, 70 insertions(+), 78 deletions(-)
> 
> --- a/fs/reiserfs/inode.c	2013-08-07 10:23:30.681636170 -0400
> +++ b/fs/reiserfs/inode.c	2013-08-07 10:23:31.613622029 -0400
> @@ -30,7 +30,6 @@ void reiserfs_evict_inode(struct inode *
>  	    JOURNAL_PER_BALANCE_CNT * 2 +
>  	    2 * REISERFS_QUOTA_INIT_BLOCKS(inode->i_sb);
>  	struct reiserfs_transaction_handle th;
> -	int depth;
>  	int err;
>  
>  	if (!inode->i_nlink && !is_bad_inode(inode))
> @@ -40,12 +39,14 @@ void reiserfs_evict_inode(struct inode *
>  	if (inode->i_nlink)
>  		goto no_delete;
>  
> -	depth = reiserfs_write_lock_once(inode->i_sb);
> -
>  	/* The = 0 happens when we abort creating a new inode for some reason like lack of space.. */
>  	if (!(inode->i_state & I_NEW) && INODE_PKEY(inode)->k_objectid != 0) {	/* also handles bad_inode case */
> +		int depth;
> +
>  		reiserfs_delete_xattrs(inode);
>  
> +		depth = reiserfs_write_lock_once(inode->i_sb);
> +
>  		if (journal_begin(&th, inode->i_sb, jbegin_count))
>  			goto out;
>  		reiserfs_update_inode_transaction(inode);
> @@ -72,12 +73,12 @@ void reiserfs_evict_inode(struct inode *
>  		/* all items of file are deleted, so we can remove "save" link */
>  		remove_save_link(inode, 0 /* not truncate */ );	/* we can't do anything
>  								 * about an error here */
> +out:
> +		reiserfs_write_unlock_once(inode->i_sb, depth);
>  	} else {
>  		/* no object items are in the tree */
>  		;
>  	}
> -      out:
> -	reiserfs_write_unlock_once(inode->i_sb, depth);
>  	clear_inode(inode);	/* note this must go after the journal_end to prevent deadlock */
>  	dquot_drop(inode);
>  	inode->i_blocks = 0;
> @@ -1941,7 +1942,9 @@ int reiserfs_new_inode(struct reiserfs_t
>  	}
>  
>  	if (reiserfs_posixacl(inode->i_sb)) {
> +		reiserfs_write_unlock(inode->i_sb);
>  		retval = reiserfs_inherit_default_acl(th, dir, dentry, inode);
> +		reiserfs_write_lock(inode->i_sb);
>  		if (retval) {
>  			err = retval;
>  			reiserfs_check_path(&path_to_key);
> @@ -1956,7 +1959,9 @@ int reiserfs_new_inode(struct reiserfs_t
>  		inode->i_flags |= S_PRIVATE;
>  
>  	if (security->name) {
> +		reiserfs_write_unlock(inode->i_sb);
>  		retval = reiserfs_security_write(th, inode, security);
> +		reiserfs_write_lock(inode->i_sb);
>  		if (retval) {
>  			err = retval;
>  			reiserfs_check_path(&path_to_key);
> @@ -3129,6 +3134,7 @@ int reiserfs_setattr(struct dentry *dent
>  		 */
>  		if (get_inode_item_key_version(inode) == KEY_FORMAT_3_5 &&
>  		    attr->ia_size > MAX_NON_LFS) {
> +			reiserfs_write_unlock_once(inode->i_sb, depth);
>  			error = -EFBIG;
>  			goto out;
>  		}
> @@ -3150,8 +3156,10 @@ int reiserfs_setattr(struct dentry *dent
>  				if (err)
>  					error = err;
>  			}
> -			if (error)
> +			if (error) {
> +				reiserfs_write_unlock_once(inode->i_sb, depth);
>  				goto out;
> +			}
>  			/*
>  			 * file size is changed, ctime and mtime are
>  			 * to be updated
> @@ -3159,6 +3167,7 @@ int reiserfs_setattr(struct dentry *dent
>  			attr->ia_valid |= (ATTR_MTIME | ATTR_CTIME);
>  		}
>  	}
> +	reiserfs_write_unlock_once(inode->i_sb, depth);
>  
>  	if ((((attr->ia_valid & ATTR_UID) && (from_kuid(&init_user_ns, attr->ia_uid) & ~0xffff)) ||
>  	     ((attr->ia_valid & ATTR_GID) && (from_kgid(&init_user_ns, attr->ia_gid) & ~0xffff))) &&
> @@ -3183,14 +3192,16 @@ int reiserfs_setattr(struct dentry *dent
>  			return error;
>  
>  		/* (user+group)*(old+new) structure - we count quota info and , inode write (sb, inode) */
> +		depth = reiserfs_write_lock_once(inode->i_sb);
>  		error = journal_begin(&th, inode->i_sb, jbegin_count);
> +		reiserfs_write_unlock_once(inode->i_sb, depth);
>  		if (error)
>  			goto out;
> -		reiserfs_write_unlock_once(inode->i_sb, depth);
>  		error = dquot_transfer(inode, attr);
>  		depth = reiserfs_write_lock_once(inode->i_sb);
>  		if (error) {
>  			journal_end(&th, inode->i_sb, jbegin_count);
> +			reiserfs_write_unlock_once(inode->i_sb, depth);
>  			goto out;
>  		}
>  
> @@ -3202,17 +3213,11 @@ int reiserfs_setattr(struct dentry *dent
>  			inode->i_gid = attr->ia_gid;
>  		mark_inode_dirty(inode);
>  		error = journal_end(&th, inode->i_sb, jbegin_count);
> +		reiserfs_write_unlock_once(inode->i_sb, depth);
>  		if (error)
>  			goto out;
>  	}
>  
> -	/*
> -	 * Relax the lock here, as it might truncate the
> -	 * inode pages and wait for inode pages locks.
> -	 * To release such page lock, the owner needs the
> -	 * reiserfs lock
> -	 */
> -	reiserfs_write_unlock_once(inode->i_sb, depth);
>  	if ((attr->ia_valid & ATTR_SIZE) &&
>  	    attr->ia_size != i_size_read(inode)) {
>  		error = inode_newsize_ok(inode, attr->ia_size);
> @@ -3226,16 +3231,13 @@ int reiserfs_setattr(struct dentry *dent
>  		setattr_copy(inode, attr);
>  		mark_inode_dirty(inode);
>  	}
> -	depth = reiserfs_write_lock_once(inode->i_sb);
>  
>  	if (!error && reiserfs_posixacl(inode->i_sb)) {
>  		if (attr->ia_valid & ATTR_MODE)
>  			error = reiserfs_acl_chmod(inode);
>  	}
>  
> -      out:
> -	reiserfs_write_unlock_once(inode->i_sb, depth);
> -
> +out:
>  	return error;
>  }
>  
> --- a/fs/reiserfs/super.c	2013-08-07 10:23:30.681636170 -0400
> +++ b/fs/reiserfs/super.c	2013-08-07 10:23:31.637621664 -0400
> @@ -1335,7 +1335,7 @@ static int reiserfs_remount(struct super
>  				kfree(qf_names[i]);
>  #endif
>  		err = -EINVAL;
> -		goto out_unlock;
> +		goto out_err_unlock;
>  	}
>  #ifdef CONFIG_QUOTA
>  	handle_quota_files(s, qf_names, &qfmt);
> @@ -1379,35 +1379,32 @@ static int reiserfs_remount(struct super
>  	if (blocks) {
>  		err = reiserfs_resize(s, blocks);
>  		if (err != 0)
> -			goto out_unlock;
> +			goto out_err_unlock;
>  	}
>  
>  	if (*mount_flags & MS_RDONLY) {
> +		reiserfs_write_unlock(s);
>  		reiserfs_xattr_init(s, *mount_flags);
>  		/* remount read-only */
>  		if (s->s_flags & MS_RDONLY)
>  			/* it is read-only already */
> -			goto out_ok;
> +			goto out_ok_unlocked;
>  
> -		/*
> -		 * Drop write lock. Quota will retake it when needed and lock
> -		 * ordering requires calling dquot_suspend() without it.
> -		 */
> -		reiserfs_write_unlock(s);
>  		err = dquot_suspend(s, -1);
>  		if (err < 0)
>  			goto out_err;
> -		reiserfs_write_lock(s);
>  
>  		/* try to remount file system with read-only permissions */
>  		if (sb_umount_state(rs) == REISERFS_VALID_FS
>  		    || REISERFS_SB(s)->s_mount_state != REISERFS_VALID_FS) {
> -			goto out_ok;
> +			goto out_ok_unlocked;
>  		}
>  
> +		reiserfs_write_lock(s);
> +
>  		err = journal_begin(&th, s, 10);
>  		if (err)
> -			goto out_unlock;
> +			goto out_err_unlock;
>  
>  		/* Mounting a rw partition read-only. */
>  		reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
> @@ -1416,13 +1413,14 @@ static int reiserfs_remount(struct super
>  	} else {
>  		/* remount read-write */
>  		if (!(s->s_flags & MS_RDONLY)) {
> +			reiserfs_write_unlock(s);
>  			reiserfs_xattr_init(s, *mount_flags);
> -			goto out_ok;	/* We are read-write already */
> +			goto out_ok_unlocked;	/* We are read-write already */
>  		}
>  
>  		if (reiserfs_is_journal_aborted(journal)) {
>  			err = journal->j_errno;
> -			goto out_unlock;
> +			goto out_err_unlock;
>  		}
>  
>  		handle_data_mode(s, mount_options);
> @@ -1431,7 +1429,7 @@ static int reiserfs_remount(struct super
>  		s->s_flags &= ~MS_RDONLY;	/* now it is safe to call journal_begin */
>  		err = journal_begin(&th, s, 10);
>  		if (err)
> -			goto out_unlock;
> +			goto out_err_unlock;
>  
>  		/* Mount a partition which is read-only, read-write */
>  		reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
> @@ -1448,26 +1446,22 @@ static int reiserfs_remount(struct super
>  	SB_JOURNAL(s)->j_must_wait = 1;
>  	err = journal_end(&th, s, 10);
>  	if (err)
> -		goto out_unlock;
> +		goto out_err_unlock;
>  
> +	reiserfs_write_unlock(s);
>  	if (!(*mount_flags & MS_RDONLY)) {
> -		/*
> -		 * Drop write lock. Quota will retake it when needed and lock
> -		 * ordering requires calling dquot_resume() without it.
> -		 */
> -		reiserfs_write_unlock(s);
>  		dquot_resume(s, -1);
>  		reiserfs_write_lock(s);
>  		finish_unfinished(s);
> +		reiserfs_write_unlock(s);
>  		reiserfs_xattr_init(s, *mount_flags);
>  	}
>  
> -out_ok:
> +out_ok_unlocked:
>  	replace_mount_options(s, new_opts);
> -	reiserfs_write_unlock(s);
>  	return 0;
>  
> -out_unlock:
> +out_err_unlock:
>  	reiserfs_write_unlock(s);
>  out_err:
>  	kfree(new_opts);
> @@ -2014,12 +2008,14 @@ static int reiserfs_fill_super(struct su
>  			goto error;
>  		}
>  
> +		reiserfs_write_unlock(s);
>  		if ((errval = reiserfs_lookup_privroot(s)) ||
>  		    (errval = reiserfs_xattr_init(s, s->s_flags))) {
>  			dput(s->s_root);
>  			s->s_root = NULL;
> -			goto error;
> +			goto error_unlocked;
>  		}
> +		reiserfs_write_lock(s);
>  
>  		/* look for files which were to be removed in previous session */
>  		finish_unfinished(s);
> @@ -2028,12 +2024,14 @@ static int reiserfs_fill_super(struct su
>  			reiserfs_info(s, "using 3.5.x disk format\n");
>  		}
>  
> +		reiserfs_write_unlock(s);
>  		if ((errval = reiserfs_lookup_privroot(s)) ||
>  		    (errval = reiserfs_xattr_init(s, s->s_flags))) {
>  			dput(s->s_root);
>  			s->s_root = NULL;
> -			goto error;
> +			goto error_unlocked;
>  		}
> +		reiserfs_write_lock(s);
>  	}
>  	// mark hash in super block: it could be unset. overwrite should be ok
>  	set_sb_hash_function_code(rs, function2code(sbi->s_hash_function));
> --- a/fs/reiserfs/xattr.c	2013-08-07 10:23:30.681636170 -0400
> +++ b/fs/reiserfs/xattr.c	2013-08-07 10:23:31.649621482 -0400
> @@ -81,8 +81,7 @@ static int xattr_unlink(struct inode *di
>  	int error;
>  	BUG_ON(!mutex_is_locked(&dir->i_mutex));
>  
> -	reiserfs_mutex_lock_nested_safe(&dentry->d_inode->i_mutex,
> -					I_MUTEX_CHILD, dir->i_sb);
> +	mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
>  	error = dir->i_op->unlink(dir, dentry);
>  	mutex_unlock(&dentry->d_inode->i_mutex);
>  
> @@ -96,8 +95,7 @@ static int xattr_rmdir(struct inode *dir
>  	int error;
>  	BUG_ON(!mutex_is_locked(&dir->i_mutex));
>  
> -	reiserfs_mutex_lock_nested_safe(&dentry->d_inode->i_mutex,
> -					I_MUTEX_CHILD, dir->i_sb);
> +	mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
>  	error = dir->i_op->rmdir(dir, dentry);
>  	if (!error)
>  		dentry->d_inode->i_flags |= S_DEAD;
> @@ -232,22 +230,17 @@ static int reiserfs_for_each_xattr(struc
>  	if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
>  		return 0;
>  
> -	reiserfs_write_unlock(inode->i_sb);
>  	dir = open_xa_dir(inode, XATTR_REPLACE);
>  	if (IS_ERR(dir)) {
>  		err = PTR_ERR(dir);
> -		reiserfs_write_lock(inode->i_sb);
>  		goto out;
>  	} else if (!dir->d_inode) {
>  		err = 0;
> -		reiserfs_write_lock(inode->i_sb);
>  		goto out_dir;
>  	}
>  
>  	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
>  
> -	reiserfs_write_lock(inode->i_sb);
> -
>  	buf.xadir = dir;
>  	while (1) {
>  		err = reiserfs_readdir_inode(dir->d_inode, &buf.ctx);
> @@ -281,14 +274,17 @@ static int reiserfs_for_each_xattr(struc
>  		int blocks = JOURNAL_PER_BALANCE_CNT * 2 + 2 +
>  			     4 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb);
>  		struct reiserfs_transaction_handle th;
> +		reiserfs_write_lock(inode->i_sb);
>  		err = journal_begin(&th, inode->i_sb, blocks);
> +		reiserfs_write_unlock(inode->i_sb);
>  		if (!err) {
>  			int jerror;
> -			reiserfs_mutex_lock_nested_safe(
> -					  &dir->d_parent->d_inode->i_mutex,
> -					  I_MUTEX_XATTR, inode->i_sb);
> +			mutex_lock_nested(&dir->d_parent->d_inode->i_mutex,
> +					  I_MUTEX_XATTR);
>  			err = action(dir, data);
> +			reiserfs_write_lock(inode->i_sb);
>  			jerror = journal_end(&th, inode->i_sb, blocks);
> +			reiserfs_write_unlock(inode->i_sb);
>  			mutex_unlock(&dir->d_parent->d_inode->i_mutex);
>  			err = jerror ?: err;
>  		}
> @@ -455,9 +451,7 @@ static int lookup_and_delete_xattr(struc
>  	}
>  
>  	if (dentry->d_inode) {
> -		reiserfs_write_lock(inode->i_sb);
>  		err = xattr_unlink(xadir->d_inode, dentry);
> -		reiserfs_write_unlock(inode->i_sb);
>  		update_ctime(inode);
>  	}
>  
> @@ -491,24 +485,17 @@ reiserfs_xattr_set_handle(struct reiserf
>  	if (get_inode_sd_version(inode) == STAT_DATA_V1)
>  		return -EOPNOTSUPP;
>  
> -	reiserfs_write_unlock(inode->i_sb);
> -
>  	if (!buffer) {
>  		err = lookup_and_delete_xattr(inode, name);
> -		reiserfs_write_lock(inode->i_sb);
>  		return err;
>  	}
>  
>  	dentry = xattr_lookup(inode, name, flags);
> -	if (IS_ERR(dentry)) {
> -		reiserfs_write_lock(inode->i_sb);
> +	if (IS_ERR(dentry))
>  		return PTR_ERR(dentry);
> -	}
>  
>  	down_write(&REISERFS_I(inode)->i_xattr_sem);
>  
> -	reiserfs_write_lock(inode->i_sb);
> -
>  	xahash = xattr_hash(buffer, buffer_size);
>  	while (buffer_pos < buffer_size || buffer_pos == 0) {
>  		size_t chunk;
> @@ -538,6 +525,7 @@ reiserfs_xattr_set_handle(struct reiserf
>  			rxh->h_hash = cpu_to_le32(xahash);
>  		}
>  
> +		reiserfs_write_lock(inode->i_sb);
>  		err = __reiserfs_write_begin(page, page_offset, chunk + skip);
>  		if (!err) {
>  			if (buffer)
> @@ -546,6 +534,7 @@ reiserfs_xattr_set_handle(struct reiserf
>  						    page_offset + chunk +
>  						    skip);
>  		}
> +		reiserfs_write_unlock(inode->i_sb);
>  		unlock_page(page);
>  		reiserfs_put_page(page);
>  		buffer_pos += chunk;
> @@ -563,10 +552,8 @@ reiserfs_xattr_set_handle(struct reiserf
>  			.ia_valid = ATTR_SIZE | ATTR_CTIME,
>  		};
>  
> -		reiserfs_write_unlock(inode->i_sb);
>  		mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
>  		inode_dio_wait(dentry->d_inode);
> -		reiserfs_write_lock(inode->i_sb);
>  
>  		err = reiserfs_setattr(dentry, &newattrs);
>  		mutex_unlock(&dentry->d_inode->i_mutex);
> @@ -592,18 +579,19 @@ int reiserfs_xattr_set(struct inode *ino
>  
>  	reiserfs_write_lock(inode->i_sb);
>  	error = journal_begin(&th, inode->i_sb, jbegin_count);
> +	reiserfs_write_unlock(inode->i_sb);
>  	if (error) {
> -		reiserfs_write_unlock(inode->i_sb);
>  		return error;
>  	}
>  
>  	error = reiserfs_xattr_set_handle(&th, inode, name,
>  					  buffer, buffer_size, flags);
>  
> +	reiserfs_write_lock(inode->i_sb);
>  	error2 = journal_end(&th, inode->i_sb, jbegin_count);
> +	reiserfs_write_unlock(inode->i_sb);
>  	if (error == 0)
>  		error = error2;
> -	reiserfs_write_unlock(inode->i_sb);
>  
>  	return error;
>  }
> @@ -968,7 +956,7 @@ int reiserfs_lookup_privroot(struct supe
>  	int err = 0;
>  
>  	/* If we don't have the privroot located yet - go find it */
> -	reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
> +	mutex_lock(&s->s_root->d_inode->i_mutex);
>  	dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
>  				strlen(PRIVROOT_NAME));
>  	if (!IS_ERR(dentry)) {
> @@ -996,14 +984,14 @@ int reiserfs_xattr_init(struct super_blo
>  		goto error;
>  
>  	if (!privroot->d_inode && !(mount_flags & MS_RDONLY)) {
> -		reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
> +		mutex_lock(&s->s_root->d_inode->i_mutex);
>  		err = create_privroot(REISERFS_SB(s)->priv_root);
>  		mutex_unlock(&s->s_root->d_inode->i_mutex);
>  	}
>  
>  	if (privroot->d_inode) {
>  		s->s_xattr = reiserfs_xattr_handlers;
> -		reiserfs_mutex_lock_safe(&privroot->d_inode->i_mutex, s);
> +		mutex_lock(&privroot->d_inode->i_mutex);
>  		if (!REISERFS_SB(s)->xattr_root) {
>  			struct dentry *dentry;
>  			dentry = lookup_one_len(XAROOT_NAME, privroot,
> --- a/fs/reiserfs/xattr_acl.c	2013-08-07 10:23:30.681636170 -0400
> +++ b/fs/reiserfs/xattr_acl.c	2013-08-07 10:23:31.661621300 -0400
> @@ -49,13 +49,15 @@ posix_acl_set(struct dentry *dentry, con
>  
>  	reiserfs_write_lock(inode->i_sb);
>  	error = journal_begin(&th, inode->i_sb, jcreate_blocks);
> +	reiserfs_write_unlock(inode->i_sb);
>  	if (error == 0) {
>  		error = reiserfs_set_acl(&th, inode, type, acl);
> +		reiserfs_write_lock(inode->i_sb);
>  		error2 = journal_end(&th, inode->i_sb, jcreate_blocks);
> +		reiserfs_write_unlock(inode->i_sb);
>  		if (error2)
>  			error = error2;
>  	}
> -	reiserfs_write_unlock(inode->i_sb);
>  
>        release_and_out:
>  	posix_acl_release(acl);
> @@ -435,12 +437,14 @@ int reiserfs_cache_default_acl(struct in
>  	return nblocks;
>  }
>  
> +/*
> + * Called under i_mutex
> + */
>  int reiserfs_acl_chmod(struct inode *inode)
>  {
>  	struct reiserfs_transaction_handle th;
>  	struct posix_acl *acl;
>  	size_t size;
> -	int depth;
>  	int error;
>  
>  	if (IS_PRIVATE(inode))
> @@ -454,9 +458,7 @@ int reiserfs_acl_chmod(struct inode *ino
>  		return 0;
>  	}
>  
> -	reiserfs_write_unlock(inode->i_sb);
>  	acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
> -	reiserfs_write_lock(inode->i_sb);
>  	if (!acl)
>  		return 0;
>  	if (IS_ERR(acl))
> @@ -466,16 +468,18 @@ int reiserfs_acl_chmod(struct inode *ino
>  		return error;
>  
>  	size = reiserfs_xattr_nblocks(inode, reiserfs_acl_size(acl->a_count));
> -	depth = reiserfs_write_lock_once(inode->i_sb);
> +	reiserfs_write_lock(inode->i_sb);
>  	error = journal_begin(&th, inode->i_sb, size * 2);
> +	reiserfs_write_unlock(inode->i_sb);
>  	if (!error) {
>  		int error2;
>  		error = reiserfs_set_acl(&th, inode, ACL_TYPE_ACCESS, acl);
> +		reiserfs_write_lock(inode->i_sb);
>  		error2 = journal_end(&th, inode->i_sb, size * 2);
> +		reiserfs_write_unlock(inode->i_sb);
>  		if (error2)
>  			error = error2;
>  	}
> -	reiserfs_write_unlock_once(inode->i_sb, depth);
>  	posix_acl_release(acl);
>  	return error;
>  }
> 
> 
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR

[patch v3 2/3] reiserfs: locking, handle nested locks properly

[Jeff Mahoney]

[-- Attachment #1: reiserfs/reiserfs-locking-handle-nested-locks-properly --]
[-- Type: text/plain, Size: 39933 bytes --]

The reiserfs write lock replaced the BKL and uses similar semantics.

Frederic's locking code makes a distinction between when the lock is nested
and when it's being acquired/released, but I don't think that's the right
distinction to make.

The right distinction is between the lock being released at end-of-use and
the lock being released for a schedule. The unlock should return the depth
and the lock should restore it, rather than the other way around as it is now.

This patch implements that and adds a number of places where the lock
should be dropped.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
---

 fs/reiserfs/bitmap.c   |    5 +-
 fs/reiserfs/dir.c      |    7 +--
 fs/reiserfs/fix_node.c |   26 ++++++------
 fs/reiserfs/inode.c    |   77 ++++++++++++++++--------------------
 fs/reiserfs/ioctl.c    |    7 +--
 fs/reiserfs/journal.c  |  104 ++++++++++++++++++++++++++-----------------------
 fs/reiserfs/lock.c     |   43 ++++++++++----------
 fs/reiserfs/namei.c    |   24 +++--------
 fs/reiserfs/prints.c   |    5 +-
 fs/reiserfs/reiserfs.h |   36 +++++++++-------
 fs/reiserfs/resize.c   |   10 +++-
 fs/reiserfs/stree.c    |   16 +++----
 fs/reiserfs/super.c    |    5 --
 13 files changed, 188 insertions(+), 177 deletions(-)

--- a/fs/reiserfs/bitmap.c	2013-08-07 10:23:30.201643452 -0400
+++ b/fs/reiserfs/bitmap.c	2013-08-07 10:23:33.885587547 -0400
@@ -1340,10 +1340,11 @@ struct buffer_head *reiserfs_read_bitmap
 		                 "reading failed", __func__, block);
 	else {
 		if (buffer_locked(bh)) {
+			int depth;
 			PROC_INFO_INC(sb, scan_bitmap.wait);
-			reiserfs_write_unlock(sb);
+			depth = reiserfs_write_unlock_nested(sb);
 			__wait_on_buffer(bh);
-			reiserfs_write_lock(sb);
+			reiserfs_write_lock_nested(sb, depth);
 		}
 		BUG_ON(!buffer_uptodate(bh));
 		BUG_ON(atomic_read(&bh->b_count) == 0);
--- a/fs/reiserfs/dir.c	2013-08-07 10:23:30.201643452 -0400
+++ b/fs/reiserfs/dir.c	2013-08-07 10:23:33.905587250 -0400
@@ -71,6 +71,7 @@ int reiserfs_readdir_inode(struct inode
 	char small_buf[32];	/* avoid kmalloc if we can */
 	struct reiserfs_dir_entry de;
 	int ret = 0;
+	int depth;
 
 	reiserfs_write_lock(inode->i_sb);
 
@@ -181,17 +182,17 @@ int reiserfs_readdir_inode(struct inode
 				 * Since filldir might sleep, we can release
 				 * the write lock here for other waiters
 				 */
-				reiserfs_write_unlock(inode->i_sb);
+				depth = reiserfs_write_unlock_nested(inode->i_sb);
 				if (!dir_emit
 				    (ctx, local_buf, d_reclen, d_ino,
 				     DT_UNKNOWN)) {
-					reiserfs_write_lock(inode->i_sb);
+					reiserfs_write_lock_nested(inode->i_sb, depth);
 					if (local_buf != small_buf) {
 						kfree(local_buf);
 					}
 					goto end;
 				}
-				reiserfs_write_lock(inode->i_sb);
+				reiserfs_write_lock_nested(inode->i_sb, depth);
 				if (local_buf != small_buf) {
 					kfree(local_buf);
 				}
--- a/fs/reiserfs/fix_node.c	2013-08-07 10:23:30.201643452 -0400
+++ b/fs/reiserfs/fix_node.c	2013-08-07 10:23:33.917587068 -0400
@@ -1022,9 +1022,9 @@ static int get_far_parent(struct tree_ba
 	if (buffer_locked(*pcom_father)) {
 
 		/* Release the write lock while the buffer is busy */
-		reiserfs_write_unlock(tb->tb_sb);
+		int depth = reiserfs_write_unlock_nested(tb->tb_sb);
 		__wait_on_buffer(*pcom_father);
-		reiserfs_write_lock(tb->tb_sb);
+		reiserfs_write_lock_nested(tb->tb_sb, depth);
 		if (FILESYSTEM_CHANGED_TB(tb)) {
 			brelse(*pcom_father);
 			return REPEAT_SEARCH;
@@ -1929,9 +1929,9 @@ static int get_direct_parent(struct tree
 		return REPEAT_SEARCH;
 
 	if (buffer_locked(bh)) {
-		reiserfs_write_unlock(tb->tb_sb);
+		int depth = reiserfs_write_unlock_nested(tb->tb_sb);
 		__wait_on_buffer(bh);
-		reiserfs_write_lock(tb->tb_sb);
+		reiserfs_write_lock_nested(tb->tb_sb, depth);
 		if (FILESYSTEM_CHANGED_TB(tb))
 			return REPEAT_SEARCH;
 	}
@@ -1952,6 +1952,7 @@ static int get_neighbors(struct tree_bal
 	unsigned long son_number;
 	struct super_block *sb = tb->tb_sb;
 	struct buffer_head *bh;
+	int depth;
 
 	PROC_INFO_INC(sb, get_neighbors[h]);
 
@@ -1969,9 +1970,9 @@ static int get_neighbors(struct tree_bal
 		     tb->FL[h]) ? tb->lkey[h] : B_NR_ITEMS(tb->
 								       FL[h]);
 		son_number = B_N_CHILD_NUM(tb->FL[h], child_position);
-		reiserfs_write_unlock(sb);
+		depth = reiserfs_write_unlock_nested(tb->tb_sb);
 		bh = sb_bread(sb, son_number);
-		reiserfs_write_lock(sb);
+		reiserfs_write_lock_nested(tb->tb_sb, depth);
 		if (!bh)
 			return IO_ERROR;
 		if (FILESYSTEM_CHANGED_TB(tb)) {
@@ -2009,9 +2010,9 @@ static int get_neighbors(struct tree_bal
 		child_position =
 		    (bh == tb->FR[h]) ? tb->rkey[h] + 1 : 0;
 		son_number = B_N_CHILD_NUM(tb->FR[h], child_position);
-		reiserfs_write_unlock(sb);
+		depth = reiserfs_write_unlock_nested(tb->tb_sb);
 		bh = sb_bread(sb, son_number);
-		reiserfs_write_lock(sb);
+		reiserfs_write_lock_nested(tb->tb_sb, depth);
 		if (!bh)
 			return IO_ERROR;
 		if (FILESYSTEM_CHANGED_TB(tb)) {
@@ -2272,6 +2273,7 @@ static int wait_tb_buffers_until_unlocke
 		}
 
 		if (locked) {
+			int depth;
 #ifdef CONFIG_REISERFS_CHECK
 			repeat_counter++;
 			if ((repeat_counter % 10000) == 0) {
@@ -2286,9 +2288,9 @@ static int wait_tb_buffers_until_unlocke
 				    REPEAT_SEARCH : CARRY_ON;
 			}
 #endif
-			reiserfs_write_unlock(tb->tb_sb);
+			depth = reiserfs_write_unlock_nested(tb->tb_sb);
 			__wait_on_buffer(locked);
-			reiserfs_write_lock(tb->tb_sb);
+			reiserfs_write_lock_nested(tb->tb_sb, depth);
 			if (FILESYSTEM_CHANGED_TB(tb))
 				return REPEAT_SEARCH;
 		}
@@ -2359,9 +2361,9 @@ int fix_nodes(int op_mode, struct tree_b
 
 	/* if it possible in indirect_to_direct conversion */
 	if (buffer_locked(tbS0)) {
-		reiserfs_write_unlock(tb->tb_sb);
+		int depth = reiserfs_write_unlock_nested(tb->tb_sb);
 		__wait_on_buffer(tbS0);
-		reiserfs_write_lock(tb->tb_sb);
+		reiserfs_write_lock_nested(tb->tb_sb, depth);
 		if (FILESYSTEM_CHANGED_TB(tb))
 			return REPEAT_SEARCH;
 	}
--- a/fs/reiserfs/inode.c	2013-08-07 10:23:31.613622029 -0400
+++ b/fs/reiserfs/inode.c	2013-08-07 10:23:33.933586826 -0400
@@ -41,11 +41,10 @@ void reiserfs_evict_inode(struct inode *
 
 	/* The = 0 happens when we abort creating a new inode for some reason like lack of space.. */
 	if (!(inode->i_state & I_NEW) && INODE_PKEY(inode)->k_objectid != 0) {	/* also handles bad_inode case */
-		int depth;
 
 		reiserfs_delete_xattrs(inode);
 
-		depth = reiserfs_write_lock_once(inode->i_sb);
+		reiserfs_write_lock(inode->i_sb);
 
 		if (journal_begin(&th, inode->i_sb, jbegin_count))
 			goto out;
@@ -74,7 +73,7 @@ void reiserfs_evict_inode(struct inode *
 		remove_save_link(inode, 0 /* not truncate */ );	/* we can't do anything
 								 * about an error here */
 out:
-		reiserfs_write_unlock_once(inode->i_sb, depth);
+		reiserfs_write_unlock(inode->i_sb);
 	} else {
 		/* no object items are in the tree */
 		;
@@ -611,7 +610,6 @@ int reiserfs_get_block(struct inode *ino
 	__le32 *item;
 	int done;
 	int fs_gen;
-	int lock_depth;
 	struct reiserfs_transaction_handle *th = NULL;
 	/* space reserved in transaction batch:
 	   . 3 balancings in direct->indirect conversion
@@ -627,11 +625,11 @@ int reiserfs_get_block(struct inode *ino
 	loff_t new_offset =
 	    (((loff_t) block) << inode->i_sb->s_blocksize_bits) + 1;
 
-	lock_depth = reiserfs_write_lock_once(inode->i_sb);
+	reiserfs_write_lock(inode->i_sb);
 	version = get_inode_item_key_version(inode);
 
 	if (!file_capable(inode, block)) {
-		reiserfs_write_unlock_once(inode->i_sb, lock_depth);
+		reiserfs_write_unlock(inode->i_sb);
 		return -EFBIG;
 	}
 
@@ -643,7 +641,7 @@ int reiserfs_get_block(struct inode *ino
 		/* find number of block-th logical block of the file */
 		ret = _get_block_create_0(inode, block, bh_result,
 					  create | GET_BLOCK_READ_DIRECT);
-		reiserfs_write_unlock_once(inode->i_sb, lock_depth);
+		reiserfs_write_unlock(inode->i_sb);
 		return ret;
 	}
 	/*
@@ -761,7 +759,7 @@ int reiserfs_get_block(struct inode *ino
 		if (!dangle && th)
 			retval = reiserfs_end_persistent_transaction(th);
 
-		reiserfs_write_unlock_once(inode->i_sb, lock_depth);
+		reiserfs_write_unlock(inode->i_sb);
 
 		/* the item was found, so new blocks were not added to the file
 		 ** there is no need to make sure the inode is updated with this
@@ -1012,11 +1010,7 @@ int reiserfs_get_block(struct inode *ino
 		 * long time.  reschedule if needed and also release the write
 		 * lock for others.
 		 */
-		if (need_resched()) {
-			reiserfs_write_unlock_once(inode->i_sb, lock_depth);
-			schedule();
-			lock_depth = reiserfs_write_lock_once(inode->i_sb);
-		}
+		reiserfs_cond_resched(inode->i_sb);
 
 		retval = search_for_position_by_key(inode->i_sb, &key, &path);
 		if (retval == IO_ERROR) {
@@ -1051,7 +1045,7 @@ int reiserfs_get_block(struct inode *ino
 			retval = err;
 	}
 
-	reiserfs_write_unlock_once(inode->i_sb, lock_depth);
+	reiserfs_write_unlock(inode->i_sb);
 	reiserfs_check_path(&path);
 	return retval;
 }
@@ -1510,14 +1504,15 @@ struct inode *reiserfs_iget(struct super
 {
 	struct inode *inode;
 	struct reiserfs_iget_args args;
+	int depth;
 
 	args.objectid = key->on_disk_key.k_objectid;
 	args.dirid = key->on_disk_key.k_dir_id;
-	reiserfs_write_unlock(s);
+	depth = reiserfs_write_unlock_nested(s);
 	inode = iget5_locked(s, key->on_disk_key.k_objectid,
 			     reiserfs_find_actor, reiserfs_init_locked_inode,
 			     (void *)(&args));
-	reiserfs_write_lock(s);
+	reiserfs_write_lock_nested(s, depth);
 	if (!inode)
 		return ERR_PTR(-ENOMEM);
 
@@ -1781,6 +1776,7 @@ int reiserfs_new_inode(struct reiserfs_t
 	struct stat_data sd;
 	int retval;
 	int err;
+	int depth;
 
 	BUG_ON(!th->t_trans_id);
 
@@ -1813,10 +1809,10 @@ int reiserfs_new_inode(struct reiserfs_t
 	memcpy(INODE_PKEY(inode), &(ih.ih_key), KEY_SIZE);
 	args.dirid = le32_to_cpu(ih.ih_key.k_dir_id);
 
-	reiserfs_write_unlock(inode->i_sb);
+	depth = reiserfs_write_unlock_nested(inode->i_sb);
 	err = insert_inode_locked4(inode, args.objectid,
 			     reiserfs_find_actor, &args);
-	reiserfs_write_lock(inode->i_sb);
+	reiserfs_write_lock_nested(inode->i_sb, depth);
 	if (err) {
 		err = -EINVAL;
 		goto out_bad_inode;
@@ -2108,9 +2104,8 @@ int reiserfs_truncate_file(struct inode
 	int error;
 	struct buffer_head *bh = NULL;
 	int err2;
-	int lock_depth;
 
-	lock_depth = reiserfs_write_lock_once(inode->i_sb);
+	reiserfs_write_lock(inode->i_sb);
 
 	if (inode->i_size > 0) {
 		error = grab_tail_page(inode, &page, &bh);
@@ -2179,7 +2174,7 @@ int reiserfs_truncate_file(struct inode
 		page_cache_release(page);
 	}
 
-	reiserfs_write_unlock_once(inode->i_sb, lock_depth);
+	reiserfs_write_unlock(inode->i_sb);
 
 	return 0;
       out:
@@ -2188,7 +2183,7 @@ int reiserfs_truncate_file(struct inode
 		page_cache_release(page);
 	}
 
-	reiserfs_write_unlock_once(inode->i_sb, lock_depth);
+	reiserfs_write_unlock(inode->i_sb);
 
 	return error;
 }
@@ -2653,10 +2648,11 @@ int __reiserfs_write_begin(struct page *
 	struct inode *inode = page->mapping->host;
 	int ret;
 	int old_ref = 0;
+	int depth;
 
-	reiserfs_write_unlock(inode->i_sb);
+	depth = reiserfs_write_unlock_nested(inode->i_sb);
 	reiserfs_wait_on_write_block(inode->i_sb);
-	reiserfs_write_lock(inode->i_sb);
+	reiserfs_write_lock_nested(inode->i_sb, depth);
 
 	fix_tail_page_for_writing(page);
 	if (reiserfs_transaction_running(inode->i_sb)) {
@@ -2713,7 +2709,6 @@ static int reiserfs_write_end(struct fil
 	int update_sd = 0;
 	struct reiserfs_transaction_handle *th;
 	unsigned start;
-	int lock_depth = 0;
 	bool locked = false;
 
 	if ((unsigned long)fsdata & AOP_FLAG_CONT_EXPAND)
@@ -2742,7 +2737,7 @@ static int reiserfs_write_end(struct fil
 	 */
 	if (pos + copied > inode->i_size) {
 		struct reiserfs_transaction_handle myth;
-		lock_depth = reiserfs_write_lock_once(inode->i_sb);
+		reiserfs_write_lock(inode->i_sb);
 		locked = true;
 		/* If the file have grown beyond the border where it
 		   can have a tail, unmark it as needing a tail
@@ -2773,7 +2768,7 @@ static int reiserfs_write_end(struct fil
 	}
 	if (th) {
 		if (!locked) {
-			lock_depth = reiserfs_write_lock_once(inode->i_sb);
+			reiserfs_write_lock(inode->i_sb);
 			locked = true;
 		}
 		if (!update_sd)
@@ -2785,7 +2780,7 @@ static int reiserfs_write_end(struct fil
 
       out:
 	if (locked)
-		reiserfs_write_unlock_once(inode->i_sb, lock_depth);
+		reiserfs_write_unlock(inode->i_sb);
 	unlock_page(page);
 	page_cache_release(page);
 
@@ -2795,7 +2790,7 @@ static int reiserfs_write_end(struct fil
 	return ret == 0 ? copied : ret;
 
       journal_error:
-	reiserfs_write_unlock_once(inode->i_sb, lock_depth);
+	reiserfs_write_unlock(inode->i_sb);
 	locked = false;
 	if (th) {
 		if (!update_sd)
@@ -2813,10 +2808,11 @@ int reiserfs_commit_write(struct file *f
 	int ret = 0;
 	int update_sd = 0;
 	struct reiserfs_transaction_handle *th = NULL;
+	int depth;
 
-	reiserfs_write_unlock(inode->i_sb);
+	depth = reiserfs_write_unlock_nested(inode->i_sb);
 	reiserfs_wait_on_write_block(inode->i_sb);
-	reiserfs_write_lock(inode->i_sb);
+	reiserfs_write_lock_nested(inode->i_sb, depth);
 
 	if (reiserfs_transaction_running(inode->i_sb)) {
 		th = current->journal_info;
@@ -3115,7 +3111,6 @@ int reiserfs_setattr(struct dentry *dent
 {
 	struct inode *inode = dentry->d_inode;
 	unsigned int ia_valid;
-	int depth;
 	int error;
 
 	error = inode_change_ok(inode, attr);
@@ -3127,14 +3122,14 @@ int reiserfs_setattr(struct dentry *dent
 
 	if (is_quota_modification(inode, attr))
 		dquot_initialize(inode);
-	depth = reiserfs_write_lock_once(inode->i_sb);
+	reiserfs_write_lock(inode->i_sb);
 	if (attr->ia_valid & ATTR_SIZE) {
 		/* version 2 items will be caught by the s_maxbytes check
 		 ** done for us in vmtruncate
 		 */
 		if (get_inode_item_key_version(inode) == KEY_FORMAT_3_5 &&
 		    attr->ia_size > MAX_NON_LFS) {
-			reiserfs_write_unlock_once(inode->i_sb, depth);
+			reiserfs_write_unlock(inode->i_sb);
 			error = -EFBIG;
 			goto out;
 		}
@@ -3157,7 +3152,7 @@ int reiserfs_setattr(struct dentry *dent
 					error = err;
 			}
 			if (error) {
-				reiserfs_write_unlock_once(inode->i_sb, depth);
+				reiserfs_write_unlock(inode->i_sb);
 				goto out;
 			}
 			/*
@@ -3167,7 +3162,7 @@ int reiserfs_setattr(struct dentry *dent
 			attr->ia_valid |= (ATTR_MTIME | ATTR_CTIME);
 		}
 	}
-	reiserfs_write_unlock_once(inode->i_sb, depth);
+	reiserfs_write_unlock(inode->i_sb);
 
 	if ((((attr->ia_valid & ATTR_UID) && (from_kuid(&init_user_ns, attr->ia_uid) & ~0xffff)) ||
 	     ((attr->ia_valid & ATTR_GID) && (from_kgid(&init_user_ns, attr->ia_gid) & ~0xffff))) &&
@@ -3192,16 +3187,16 @@ int reiserfs_setattr(struct dentry *dent
 			return error;
 
 		/* (user+group)*(old+new) structure - we count quota info and , inode write (sb, inode) */
-		depth = reiserfs_write_lock_once(inode->i_sb);
+		reiserfs_write_lock(inode->i_sb);
 		error = journal_begin(&th, inode->i_sb, jbegin_count);
-		reiserfs_write_unlock_once(inode->i_sb, depth);
+		reiserfs_write_unlock(inode->i_sb);
 		if (error)
 			goto out;
 		error = dquot_transfer(inode, attr);
-		depth = reiserfs_write_lock_once(inode->i_sb);
+		reiserfs_write_lock(inode->i_sb);
 		if (error) {
 			journal_end(&th, inode->i_sb, jbegin_count);
-			reiserfs_write_unlock_once(inode->i_sb, depth);
+			reiserfs_write_unlock(inode->i_sb);
 			goto out;
 		}
 
@@ -3213,7 +3208,7 @@ int reiserfs_setattr(struct dentry *dent
 			inode->i_gid = attr->ia_gid;
 		mark_inode_dirty(inode);
 		error = journal_end(&th, inode->i_sb, jbegin_count);
-		reiserfs_write_unlock_once(inode->i_sb, depth);
+		reiserfs_write_unlock(inode->i_sb);
 		if (error)
 			goto out;
 	}
--- a/fs/reiserfs/ioctl.c	2013-08-07 10:23:30.201643452 -0400
+++ b/fs/reiserfs/ioctl.c	2013-08-07 10:23:33.941586702 -0400
@@ -167,7 +167,6 @@ int reiserfs_commit_write(struct file *f
 int reiserfs_unpack(struct inode *inode, struct file *filp)
 {
 	int retval = 0;
-	int depth;
 	int index;
 	struct page *page;
 	struct address_space *mapping;
@@ -183,11 +182,11 @@ int reiserfs_unpack(struct inode *inode,
 		return 0;
 	}
 
-	depth = reiserfs_write_lock_once(inode->i_sb);
-
 	/* we need to make sure nobody is changing the file size beneath us */
 	reiserfs_mutex_lock_safe(&inode->i_mutex, inode->i_sb);
 
+	reiserfs_write_lock(inode->i_sb);
+
 	write_from = inode->i_size & (blocksize - 1);
 	/* if we are on a block boundary, we are already unpacked.  */
 	if (write_from == 0) {
@@ -221,6 +220,6 @@ int reiserfs_unpack(struct inode *inode,
 
       out:
 	mutex_unlock(&inode->i_mutex);
-	reiserfs_write_unlock_once(inode->i_sb, depth);
+	reiserfs_write_unlock(inode->i_sb);
 	return retval;
 }
--- a/fs/reiserfs/journal.c	2013-08-07 10:23:30.205643392 -0400
+++ b/fs/reiserfs/journal.c	2013-08-07 10:23:33.957586463 -0400
@@ -947,9 +947,11 @@ static int reiserfs_async_progress_wait(
 	struct reiserfs_journal *j = SB_JOURNAL(s);
 
 	if (atomic_read(&j->j_async_throttle)) {
-		reiserfs_write_unlock(s);
+		int depth;
+
+		depth = reiserfs_write_unlock_nested(s);
 		congestion_wait(BLK_RW_ASYNC, HZ / 10);
-		reiserfs_write_lock(s);
+		reiserfs_write_lock_nested(s, depth);
 	}
 
 	return 0;
@@ -972,6 +974,7 @@ static int flush_commit_list(struct supe
 	struct reiserfs_journal *journal = SB_JOURNAL(s);
 	int retval = 0;
 	int write_len;
+	int depth;
 
 	reiserfs_check_lock_depth(s, "flush_commit_list");
 
@@ -1018,12 +1021,12 @@ static int flush_commit_list(struct supe
 		 * We might sleep in numerous places inside
 		 * write_ordered_buffers. Relax the write lock.
 		 */
-		reiserfs_write_unlock(s);
+		depth = reiserfs_write_unlock_nested(s);
 		ret = write_ordered_buffers(&journal->j_dirty_buffers_lock,
 					    journal, jl, &jl->j_bh_list);
 		if (ret < 0 && retval == 0)
 			retval = ret;
-		reiserfs_write_lock(s);
+		reiserfs_write_lock_nested(s, depth);
 	}
 	BUG_ON(!list_empty(&jl->j_bh_list));
 	/*
@@ -1043,9 +1046,9 @@ static int flush_commit_list(struct supe
 		tbh = journal_find_get_block(s, bn);
 		if (tbh) {
 			if (buffer_dirty(tbh)) {
-		            reiserfs_write_unlock(s);
+		            depth = reiserfs_write_unlock_nested(s);
 			    ll_rw_block(WRITE, 1, &tbh);
-			    reiserfs_write_lock(s);
+			    reiserfs_write_lock_nested(s, depth);
 			}
 			put_bh(tbh) ;
 		}
@@ -1057,17 +1060,17 @@ static int flush_commit_list(struct supe
 		    (jl->j_start + i) % SB_ONDISK_JOURNAL_SIZE(s);
 		tbh = journal_find_get_block(s, bn);
 
-		reiserfs_write_unlock(s);
-		wait_on_buffer(tbh);
-		reiserfs_write_lock(s);
+		depth = reiserfs_write_unlock_nested(s);
+		__wait_on_buffer(tbh);
+		reiserfs_write_lock_nested(s, depth);
 		// since we're using ll_rw_blk above, it might have skipped over
 		// a locked buffer.  Double check here
 		//
 		/* redundant, sync_dirty_buffer() checks */
 		if (buffer_dirty(tbh)) {
-			reiserfs_write_unlock(s);
+			depth = reiserfs_write_unlock_nested(s);
 			sync_dirty_buffer(tbh);
-			reiserfs_write_lock(s);
+			reiserfs_write_lock_nested(s, depth);
 		}
 		if (unlikely(!buffer_uptodate(tbh))) {
 #ifdef CONFIG_REISERFS_CHECK
@@ -1091,12 +1094,12 @@ static int flush_commit_list(struct supe
 		if (buffer_dirty(jl->j_commit_bh))
 			BUG();
 		mark_buffer_dirty(jl->j_commit_bh) ;
-		reiserfs_write_unlock(s);
+		depth = reiserfs_write_unlock_nested(s);
 		if (reiserfs_barrier_flush(s))
 			__sync_dirty_buffer(jl->j_commit_bh, WRITE_FLUSH_FUA);
 		else
 			sync_dirty_buffer(jl->j_commit_bh);
-		reiserfs_write_lock(s);
+		reiserfs_write_lock_nested(s, depth);
 	}
 
 	/* If there was a write error in the journal - we can't commit this
@@ -1228,15 +1231,16 @@ static int _update_journal_header_block(
 {
 	struct reiserfs_journal_header *jh;
 	struct reiserfs_journal *journal = SB_JOURNAL(sb);
+	int depth;
 
 	if (reiserfs_is_journal_aborted(journal))
 		return -EIO;
 
 	if (trans_id >= journal->j_last_flush_trans_id) {
 		if (buffer_locked((journal->j_header_bh))) {
-			reiserfs_write_unlock(sb);
-			wait_on_buffer((journal->j_header_bh));
-			reiserfs_write_lock(sb);
+			depth = reiserfs_write_unlock_nested(sb);
+			__wait_on_buffer(journal->j_header_bh);
+			reiserfs_write_lock_nested(sb, depth);
 			if (unlikely(!buffer_uptodate(journal->j_header_bh))) {
 #ifdef CONFIG_REISERFS_CHECK
 				reiserfs_warning(sb, "journal-699",
@@ -1254,14 +1258,14 @@ static int _update_journal_header_block(
 		jh->j_mount_id = cpu_to_le32(journal->j_mount_id);
 
 		set_buffer_dirty(journal->j_header_bh);
-		reiserfs_write_unlock(sb);
+		depth = reiserfs_write_unlock_nested(sb);
 
 		if (reiserfs_barrier_flush(sb))
 			__sync_dirty_buffer(journal->j_header_bh, WRITE_FLUSH_FUA);
 		else
 			sync_dirty_buffer(journal->j_header_bh);
 
-		reiserfs_write_lock(sb);
+		reiserfs_write_lock_nested(sb, depth);
 		if (!buffer_uptodate(journal->j_header_bh)) {
 			reiserfs_warning(sb, "journal-837",
 					 "IO error during journal replay");
@@ -1341,6 +1345,7 @@ static int flush_journal_list(struct sup
 	unsigned long j_len_saved = jl->j_len;
 	struct reiserfs_journal *journal = SB_JOURNAL(s);
 	int err = 0;
+	int depth;
 
 	BUG_ON(j_len_saved <= 0);
 
@@ -1495,9 +1500,9 @@ static int flush_journal_list(struct sup
 						       "cn->bh is NULL");
 				}
 
-				reiserfs_write_unlock(s);
-				wait_on_buffer(cn->bh);
-				reiserfs_write_lock(s);
+				depth = reiserfs_write_unlock_nested(s);
+				__wait_on_buffer(cn->bh);
+				reiserfs_write_lock_nested(s, depth);
 
 				if (!cn->bh) {
 					reiserfs_panic(s, "journal-1012",
@@ -1974,6 +1979,7 @@ static int journal_compare_desc_commit(s
 /* returns 0 if it did not find a description block
 ** returns -1 if it found a corrupt commit block
 ** returns 1 if both desc and commit were valid
+** NOTE: only called during fs mount
 */
 static int journal_transaction_is_valid(struct super_block *sb,
 					struct buffer_head *d_bh,
@@ -2073,8 +2079,9 @@ static void brelse_array(struct buffer_h
 
 /*
 ** given the start, and values for the oldest acceptable transactions,
-** this either reads in a replays a transaction, or returns because the transaction
-** is invalid, or too old.
+** this either reads in a replays a transaction, or returns because the
+** transaction is invalid, or too old.
+** NOTE: only called during fs mount
 */
 static int journal_read_transaction(struct super_block *sb,
 				    unsigned long cur_dblock,
@@ -2208,10 +2215,7 @@ static int journal_read_transaction(stru
 	ll_rw_block(READ, get_desc_trans_len(desc), log_blocks);
 	for (i = 0; i < get_desc_trans_len(desc); i++) {
 
-		reiserfs_write_unlock(sb);
 		wait_on_buffer(log_blocks[i]);
-		reiserfs_write_lock(sb);
-
 		if (!buffer_uptodate(log_blocks[i])) {
 			reiserfs_warning(sb, "journal-1212",
 					 "REPLAY FAILURE fsck required! "
@@ -2318,12 +2322,13 @@ static struct buffer_head *reiserfs_brea
 
 /*
 ** read and replay the log
-** on a clean unmount, the journal header's next unflushed pointer will be to an invalid
-** transaction.  This tests that before finding all the transactions in the log, which makes normal mount times fast.
-**
-** After a crash, this starts with the next unflushed transaction, and replays until it finds one too old, or invalid.
-**
+** on a clean unmount, the journal header's next unflushed pointer will
+** be to an invalid transaction.  This tests that before finding all the
+** transactions in the log, which makes normal mount times fast.
+** After a crash, this starts with the next unflushed transaction, and
+** replays until it finds one too old, or invalid.
 ** On exit, it sets things up so the first transaction will work correctly.
+** NOTE: only called during fs mount
 */
 static int journal_read(struct super_block *sb)
 {
@@ -2501,14 +2506,18 @@ static int journal_read(struct super_blo
 			      "replayed %d transactions in %lu seconds\n",
 			      replay_count, get_seconds() - start);
 	}
+	/* needed to satisfy the locking in _update_journal_header_block */
+	reiserfs_write_lock(sb);
 	if (!bdev_read_only(sb->s_bdev) &&
 	    _update_journal_header_block(sb, journal->j_start,
 					 journal->j_last_flush_trans_id)) {
+		reiserfs_write_unlock(sb);
 		/* replay failed, caller must call free_journal_ram and abort
 		 ** the mount
 		 */
 		return -1;
 	}
+	reiserfs_write_unlock(sb);
 	return 0;
 }
 
@@ -2828,13 +2837,7 @@ int journal_init(struct super_block *sb,
 		goto free_and_return;
 	}
 
-	/*
-	 * Journal_read needs to be inspected in order to push down
-	 * the lock further inside (or even remove it).
-	 */
-	reiserfs_write_lock(sb);
 	ret = journal_read(sb);
-	reiserfs_write_unlock(sb);
 	if (ret < 0) {
 		reiserfs_warning(sb, "reiserfs-2006",
 				 "Replay Failure, unable to mount");
@@ -2923,9 +2926,9 @@ static void queue_log_writer(struct supe
 	add_wait_queue(&journal->j_join_wait, &wait);
 	set_current_state(TASK_UNINTERRUPTIBLE);
 	if (test_bit(J_WRITERS_QUEUED, &journal->j_state)) {
-		reiserfs_write_unlock(s);
+		int depth = reiserfs_write_unlock_nested(s);
 		schedule();
-		reiserfs_write_lock(s);
+		reiserfs_write_lock_nested(s, depth);
 	}
 	__set_current_state(TASK_RUNNING);
 	remove_wait_queue(&journal->j_join_wait, &wait);
@@ -2943,9 +2946,12 @@ static void let_transaction_grow(struct
 	struct reiserfs_journal *journal = SB_JOURNAL(sb);
 	unsigned long bcount = journal->j_bcount;
 	while (1) {
-		reiserfs_write_unlock(sb);
+		int depth;
+
+		depth = reiserfs_write_unlock_nested(sb);
 		schedule_timeout_uninterruptible(1);
-		reiserfs_write_lock(sb);
+		reiserfs_write_lock_nested(sb, depth);
+
 		journal->j_current_jl->j_state |= LIST_COMMIT_PENDING;
 		while ((atomic_read(&journal->j_wcount) > 0 ||
 			atomic_read(&journal->j_jlock)) &&
@@ -2976,6 +2982,7 @@ static int do_journal_begin_r(struct rei
 	struct reiserfs_transaction_handle myth;
 	int sched_count = 0;
 	int retval;
+	int depth;
 
 	reiserfs_check_lock_depth(sb, "journal_begin");
 	BUG_ON(nblocks > journal->j_trans_max);
@@ -2996,9 +3003,9 @@ static int do_journal_begin_r(struct rei
 
 	if (test_bit(J_WRITERS_BLOCKED, &journal->j_state)) {
 		unlock_journal(sb);
-		reiserfs_write_unlock(sb);
+		depth = reiserfs_write_unlock_nested(sb);
 		reiserfs_wait_on_write_block(sb);
-		reiserfs_write_lock(sb);
+		reiserfs_write_lock_nested(sb, depth);
 		PROC_INFO_INC(sb, journal.journal_relock_writers);
 		goto relock;
 	}
@@ -3821,6 +3828,7 @@ void reiserfs_restore_prepared_buffer(st
 	if (test_clear_buffer_journal_restore_dirty(bh) &&
 	    buffer_journal_dirty(bh)) {
 		struct reiserfs_journal_cnode *cn;
+		reiserfs_write_lock(sb);
 		cn = get_journal_hash_dev(sb,
 					  journal->j_list_hash_table,
 					  bh->b_blocknr);
@@ -3828,6 +3836,7 @@ void reiserfs_restore_prepared_buffer(st
 			set_buffer_journal_test(bh);
 			mark_buffer_dirty(bh);
 		}
+		reiserfs_write_unlock(sb);
 	}
 	clear_buffer_journal_prepared(bh);
 }
@@ -3911,6 +3920,7 @@ static int do_journal_end(struct reiserf
 	unsigned long jindex;
 	unsigned int commit_trans_id;
 	int trans_half;
+	int depth;
 
 	BUG_ON(th->t_refcount > 1);
 	BUG_ON(!th->t_trans_id);
@@ -4116,9 +4126,7 @@ static int do_journal_end(struct reiserf
 		next = cn->next;
 		free_cnode(sb, cn);
 		cn = next;
-		reiserfs_write_unlock(sb);
-		cond_resched();
-		reiserfs_write_lock(sb);
+		reiserfs_cond_resched(sb);
 	}
 
 	/* we are done  with both the c_bh and d_bh, but
@@ -4165,10 +4173,10 @@ static int do_journal_end(struct reiserf
 	 * is lost.
 	 */
 	if (!list_empty(&jl->j_tail_bh_list)) {
-		reiserfs_write_unlock(sb);
+		depth = reiserfs_write_unlock_nested(sb);
 		write_ordered_buffers(&journal->j_dirty_buffers_lock,
 				      journal, jl, &jl->j_tail_bh_list);
-		reiserfs_write_lock(sb);
+		reiserfs_write_lock_nested(sb, depth);
 	}
 	BUG_ON(!list_empty(&jl->j_tail_bh_list));
 	mutex_unlock(&jl->j_commit_mutex);
--- a/fs/reiserfs/lock.c	2013-08-07 10:23:30.205643392 -0400
+++ b/fs/reiserfs/lock.c	2013-08-07 10:23:33.973586217 -0400
@@ -48,30 +48,35 @@ void reiserfs_write_unlock(struct super_
 	}
 }
 
-/*
- * If we already own the lock, just exit and don't increase the depth.
- * Useful when we don't want to lock more than once.
- *
- * We always return the lock_depth we had before calling
- * this function.
- */
-int reiserfs_write_lock_once(struct super_block *s)
+int __must_check reiserfs_write_unlock_nested(struct super_block *s)
 {
 	struct reiserfs_sb_info *sb_i = REISERFS_SB(s);
+	int depth;
 
-	if (sb_i->lock_owner != current) {
-		mutex_lock(&sb_i->lock);
-		sb_i->lock_owner = current;
-		return sb_i->lock_depth++;
-	}
+	/* this can happen when the lock isn't always held */
+	if (sb_i->lock_owner != current)
+		return -1;
+
+	depth = sb_i->lock_depth;
 
-	return sb_i->lock_depth;
+	sb_i->lock_depth = -1;
+	sb_i->lock_owner = NULL;
+	mutex_unlock(&sb_i->lock);
+
+	return depth;
 }
 
-void reiserfs_write_unlock_once(struct super_block *s, int lock_depth)
+void reiserfs_write_lock_nested(struct super_block *s, int depth)
 {
-	if (lock_depth == -1)
-		reiserfs_write_unlock(s);
+	struct reiserfs_sb_info *sb_i = REISERFS_SB(s);
+
+	/* this can happen when the lock isn't always held */
+	if (depth == -1)
+		return;
+
+	mutex_lock(&sb_i->lock);
+	sb_i->lock_owner = current;
+	sb_i->lock_depth = depth;
 }
 
 /*
@@ -82,9 +87,7 @@ void reiserfs_check_lock_depth(struct su
 {
 	struct reiserfs_sb_info *sb_i = REISERFS_SB(sb);
 
-	if (sb_i->lock_depth < 0)
-		reiserfs_panic(sb, "%s called without kernel lock held %d",
-			       caller);
+	WARN_ON(sb_i->lock_depth < 0);
 }
 
 #ifdef CONFIG_REISERFS_CHECK
--- a/fs/reiserfs/namei.c	2013-08-07 10:23:30.205643392 -0400
+++ b/fs/reiserfs/namei.c	2013-08-07 10:23:33.985586038 -0400
@@ -325,7 +325,6 @@ static struct dentry *reiserfs_lookup(st
 				      unsigned int flags)
 {
 	int retval;
-	int lock_depth;
 	struct inode *inode = NULL;
 	struct reiserfs_dir_entry de;
 	INITIALIZE_PATH(path_to_entry);
@@ -333,12 +332,7 @@ static struct dentry *reiserfs_lookup(st
 	if (REISERFS_MAX_NAME(dir->i_sb->s_blocksize) < dentry->d_name.len)
 		return ERR_PTR(-ENAMETOOLONG);
 
-	/*
-	 * Might be called with or without the write lock, must be careful
-	 * to not recursively hold it in case we want to release the lock
-	 * before rescheduling.
-	 */
-	lock_depth = reiserfs_write_lock_once(dir->i_sb);
+	reiserfs_write_lock(dir->i_sb);
 
 	de.de_gen_number_bit_string = NULL;
 	retval =
@@ -349,7 +343,7 @@ static struct dentry *reiserfs_lookup(st
 		inode = reiserfs_iget(dir->i_sb,
 				      (struct cpu_key *)&(de.de_dir_id));
 		if (!inode || IS_ERR(inode)) {
-			reiserfs_write_unlock_once(dir->i_sb, lock_depth);
+			reiserfs_write_unlock(dir->i_sb);
 			return ERR_PTR(-EACCES);
 		}
 
@@ -358,7 +352,7 @@ static struct dentry *reiserfs_lookup(st
 		if (IS_PRIVATE(dir))
 			inode->i_flags |= S_PRIVATE;
 	}
-	reiserfs_write_unlock_once(dir->i_sb, lock_depth);
+	reiserfs_write_unlock(dir->i_sb);
 	if (retval == IO_ERROR) {
 		return ERR_PTR(-EIO);
 	}
@@ -727,7 +721,6 @@ static int reiserfs_mkdir(struct inode *
 	struct inode *inode;
 	struct reiserfs_transaction_handle th;
 	struct reiserfs_security_handle security;
-	int lock_depth;
 	/* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */
 	int jbegin_count =
 	    JOURNAL_PER_BALANCE_CNT * 3 +
@@ -753,7 +746,7 @@ static int reiserfs_mkdir(struct inode *
 		return retval;
 	}
 	jbegin_count += retval;
-	lock_depth = reiserfs_write_lock_once(dir->i_sb);
+	reiserfs_write_lock(dir->i_sb);
 
 	retval = journal_begin(&th, dir->i_sb, jbegin_count);
 	if (retval) {
@@ -804,7 +797,7 @@ static int reiserfs_mkdir(struct inode *
 	d_instantiate(dentry, inode);
 	retval = journal_end(&th, dir->i_sb, jbegin_count);
 out_failed:
-	reiserfs_write_unlock_once(dir->i_sb, lock_depth);
+	reiserfs_write_unlock(dir->i_sb);
 	return retval;
 }
 
@@ -920,7 +913,6 @@ static int reiserfs_unlink(struct inode
 	struct reiserfs_transaction_handle th;
 	int jbegin_count;
 	unsigned long savelink;
-	int depth;
 
 	dquot_initialize(dir);
 
@@ -934,7 +926,7 @@ static int reiserfs_unlink(struct inode
 	    JOURNAL_PER_BALANCE_CNT * 2 + 2 +
 	    4 * REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb);
 
-	depth = reiserfs_write_lock_once(dir->i_sb);
+	reiserfs_write_lock(dir->i_sb);
 	retval = journal_begin(&th, dir->i_sb, jbegin_count);
 	if (retval)
 		goto out_unlink;
@@ -995,7 +987,7 @@ static int reiserfs_unlink(struct inode
 
 	retval = journal_end(&th, dir->i_sb, jbegin_count);
 	reiserfs_check_path(&path);
-	reiserfs_write_unlock_once(dir->i_sb, depth);
+	reiserfs_write_unlock(dir->i_sb);
 	return retval;
 
       end_unlink:
@@ -1005,7 +997,7 @@ static int reiserfs_unlink(struct inode
 	if (err)
 		retval = err;
       out_unlink:
-	reiserfs_write_unlock_once(dir->i_sb, depth);
+	reiserfs_write_unlock(dir->i_sb);
 	return retval;
 }
 
--- a/fs/reiserfs/prints.c	2013-08-07 10:23:30.205643392 -0400
+++ b/fs/reiserfs/prints.c	2013-08-07 10:23:33.997585854 -0400
@@ -358,12 +358,13 @@ void __reiserfs_panic(struct super_block
 	dump_stack();
 #endif
 	if (sb)
-		panic(KERN_WARNING "REISERFS panic (device %s): %s%s%s: %s\n",
+		printk(KERN_WARNING "REISERFS panic (device %s): %s%s%s: %s\n",
 		      sb->s_id, id ? id : "", id ? " " : "",
 		      function, error_buf);
 	else
-		panic(KERN_WARNING "REISERFS panic: %s%s%s: %s\n",
+		printk(KERN_WARNING "REISERFS panic: %s%s%s: %s\n",
 		      id ? id : "", id ? " " : "", function, error_buf);
+	BUG();
 }
 
 void __reiserfs_error(struct super_block *sb, const char *id,
--- a/fs/reiserfs/reiserfs.h	2013-08-07 10:23:30.205643392 -0400
+++ b/fs/reiserfs/reiserfs.h	2013-08-07 10:23:34.013585612 -0400
@@ -630,8 +630,8 @@ static inline int __reiserfs_is_journal_
  */
 void reiserfs_write_lock(struct super_block *s);
 void reiserfs_write_unlock(struct super_block *s);
-int reiserfs_write_lock_once(struct super_block *s);
-void reiserfs_write_unlock_once(struct super_block *s, int lock_depth);
+int __must_check reiserfs_write_unlock_nested(struct super_block *s);
+void reiserfs_write_lock_nested(struct super_block *s, int depth);
 
 #ifdef CONFIG_REISERFS_CHECK
 void reiserfs_lock_check_recursive(struct super_block *s);
@@ -667,31 +667,33 @@ static inline void reiserfs_lock_check_r
  * - The inode mutex
  */
 static inline void reiserfs_mutex_lock_safe(struct mutex *m,
-			       struct super_block *s)
+					    struct super_block *s)
 {
-	reiserfs_lock_check_recursive(s);
-	reiserfs_write_unlock(s);
+	int depth;
+
+	depth = reiserfs_write_unlock_nested(s);
 	mutex_lock(m);
-	reiserfs_write_lock(s);
+	reiserfs_write_lock_nested(s, depth);
 }
 
 static inline void
 reiserfs_mutex_lock_nested_safe(struct mutex *m, unsigned int subclass,
-			       struct super_block *s)
+				struct super_block *s)
 {
-	reiserfs_lock_check_recursive(s);
-	reiserfs_write_unlock(s);
+	int depth;
+
+	depth = reiserfs_write_unlock_nested(s);
 	mutex_lock_nested(m, subclass);
-	reiserfs_write_lock(s);
+	reiserfs_write_lock_nested(s, depth);
 }
 
 static inline void
 reiserfs_down_read_safe(struct rw_semaphore *sem, struct super_block *s)
 {
-	reiserfs_lock_check_recursive(s);
-	reiserfs_write_unlock(s);
-	down_read(sem);
-	reiserfs_write_lock(s);
+       int depth;
+       depth = reiserfs_write_unlock_nested(s);
+       down_read(sem);
+       reiserfs_write_lock_nested(s, depth);
 }
 
 /*
@@ -701,9 +703,11 @@ reiserfs_down_read_safe(struct rw_semaph
 static inline void reiserfs_cond_resched(struct super_block *s)
 {
 	if (need_resched()) {
-		reiserfs_write_unlock(s);
+		int depth;
+
+		depth = reiserfs_write_unlock_nested(s);
 		schedule();
-		reiserfs_write_lock(s);
+		reiserfs_write_lock_nested(s, depth);
 	}
 }
 
--- a/fs/reiserfs/resize.c	2013-08-07 10:23:30.205643392 -0400
+++ b/fs/reiserfs/resize.c	2013-08-07 10:23:34.025585431 -0400
@@ -34,6 +34,7 @@ int reiserfs_resize(struct super_block *
 	unsigned long int block_count, free_blocks;
 	int i;
 	int copy_size;
+	int depth;
 
 	sb = SB_DISK_SUPER_BLOCK(s);
 
@@ -43,7 +44,9 @@ int reiserfs_resize(struct super_block *
 	}
 
 	/* check the device size */
+	depth = reiserfs_write_unlock_nested(s);
 	bh = sb_bread(s, block_count_new - 1);
+	reiserfs_write_lock_nested(s, depth);
 	if (!bh) {
 		printk("reiserfs_resize: can\'t read last block\n");
 		return -EINVAL;
@@ -125,9 +128,12 @@ int reiserfs_resize(struct super_block *
 		 * transaction begins, and the new bitmaps don't matter if the
 		 * transaction fails. */
 		for (i = bmap_nr; i < bmap_nr_new; i++) {
+			int depth;
 			/* don't use read_bitmap_block since it will cache
 			 * the uninitialized bitmap */
+			depth = reiserfs_write_unlock_nested(s);
 			bh = sb_bread(s, i * s->s_blocksize * 8);
+			reiserfs_write_lock_nested(s, depth);
 			if (!bh) {
 				vfree(bitmap);
 				return -EIO;
@@ -138,9 +144,9 @@ int reiserfs_resize(struct super_block *
 
 			set_buffer_uptodate(bh);
 			mark_buffer_dirty(bh);
-			reiserfs_write_unlock(s);
+			depth = reiserfs_write_unlock_nested(s);
 			sync_dirty_buffer(bh);
-			reiserfs_write_lock(s);
+			reiserfs_write_lock_nested(s, depth);
 			// update bitmap_info stuff
 			bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
 			brelse(bh);
--- a/fs/reiserfs/stree.c	2013-08-07 10:23:30.205643392 -0400
+++ b/fs/reiserfs/stree.c	2013-08-07 10:23:34.037585247 -0400
@@ -550,7 +550,8 @@ static bool search_by_key_reada(struct s
 		 */
 		if (!buffer_uptodate(bh[j])) {
 			if (!unlocked) {
-				reiserfs_write_unlock(s);
+				int depth = -1; /* avoiding __must_check */
+				depth = reiserfs_write_unlock_nested(s);
 				unlocked = true;
 			}
 			ll_rw_block(READA, 1, bh + j);
@@ -625,7 +626,7 @@ int search_by_key(struct super_block *sb
 	block_number = SB_ROOT_BLOCK(sb);
 	expected_level = -1;
 	while (1) {
-
+		int depth;
 #ifdef CONFIG_REISERFS_CHECK
 		if (!(++repeat_counter % 50000))
 			reiserfs_warning(sb, "PAP-5100",
@@ -646,25 +647,26 @@ int search_by_key(struct super_block *sb
 		if ((bh = last_element->pe_buffer =
 		     sb_getblk(sb, block_number))) {
 			bool unlocked = false;
-
+			depth = REISERFS_SB(sb)->lock_depth;
 			if (!buffer_uptodate(bh) && reada_count > 1)
 				/* may unlock the write lock */
 				unlocked = search_by_key_reada(sb, reada_bh,
 						    reada_blocks, reada_count);
+
 			/*
 			 * If we haven't already unlocked the write lock,
 			 * then we need to do that here before reading
 			 * the current block
 			 */
 			if (!buffer_uptodate(bh) && !unlocked) {
-				reiserfs_write_unlock(sb);
+				depth = reiserfs_write_unlock_nested(sb);
 				unlocked = true;
 			}
 			ll_rw_block(READ, 1, &bh);
 			wait_on_buffer(bh);
 
 			if (unlocked)
-				reiserfs_write_lock(sb);
+				reiserfs_write_lock_nested(sb, depth);
 			if (!buffer_uptodate(bh))
 				goto io_error;
 		} else {
@@ -1059,9 +1061,7 @@ static char prepare_for_delete_or_cut(st
 			reiserfs_free_block(th, inode, block, 1);
 		    }
 
-		    reiserfs_write_unlock(sb);
-		    cond_resched();
-		    reiserfs_write_lock(sb);
+		    reiserfs_cond_resched(sb);
 
 		    if (item_moved (&s_ih, path))  {
 			need_re_search = 1;
--- a/fs/reiserfs/super.c	2013-08-07 10:23:31.637621664 -0400
+++ b/fs/reiserfs/super.c	2013-08-07 10:23:34.049585066 -0400
@@ -624,7 +624,6 @@ static void reiserfs_dirty_inode(struct
 	struct reiserfs_transaction_handle th;
 
 	int err = 0;
-	int lock_depth;
 
 	if (inode->i_sb->s_flags & MS_RDONLY) {
 		reiserfs_warning(inode->i_sb, "clm-6006",
@@ -632,7 +631,7 @@ static void reiserfs_dirty_inode(struct
 				 inode->i_ino);
 		return;
 	}
-	lock_depth = reiserfs_write_lock_once(inode->i_sb);
+	reiserfs_write_lock(inode->i_sb);
 
 	/* this is really only used for atime updates, so they don't have
 	 ** to be included in O_SYNC or fsync
@@ -645,7 +644,7 @@ static void reiserfs_dirty_inode(struct
 	journal_end(&th, inode->i_sb, 1);
 
 out:
-	reiserfs_write_unlock_once(inode->i_sb, lock_depth);
+	reiserfs_write_unlock(inode->i_sb);
 }
 
 static int reiserfs_show_options(struct seq_file *seq, struct dentry *root)

Re: [patch v3 2/3] reiserfs: locking, handle nested locks properly

[Jan Kara]

On Wed 07-08-13 12:35:17, Jeff Mahoney wrote:
> The reiserfs write lock replaced the BKL and uses similar semantics.
> 
> Frederic's locking code makes a distinction between when the lock is nested
> and when it's being acquired/released, but I don't think that's the right
> distinction to make.
> 
> The right distinction is between the lock being released at end-of-use and
> the lock being released for a schedule. The unlock should return the depth
> and the lock should restore it, rather than the other way around as it is now.
> 
> This patch implements that and adds a number of places where the lock
> should be dropped.
> 
> Signed-off-by: Jeff Mahoney <jeffm@suse.com>
> ---
> 
>  fs/reiserfs/bitmap.c   |    5 +-
>  fs/reiserfs/dir.c      |    7 +--
>  fs/reiserfs/fix_node.c |   26 ++++++------
>  fs/reiserfs/inode.c    |   77 ++++++++++++++++--------------------
>  fs/reiserfs/ioctl.c    |    7 +--
>  fs/reiserfs/journal.c  |  104 ++++++++++++++++++++++++++-----------------------
>  fs/reiserfs/lock.c     |   43 ++++++++++----------
>  fs/reiserfs/namei.c    |   24 +++--------
>  fs/reiserfs/prints.c   |    5 +-
>  fs/reiserfs/reiserfs.h |   36 +++++++++-------
>  fs/reiserfs/resize.c   |   10 +++-
>  fs/reiserfs/stree.c    |   16 +++----
>  fs/reiserfs/super.c    |    5 --
>  13 files changed, 188 insertions(+), 177 deletions(-)
> 
  Just one smaller comment below, otherwise the patch looks good.

> --- a/fs/reiserfs/stree.c	2013-08-07 10:23:30.205643392 -0400
> +++ b/fs/reiserfs/stree.c	2013-08-07 10:23:34.037585247 -0400
> @@ -550,7 +550,8 @@ static bool search_by_key_reada(struct s
>  		 */
>  		if (!buffer_uptodate(bh[j])) {
>  			if (!unlocked) {
> -				reiserfs_write_unlock(s);
> +				int depth = -1; /* avoiding __must_check */
> +				depth = reiserfs_write_unlock_nested(s);
>  				unlocked = true;
>  			}
>  			ll_rw_block(READA, 1, bh + j);
  This is ugly. It shouldn't be too hard to either modify
search_by_key_reada() to return lock depth or wrap more from the callsite
of search_by_key_reada() into the function so that it always returns with
write lock locked...

> @@ -625,7 +626,7 @@ int search_by_key(struct super_block *sb
>  	block_number = SB_ROOT_BLOCK(sb);
>  	expected_level = -1;
>  	while (1) {
> -
> +		int depth;
>  #ifdef CONFIG_REISERFS_CHECK
>  		if (!(++repeat_counter % 50000))
>  			reiserfs_warning(sb, "PAP-5100",
> @@ -646,25 +647,26 @@ int search_by_key(struct super_block *sb
>  		if ((bh = last_element->pe_buffer =
>  		     sb_getblk(sb, block_number))) {
>  			bool unlocked = false;
> -
> +			depth = REISERFS_SB(sb)->lock_depth;
>  			if (!buffer_uptodate(bh) && reada_count > 1)
>  				/* may unlock the write lock */
>  				unlocked = search_by_key_reada(sb, reada_bh,
>  						    reada_blocks, reada_count);
> +
>  			/*
>  			 * If we haven't already unlocked the write lock,
>  			 * then we need to do that here before reading
>  			 * the current block
>  			 */
>  			if (!buffer_uptodate(bh) && !unlocked) {
> -				reiserfs_write_unlock(sb);
> +				depth = reiserfs_write_unlock_nested(sb);
>  				unlocked = true;
>  			}
>  			ll_rw_block(READ, 1, &bh);
>  			wait_on_buffer(bh);
>  
>  			if (unlocked)
> -				reiserfs_write_lock(sb);
> +				reiserfs_write_lock_nested(sb, depth);
>  			if (!buffer_uptodate(bh))
>  				goto io_error;
>  		} else {

								Honza
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR

Re: [patch v3 2/3] reiserfs: locking, handle nested locks properly

[Jeff Mahoney]

[-- Attachment #1: Type: text/plain, Size: 3817 bytes --]

On 8/7/13 4:25 PM, Jan Kara wrote:
> On Wed 07-08-13 12:35:17, Jeff Mahoney wrote:
>> The reiserfs write lock replaced the BKL and uses similar semantics.
>>
>> Frederic's locking code makes a distinction between when the lock is nested
>> and when it's being acquired/released, but I don't think that's the right
>> distinction to make.
>>
>> The right distinction is between the lock being released at end-of-use and
>> the lock being released for a schedule. The unlock should return the depth
>> and the lock should restore it, rather than the other way around as it is now.
>>
>> This patch implements that and adds a number of places where the lock
>> should be dropped.
>>
>> Signed-off-by: Jeff Mahoney <jeffm@suse.com>
>> ---
>>
>>  fs/reiserfs/bitmap.c   |    5 +-
>>  fs/reiserfs/dir.c      |    7 +--
>>  fs/reiserfs/fix_node.c |   26 ++++++------
>>  fs/reiserfs/inode.c    |   77 ++++++++++++++++--------------------
>>  fs/reiserfs/ioctl.c    |    7 +--
>>  fs/reiserfs/journal.c  |  104 ++++++++++++++++++++++++++-----------------------
>>  fs/reiserfs/lock.c     |   43 ++++++++++----------
>>  fs/reiserfs/namei.c    |   24 +++--------
>>  fs/reiserfs/prints.c   |    5 +-
>>  fs/reiserfs/reiserfs.h |   36 +++++++++-------
>>  fs/reiserfs/resize.c   |   10 +++-
>>  fs/reiserfs/stree.c    |   16 +++----
>>  fs/reiserfs/super.c    |    5 --
>>  13 files changed, 188 insertions(+), 177 deletions(-)
>>
>   Just one smaller comment below, otherwise the patch looks good.
> 
>> --- a/fs/reiserfs/stree.c	2013-08-07 10:23:30.205643392 -0400
>> +++ b/fs/reiserfs/stree.c	2013-08-07 10:23:34.037585247 -0400
>> @@ -550,7 +550,8 @@ static bool search_by_key_reada(struct s
>>  		 */
>>  		if (!buffer_uptodate(bh[j])) {
>>  			if (!unlocked) {
>> -				reiserfs_write_unlock(s);
>> +				int depth = -1; /* avoiding __must_check */
>> +				depth = reiserfs_write_unlock_nested(s);
>>  				unlocked = true;
>>  			}
>>  			ll_rw_block(READA, 1, bh + j);
>   This is ugly. It shouldn't be too hard to either modify
> search_by_key_reada() to return lock depth or wrap more from the callsite
> of search_by_key_reada() into the function so that it always returns with
> write lock locked...

Ok, I'll return lock depth instead. Dropping the lock is an operation
that may happen but doesn't always happen. Pulling more in (or pushing
it out) won't affect the complexity there.

-Jeff

>> @@ -625,7 +626,7 @@ int search_by_key(struct super_block *sb
>>  	block_number = SB_ROOT_BLOCK(sb);
>>  	expected_level = -1;
>>  	while (1) {
>> -
>> +		int depth;
>>  #ifdef CONFIG_REISERFS_CHECK
>>  		if (!(++repeat_counter % 50000))
>>  			reiserfs_warning(sb, "PAP-5100",
>> @@ -646,25 +647,26 @@ int search_by_key(struct super_block *sb
>>  		if ((bh = last_element->pe_buffer =
>>  		     sb_getblk(sb, block_number))) {
>>  			bool unlocked = false;
>> -
>> +			depth = REISERFS_SB(sb)->lock_depth;
>>  			if (!buffer_uptodate(bh) && reada_count > 1)
>>  				/* may unlock the write lock */
>>  				unlocked = search_by_key_reada(sb, reada_bh,
>>  						    reada_blocks, reada_count);
>> +
>>  			/*
>>  			 * If we haven't already unlocked the write lock,
>>  			 * then we need to do that here before reading
>>  			 * the current block
>>  			 */
>>  			if (!buffer_uptodate(bh) && !unlocked) {
>> -				reiserfs_write_unlock(sb);
>> +				depth = reiserfs_write_unlock_nested(sb);
>>  				unlocked = true;
>>  			}
>>  			ll_rw_block(READ, 1, &bh);
>>  			wait_on_buffer(bh);
>>  
>>  			if (unlocked)
>> -				reiserfs_write_lock(sb);
>> +				reiserfs_write_lock_nested(sb, depth);
>>  			if (!buffer_uptodate(bh))
>>  				goto io_error;
>>  		} else {
> 
> 								Honza
> 


-- 
Jeff Mahoney
SUSE Labs


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 841 bytes --]

[patch v3 3/3] reiserfs: locking, release lock around quota operations

[Jeff Mahoney]

[-- Attachment #1: reiserfs/reiserfs-locking-release-lock-around-quota-operations --]
[-- Type: text/plain, Size: 12820 bytes --]

Previous commits released the write lock across quota operations but
missed several places.  In particular, the free operations can also
call into the file system code and take the write lock, causing
deadlocks.

This patch introduces some more helpers and uses them for quota call
sites.  Without this patch applied, reiserfs + quotas runs into deadlocks
under anything more than trivial load.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
---

 fs/reiserfs/bitmap.c |   17 +++++++++++++++--
 fs/reiserfs/inode.c  |   19 +++++++++++--------
 fs/reiserfs/stree.c  |   28 +++++++++++++++++++++++-----
 fs/reiserfs/super.c  |   22 ++++++++++++++--------
 4 files changed, 63 insertions(+), 23 deletions(-)

--- a/fs/reiserfs/bitmap.c	2013-08-07 10:23:33.885587547 -0400
+++ b/fs/reiserfs/bitmap.c	2013-08-07 10:23:35.761559089 -0400
@@ -423,8 +423,11 @@ static void _reiserfs_free_block(struct
 	set_sb_free_blocks(rs, sb_free_blocks(rs) + 1);
 
 	journal_mark_dirty(th, s, sbh);
-	if (for_unformatted)
+	if (for_unformatted) {
+		int depth = reiserfs_write_unlock_nested(s);
 		dquot_free_block_nodirty(inode, 1);
+		reiserfs_write_lock_nested(s, depth);
+	}
 }
 
 void reiserfs_free_block(struct reiserfs_transaction_handle *th,
@@ -1128,6 +1131,7 @@ static inline int blocknrs_and_prealloc_
 	b_blocknr_t finish = SB_BLOCK_COUNT(s) - 1;
 	int passno = 0;
 	int nr_allocated = 0;
+	int depth;
 
 	determine_prealloc_size(hint);
 	if (!hint->formatted_node) {
@@ -1137,10 +1141,13 @@ static inline int blocknrs_and_prealloc_
 			       "reiserquota: allocating %d blocks id=%u",
 			       amount_needed, hint->inode->i_uid);
 #endif
+		depth = reiserfs_write_unlock_nested(s);
 		quota_ret =
 		    dquot_alloc_block_nodirty(hint->inode, amount_needed);
-		if (quota_ret)	/* Quota exceeded? */
+		if (quota_ret) {	/* Quota exceeded? */
+			reiserfs_write_lock_nested(s, depth);
 			return QUOTA_EXCEEDED;
+		}
 		if (hint->preallocate && hint->prealloc_size) {
 #ifdef REISERQUOTA_DEBUG
 			reiserfs_debug(s, REISERFS_DEBUG_CODE,
@@ -1153,6 +1160,7 @@ static inline int blocknrs_and_prealloc_
 				hint->preallocate = hint->prealloc_size = 0;
 		}
 		/* for unformatted nodes, force large allocations */
+		reiserfs_write_lock_nested(s, depth);
 	}
 
 	do {
@@ -1181,9 +1189,11 @@ static inline int blocknrs_and_prealloc_
 					       hint->inode->i_uid);
 #endif
 				/* Free not allocated blocks */
+				depth = reiserfs_write_unlock_nested(s);
 				dquot_free_block_nodirty(hint->inode,
 					amount_needed + hint->prealloc_size -
 					nr_allocated);
+				reiserfs_write_lock_nested(s, depth);
 			}
 			while (nr_allocated--)
 				reiserfs_free_block(hint->th, hint->inode,
@@ -1214,10 +1224,13 @@ static inline int blocknrs_and_prealloc_
 			       REISERFS_I(hint->inode)->i_prealloc_count,
 			       hint->inode->i_uid);
 #endif
+
+		depth = reiserfs_write_unlock_nested(s);
 		dquot_free_block_nodirty(hint->inode, amount_needed +
 					 hint->prealloc_size - nr_allocated -
 					 REISERFS_I(hint->inode)->
 					 i_prealloc_count);
+		reiserfs_write_lock_nested(s, depth);
 	}
 
 	return CARRY_ON;
--- a/fs/reiserfs/inode.c	2013-08-07 10:23:33.933586826 -0400
+++ b/fs/reiserfs/inode.c	2013-08-07 10:23:35.781558786 -0400
@@ -57,8 +57,11 @@ void reiserfs_evict_inode(struct inode *
 		/* Do quota update inside a transaction for journaled quotas. We must do that
 		 * after delete_object so that quota updates go into the same transaction as
 		 * stat data deletion */
-		if (!err) 
+		if (!err) {
+			int depth = reiserfs_write_unlock_nested(inode->i_sb);
 			dquot_free_inode(inode);
+			reiserfs_write_lock_nested(inode->i_sb, depth);
+		}
 
 		if (journal_end(&th, inode->i_sb, jbegin_count))
 			goto out;
@@ -1768,7 +1771,7 @@ int reiserfs_new_inode(struct reiserfs_t
 		       struct inode *inode,
 		       struct reiserfs_security_handle *security)
 {
-	struct super_block *sb;
+	struct super_block *sb = dir->i_sb;
 	struct reiserfs_iget_args args;
 	INITIALIZE_PATH(path_to_key);
 	struct cpu_key key;
@@ -1780,9 +1783,9 @@ int reiserfs_new_inode(struct reiserfs_t
 
 	BUG_ON(!th->t_trans_id);
 
-	reiserfs_write_unlock(inode->i_sb);
+	depth = reiserfs_write_unlock_nested(sb);
 	err = dquot_alloc_inode(inode);
-	reiserfs_write_lock(inode->i_sb);
+	reiserfs_write_lock_nested(sb, depth);
 	if (err)
 		goto out_end_trans;
 	if (!dir->i_nlink) {
@@ -1790,8 +1793,6 @@ int reiserfs_new_inode(struct reiserfs_t
 		goto out_bad_inode;
 	}
 
-	sb = dir->i_sb;
-
 	/* item head of new item */
 	ih.ih_key.k_dir_id = reiserfs_choose_packing(dir);
 	ih.ih_key.k_objectid = cpu_to_le32(reiserfs_get_unused_objectid(th));
@@ -1983,14 +1984,16 @@ int reiserfs_new_inode(struct reiserfs_t
 	INODE_PKEY(inode)->k_objectid = 0;
 
 	/* Quota change must be inside a transaction for journaling */
+	depth = reiserfs_write_unlock_nested(inode->i_sb);
 	dquot_free_inode(inode);
+	reiserfs_write_lock_nested(inode->i_sb, depth);
 
       out_end_trans:
 	journal_end(th, th->t_super, th->t_blocks_allocated);
-	reiserfs_write_unlock(inode->i_sb);
 	/* Drop can be outside and it needs more credits so it's better to have it outside */
+	depth = reiserfs_write_unlock_nested(inode->i_sb);
 	dquot_drop(inode);
-	reiserfs_write_lock(inode->i_sb);
+	reiserfs_write_lock_nested(inode->i_sb, depth);
 	inode->i_flags |= S_NOQUOTA;
 	make_bad_inode(inode);
 
--- a/fs/reiserfs/stree.c	2013-08-07 10:23:34.037585247 -0400
+++ b/fs/reiserfs/stree.c	2013-08-07 10:23:35.793558603 -0400
@@ -1190,6 +1190,7 @@ int reiserfs_delete_item(struct reiserfs
 	struct item_head *q_ih;
 	int quota_cut_bytes;
 	int ret_value, del_size, removed;
+	int depth;
 
 #ifdef CONFIG_REISERFS_CHECK
 	char mode;
@@ -1299,7 +1300,9 @@ int reiserfs_delete_item(struct reiserfs
 		       "reiserquota delete_item(): freeing %u, id=%u type=%c",
 		       quota_cut_bytes, inode->i_uid, head2type(&s_ih));
 #endif
+	depth = reiserfs_write_unlock_nested(inode->i_sb);
 	dquot_free_space_nodirty(inode, quota_cut_bytes);
+	reiserfs_write_lock_nested(inode->i_sb, depth);
 
 	/* Return deleted body length */
 	return ret_value;
@@ -1325,6 +1328,7 @@ int reiserfs_delete_item(struct reiserfs
 void reiserfs_delete_solid_item(struct reiserfs_transaction_handle *th,
 				struct inode *inode, struct reiserfs_key *key)
 {
+	struct super_block *sb = th->t_super;
 	struct tree_balance tb;
 	INITIALIZE_PATH(path);
 	int item_len = 0;
@@ -1377,14 +1381,17 @@ void reiserfs_delete_solid_item(struct r
 		if (retval == CARRY_ON) {
 			do_balance(&tb, NULL, NULL, M_DELETE);
 			if (inode) {	/* Should we count quota for item? (we don't count quotas for save-links) */
+				int depth;
 #ifdef REISERQUOTA_DEBUG
 				reiserfs_debug(th->t_super, REISERFS_DEBUG_CODE,
 					       "reiserquota delete_solid_item(): freeing %u id=%u type=%c",
 					       quota_cut_bytes, inode->i_uid,
 					       key2type(key));
 #endif
+				depth = reiserfs_write_unlock_nested(sb);
 				dquot_free_space_nodirty(inode,
 							 quota_cut_bytes);
+				reiserfs_write_lock_nested(sb, depth);
 			}
 			break;
 		}
@@ -1561,6 +1568,7 @@ int reiserfs_cut_from_item(struct reiser
 	int retval2 = -1;
 	int quota_cut_bytes;
 	loff_t tail_pos = 0;
+	int depth;
 
 	BUG_ON(!th->t_trans_id);
 
@@ -1733,7 +1741,9 @@ int reiserfs_cut_from_item(struct reiser
 		       "reiserquota cut_from_item(): freeing %u id=%u type=%c",
 		       quota_cut_bytes, inode->i_uid, '?');
 #endif
+	depth = reiserfs_write_unlock_nested(sb);
 	dquot_free_space_nodirty(inode, quota_cut_bytes);
+	reiserfs_write_lock_nested(sb, depth);
 	return ret_value;
 }
 
@@ -1953,9 +1963,11 @@ int reiserfs_paste_into_item(struct reis
 			     const char *body,	/* Pointer to the bytes to paste.    */
 			     int pasted_size)
 {				/* Size of pasted bytes.             */
+	struct super_block *sb = inode->i_sb;
 	struct tree_balance s_paste_balance;
 	int retval;
 	int fs_gen;
+	int depth;
 
 	BUG_ON(!th->t_trans_id);
 
@@ -1968,9 +1980,9 @@ int reiserfs_paste_into_item(struct reis
 		       key2type(&(key->on_disk_key)));
 #endif
 
-	reiserfs_write_unlock(inode->i_sb);
+	depth = reiserfs_write_unlock_nested(sb);
 	retval = dquot_alloc_space_nodirty(inode, pasted_size);
-	reiserfs_write_lock(inode->i_sb);
+	reiserfs_write_lock_nested(sb, depth);
 	if (retval) {
 		pathrelse(search_path);
 		return retval;
@@ -2027,7 +2039,9 @@ int reiserfs_paste_into_item(struct reis
 		       pasted_size, inode->i_uid,
 		       key2type(&(key->on_disk_key)));
 #endif
+	depth = reiserfs_write_unlock_nested(sb);
 	dquot_free_space_nodirty(inode, pasted_size);
+	reiserfs_write_lock_nested(sb, depth);
 	return retval;
 }
 
@@ -2050,6 +2064,7 @@ int reiserfs_insert_item(struct reiserfs
 	BUG_ON(!th->t_trans_id);
 
 	if (inode) {		/* Do we count quotas for item? */
+		int depth;
 		fs_gen = get_generation(inode->i_sb);
 		quota_bytes = ih_item_len(ih);
 
@@ -2063,11 +2078,11 @@ int reiserfs_insert_item(struct reiserfs
 			       "reiserquota insert_item(): allocating %u id=%u type=%c",
 			       quota_bytes, inode->i_uid, head2type(ih));
 #endif
-		reiserfs_write_unlock(inode->i_sb);
 		/* We can't dirty inode here. It would be immediately written but
 		 * appropriate stat item isn't inserted yet... */
+		depth = reiserfs_write_unlock_nested(inode->i_sb);
 		retval = dquot_alloc_space_nodirty(inode, quota_bytes);
-		reiserfs_write_lock(inode->i_sb);
+		reiserfs_write_lock_nested(inode->i_sb, depth);
 		if (retval) {
 			pathrelse(path);
 			return retval;
@@ -2118,7 +2133,10 @@ int reiserfs_insert_item(struct reiserfs
 		       "reiserquota insert_item(): freeing %u id=%u type=%c",
 		       quota_bytes, inode->i_uid, head2type(ih));
 #endif
-	if (inode)
+	if (inode) {
+		int depth = reiserfs_write_unlock_nested(inode->i_sb);
 		dquot_free_space_nodirty(inode, quota_bytes);
+		reiserfs_write_lock_nested(inode->i_sb, depth);
+	}
 	return retval;
 }
--- a/fs/reiserfs/super.c	2013-08-07 10:23:34.049585066 -0400
+++ b/fs/reiserfs/super.c	2013-08-07 10:23:35.805558422 -0400
@@ -243,6 +243,7 @@ static int finish_unfinished(struct supe
 	done = 0;
 	REISERFS_SB(s)->s_is_unlinked_ok = 1;
 	while (!retval) {
+		int depth;
 		retval = search_item(s, &max_cpu_key, &path);
 		if (retval != ITEM_NOT_FOUND) {
 			reiserfs_error(s, "vs-2140",
@@ -298,9 +299,9 @@ static int finish_unfinished(struct supe
 			retval = remove_save_link_only(s, &save_link_key, 0);
 			continue;
 		}
-		reiserfs_write_unlock(s);
+		depth = reiserfs_write_unlock_nested(inode->i_sb);
 		dquot_initialize(inode);
-		reiserfs_write_lock(s);
+		reiserfs_write_lock_nested(inode->i_sb, depth);
 
 		if (truncate && S_ISDIR(inode->i_mode)) {
 			/* We got a truncate request for a dir which is impossible.
@@ -356,10 +357,12 @@ static int finish_unfinished(struct supe
 
 #ifdef CONFIG_QUOTA
 	/* Turn quotas off */
+	reiserfs_write_unlock(s);
 	for (i = 0; i < MAXQUOTAS; i++) {
 		if (sb_dqopt(s)->files[i] && quota_enabled[i])
 			dquot_quota_off(s, i);
 	}
+	reiserfs_write_lock(s);
 	if (ms_active_set)
 		/* Restore the flag back */
 		s->s_flags &= ~MS_ACTIVE;
@@ -2098,6 +2101,7 @@ static int reiserfs_write_dquot(struct d
 {
 	struct reiserfs_transaction_handle th;
 	int ret, err;
+	int depth;
 
 	reiserfs_write_lock(dquot->dq_sb);
 	ret =
@@ -2105,9 +2109,9 @@ static int reiserfs_write_dquot(struct d
 			  REISERFS_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
 	if (ret)
 		goto out;
-	reiserfs_write_unlock(dquot->dq_sb);
+	depth = reiserfs_write_unlock_nested(dquot->dq_sb);
 	ret = dquot_commit(dquot);
-	reiserfs_write_lock(dquot->dq_sb);
+	reiserfs_write_lock_nested(dquot->dq_sb, depth);
 	err =
 	    journal_end(&th, dquot->dq_sb,
 			REISERFS_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
@@ -2122,6 +2126,7 @@ static int reiserfs_acquire_dquot(struct
 {
 	struct reiserfs_transaction_handle th;
 	int ret, err;
+	int depth;
 
 	reiserfs_write_lock(dquot->dq_sb);
 	ret =
@@ -2129,9 +2134,9 @@ static int reiserfs_acquire_dquot(struct
 			  REISERFS_QUOTA_INIT_BLOCKS(dquot->dq_sb));
 	if (ret)
 		goto out;
-	reiserfs_write_unlock(dquot->dq_sb);
+	depth = reiserfs_write_unlock_nested(dquot->dq_sb);
 	ret = dquot_acquire(dquot);
-	reiserfs_write_lock(dquot->dq_sb);
+	reiserfs_write_lock_nested(dquot->dq_sb, depth);
 	err =
 	    journal_end(&th, dquot->dq_sb,
 			REISERFS_QUOTA_INIT_BLOCKS(dquot->dq_sb));
@@ -2184,15 +2189,16 @@ static int reiserfs_write_info(struct su
 {
 	struct reiserfs_transaction_handle th;
 	int ret, err;
+	int depth;
 
 	/* Data block + inode block */
 	reiserfs_write_lock(sb);
 	ret = journal_begin(&th, sb, 2);
 	if (ret)
 		goto out;
-	reiserfs_write_unlock(sb);
+	depth = reiserfs_write_unlock_nested(sb);
 	ret = dquot_commit_info(sb, type);
-	reiserfs_write_lock(sb);
+	reiserfs_write_lock_nested(sb, depth);
 	err = journal_end(&th, sb, 2);
 	if (!ret && err)
 		ret = err;

Re: [patch v3 3/3] reiserfs: locking, release lock around quota operations

[Jan Kara]

On Wed 07-08-13 12:35:18, Jeff Mahoney wrote:
> Previous commits released the write lock across quota operations but
> missed several places.  In particular, the free operations can also
> call into the file system code and take the write lock, causing
> deadlocks.
> 
> This patch introduces some more helpers and uses them for quota call
> sites.  Without this patch applied, reiserfs + quotas runs into deadlocks
> under anything more than trivial load.
  This patch looks good so I'll merge it once the comment to 2/3 is sorted
out.

								Honza
> 
> Signed-off-by: Jeff Mahoney <jeffm@suse.com>
> ---
> 
>  fs/reiserfs/bitmap.c |   17 +++++++++++++++--
>  fs/reiserfs/inode.c  |   19 +++++++++++--------
>  fs/reiserfs/stree.c  |   28 +++++++++++++++++++++++-----
>  fs/reiserfs/super.c  |   22 ++++++++++++++--------
>  4 files changed, 63 insertions(+), 23 deletions(-)
> 
> --- a/fs/reiserfs/bitmap.c	2013-08-07 10:23:33.885587547 -0400
> +++ b/fs/reiserfs/bitmap.c	2013-08-07 10:23:35.761559089 -0400
> @@ -423,8 +423,11 @@ static void _reiserfs_free_block(struct
>  	set_sb_free_blocks(rs, sb_free_blocks(rs) + 1);
>  
>  	journal_mark_dirty(th, s, sbh);
> -	if (for_unformatted)
> +	if (for_unformatted) {
> +		int depth = reiserfs_write_unlock_nested(s);
>  		dquot_free_block_nodirty(inode, 1);
> +		reiserfs_write_lock_nested(s, depth);
> +	}
>  }
>  
>  void reiserfs_free_block(struct reiserfs_transaction_handle *th,
> @@ -1128,6 +1131,7 @@ static inline int blocknrs_and_prealloc_
>  	b_blocknr_t finish = SB_BLOCK_COUNT(s) - 1;
>  	int passno = 0;
>  	int nr_allocated = 0;
> +	int depth;
>  
>  	determine_prealloc_size(hint);
>  	if (!hint->formatted_node) {
> @@ -1137,10 +1141,13 @@ static inline int blocknrs_and_prealloc_
>  			       "reiserquota: allocating %d blocks id=%u",
>  			       amount_needed, hint->inode->i_uid);
>  #endif
> +		depth = reiserfs_write_unlock_nested(s);
>  		quota_ret =
>  		    dquot_alloc_block_nodirty(hint->inode, amount_needed);
> -		if (quota_ret)	/* Quota exceeded? */
> +		if (quota_ret) {	/* Quota exceeded? */
> +			reiserfs_write_lock_nested(s, depth);
>  			return QUOTA_EXCEEDED;
> +		}
>  		if (hint->preallocate && hint->prealloc_size) {
>  #ifdef REISERQUOTA_DEBUG
>  			reiserfs_debug(s, REISERFS_DEBUG_CODE,
> @@ -1153,6 +1160,7 @@ static inline int blocknrs_and_prealloc_
>  				hint->preallocate = hint->prealloc_size = 0;
>  		}
>  		/* for unformatted nodes, force large allocations */
> +		reiserfs_write_lock_nested(s, depth);
>  	}
>  
>  	do {
> @@ -1181,9 +1189,11 @@ static inline int blocknrs_and_prealloc_
>  					       hint->inode->i_uid);
>  #endif
>  				/* Free not allocated blocks */
> +				depth = reiserfs_write_unlock_nested(s);
>  				dquot_free_block_nodirty(hint->inode,
>  					amount_needed + hint->prealloc_size -
>  					nr_allocated);
> +				reiserfs_write_lock_nested(s, depth);
>  			}
>  			while (nr_allocated--)
>  				reiserfs_free_block(hint->th, hint->inode,
> @@ -1214,10 +1224,13 @@ static inline int blocknrs_and_prealloc_
>  			       REISERFS_I(hint->inode)->i_prealloc_count,
>  			       hint->inode->i_uid);
>  #endif
> +
> +		depth = reiserfs_write_unlock_nested(s);
>  		dquot_free_block_nodirty(hint->inode, amount_needed +
>  					 hint->prealloc_size - nr_allocated -
>  					 REISERFS_I(hint->inode)->
>  					 i_prealloc_count);
> +		reiserfs_write_lock_nested(s, depth);
>  	}
>  
>  	return CARRY_ON;
> --- a/fs/reiserfs/inode.c	2013-08-07 10:23:33.933586826 -0400
> +++ b/fs/reiserfs/inode.c	2013-08-07 10:23:35.781558786 -0400
> @@ -57,8 +57,11 @@ void reiserfs_evict_inode(struct inode *
>  		/* Do quota update inside a transaction for journaled quotas. We must do that
>  		 * after delete_object so that quota updates go into the same transaction as
>  		 * stat data deletion */
> -		if (!err) 
> +		if (!err) {
> +			int depth = reiserfs_write_unlock_nested(inode->i_sb);
>  			dquot_free_inode(inode);
> +			reiserfs_write_lock_nested(inode->i_sb, depth);
> +		}
>  
>  		if (journal_end(&th, inode->i_sb, jbegin_count))
>  			goto out;
> @@ -1768,7 +1771,7 @@ int reiserfs_new_inode(struct reiserfs_t
>  		       struct inode *inode,
>  		       struct reiserfs_security_handle *security)
>  {
> -	struct super_block *sb;
> +	struct super_block *sb = dir->i_sb;
>  	struct reiserfs_iget_args args;
>  	INITIALIZE_PATH(path_to_key);
>  	struct cpu_key key;
> @@ -1780,9 +1783,9 @@ int reiserfs_new_inode(struct reiserfs_t
>  
>  	BUG_ON(!th->t_trans_id);
>  
> -	reiserfs_write_unlock(inode->i_sb);
> +	depth = reiserfs_write_unlock_nested(sb);
>  	err = dquot_alloc_inode(inode);
> -	reiserfs_write_lock(inode->i_sb);
> +	reiserfs_write_lock_nested(sb, depth);
>  	if (err)
>  		goto out_end_trans;
>  	if (!dir->i_nlink) {
> @@ -1790,8 +1793,6 @@ int reiserfs_new_inode(struct reiserfs_t
>  		goto out_bad_inode;
>  	}
>  
> -	sb = dir->i_sb;
> -
>  	/* item head of new item */
>  	ih.ih_key.k_dir_id = reiserfs_choose_packing(dir);
>  	ih.ih_key.k_objectid = cpu_to_le32(reiserfs_get_unused_objectid(th));
> @@ -1983,14 +1984,16 @@ int reiserfs_new_inode(struct reiserfs_t
>  	INODE_PKEY(inode)->k_objectid = 0;
>  
>  	/* Quota change must be inside a transaction for journaling */
> +	depth = reiserfs_write_unlock_nested(inode->i_sb);
>  	dquot_free_inode(inode);
> +	reiserfs_write_lock_nested(inode->i_sb, depth);
>  
>        out_end_trans:
>  	journal_end(th, th->t_super, th->t_blocks_allocated);
> -	reiserfs_write_unlock(inode->i_sb);
>  	/* Drop can be outside and it needs more credits so it's better to have it outside */
> +	depth = reiserfs_write_unlock_nested(inode->i_sb);
>  	dquot_drop(inode);
> -	reiserfs_write_lock(inode->i_sb);
> +	reiserfs_write_lock_nested(inode->i_sb, depth);
>  	inode->i_flags |= S_NOQUOTA;
>  	make_bad_inode(inode);
>  
> --- a/fs/reiserfs/stree.c	2013-08-07 10:23:34.037585247 -0400
> +++ b/fs/reiserfs/stree.c	2013-08-07 10:23:35.793558603 -0400
> @@ -1190,6 +1190,7 @@ int reiserfs_delete_item(struct reiserfs
>  	struct item_head *q_ih;
>  	int quota_cut_bytes;
>  	int ret_value, del_size, removed;
> +	int depth;
>  
>  #ifdef CONFIG_REISERFS_CHECK
>  	char mode;
> @@ -1299,7 +1300,9 @@ int reiserfs_delete_item(struct reiserfs
>  		       "reiserquota delete_item(): freeing %u, id=%u type=%c",
>  		       quota_cut_bytes, inode->i_uid, head2type(&s_ih));
>  #endif
> +	depth = reiserfs_write_unlock_nested(inode->i_sb);
>  	dquot_free_space_nodirty(inode, quota_cut_bytes);
> +	reiserfs_write_lock_nested(inode->i_sb, depth);
>  
>  	/* Return deleted body length */
>  	return ret_value;
> @@ -1325,6 +1328,7 @@ int reiserfs_delete_item(struct reiserfs
>  void reiserfs_delete_solid_item(struct reiserfs_transaction_handle *th,
>  				struct inode *inode, struct reiserfs_key *key)
>  {
> +	struct super_block *sb = th->t_super;
>  	struct tree_balance tb;
>  	INITIALIZE_PATH(path);
>  	int item_len = 0;
> @@ -1377,14 +1381,17 @@ void reiserfs_delete_solid_item(struct r
>  		if (retval == CARRY_ON) {
>  			do_balance(&tb, NULL, NULL, M_DELETE);
>  			if (inode) {	/* Should we count quota for item? (we don't count quotas for save-links) */
> +				int depth;
>  #ifdef REISERQUOTA_DEBUG
>  				reiserfs_debug(th->t_super, REISERFS_DEBUG_CODE,
>  					       "reiserquota delete_solid_item(): freeing %u id=%u type=%c",
>  					       quota_cut_bytes, inode->i_uid,
>  					       key2type(key));
>  #endif
> +				depth = reiserfs_write_unlock_nested(sb);
>  				dquot_free_space_nodirty(inode,
>  							 quota_cut_bytes);
> +				reiserfs_write_lock_nested(sb, depth);
>  			}
>  			break;
>  		}
> @@ -1561,6 +1568,7 @@ int reiserfs_cut_from_item(struct reiser
>  	int retval2 = -1;
>  	int quota_cut_bytes;
>  	loff_t tail_pos = 0;
> +	int depth;
>  
>  	BUG_ON(!th->t_trans_id);
>  
> @@ -1733,7 +1741,9 @@ int reiserfs_cut_from_item(struct reiser
>  		       "reiserquota cut_from_item(): freeing %u id=%u type=%c",
>  		       quota_cut_bytes, inode->i_uid, '?');
>  #endif
> +	depth = reiserfs_write_unlock_nested(sb);
>  	dquot_free_space_nodirty(inode, quota_cut_bytes);
> +	reiserfs_write_lock_nested(sb, depth);
>  	return ret_value;
>  }
>  
> @@ -1953,9 +1963,11 @@ int reiserfs_paste_into_item(struct reis
>  			     const char *body,	/* Pointer to the bytes to paste.    */
>  			     int pasted_size)
>  {				/* Size of pasted bytes.             */
> +	struct super_block *sb = inode->i_sb;
>  	struct tree_balance s_paste_balance;
>  	int retval;
>  	int fs_gen;
> +	int depth;
>  
>  	BUG_ON(!th->t_trans_id);
>  
> @@ -1968,9 +1980,9 @@ int reiserfs_paste_into_item(struct reis
>  		       key2type(&(key->on_disk_key)));
>  #endif
>  
> -	reiserfs_write_unlock(inode->i_sb);
> +	depth = reiserfs_write_unlock_nested(sb);
>  	retval = dquot_alloc_space_nodirty(inode, pasted_size);
> -	reiserfs_write_lock(inode->i_sb);
> +	reiserfs_write_lock_nested(sb, depth);
>  	if (retval) {
>  		pathrelse(search_path);
>  		return retval;
> @@ -2027,7 +2039,9 @@ int reiserfs_paste_into_item(struct reis
>  		       pasted_size, inode->i_uid,
>  		       key2type(&(key->on_disk_key)));
>  #endif
> +	depth = reiserfs_write_unlock_nested(sb);
>  	dquot_free_space_nodirty(inode, pasted_size);
> +	reiserfs_write_lock_nested(sb, depth);
>  	return retval;
>  }
>  
> @@ -2050,6 +2064,7 @@ int reiserfs_insert_item(struct reiserfs
>  	BUG_ON(!th->t_trans_id);
>  
>  	if (inode) {		/* Do we count quotas for item? */
> +		int depth;
>  		fs_gen = get_generation(inode->i_sb);
>  		quota_bytes = ih_item_len(ih);
>  
> @@ -2063,11 +2078,11 @@ int reiserfs_insert_item(struct reiserfs
>  			       "reiserquota insert_item(): allocating %u id=%u type=%c",
>  			       quota_bytes, inode->i_uid, head2type(ih));
>  #endif
> -		reiserfs_write_unlock(inode->i_sb);
>  		/* We can't dirty inode here. It would be immediately written but
>  		 * appropriate stat item isn't inserted yet... */
> +		depth = reiserfs_write_unlock_nested(inode->i_sb);
>  		retval = dquot_alloc_space_nodirty(inode, quota_bytes);
> -		reiserfs_write_lock(inode->i_sb);
> +		reiserfs_write_lock_nested(inode->i_sb, depth);
>  		if (retval) {
>  			pathrelse(path);
>  			return retval;
> @@ -2118,7 +2133,10 @@ int reiserfs_insert_item(struct reiserfs
>  		       "reiserquota insert_item(): freeing %u id=%u type=%c",
>  		       quota_bytes, inode->i_uid, head2type(ih));
>  #endif
> -	if (inode)
> +	if (inode) {
> +		int depth = reiserfs_write_unlock_nested(inode->i_sb);
>  		dquot_free_space_nodirty(inode, quota_bytes);
> +		reiserfs_write_lock_nested(inode->i_sb, depth);
> +	}
>  	return retval;
>  }
> --- a/fs/reiserfs/super.c	2013-08-07 10:23:34.049585066 -0400
> +++ b/fs/reiserfs/super.c	2013-08-07 10:23:35.805558422 -0400
> @@ -243,6 +243,7 @@ static int finish_unfinished(struct supe
>  	done = 0;
>  	REISERFS_SB(s)->s_is_unlinked_ok = 1;
>  	while (!retval) {
> +		int depth;
>  		retval = search_item(s, &max_cpu_key, &path);
>  		if (retval != ITEM_NOT_FOUND) {
>  			reiserfs_error(s, "vs-2140",
> @@ -298,9 +299,9 @@ static int finish_unfinished(struct supe
>  			retval = remove_save_link_only(s, &save_link_key, 0);
>  			continue;
>  		}
> -		reiserfs_write_unlock(s);
> +		depth = reiserfs_write_unlock_nested(inode->i_sb);
>  		dquot_initialize(inode);
> -		reiserfs_write_lock(s);
> +		reiserfs_write_lock_nested(inode->i_sb, depth);
>  
>  		if (truncate && S_ISDIR(inode->i_mode)) {
>  			/* We got a truncate request for a dir which is impossible.
> @@ -356,10 +357,12 @@ static int finish_unfinished(struct supe
>  
>  #ifdef CONFIG_QUOTA
>  	/* Turn quotas off */
> +	reiserfs_write_unlock(s);
>  	for (i = 0; i < MAXQUOTAS; i++) {
>  		if (sb_dqopt(s)->files[i] && quota_enabled[i])
>  			dquot_quota_off(s, i);
>  	}
> +	reiserfs_write_lock(s);
>  	if (ms_active_set)
>  		/* Restore the flag back */
>  		s->s_flags &= ~MS_ACTIVE;
> @@ -2098,6 +2101,7 @@ static int reiserfs_write_dquot(struct d
>  {
>  	struct reiserfs_transaction_handle th;
>  	int ret, err;
> +	int depth;
>  
>  	reiserfs_write_lock(dquot->dq_sb);
>  	ret =
> @@ -2105,9 +2109,9 @@ static int reiserfs_write_dquot(struct d
>  			  REISERFS_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
>  	if (ret)
>  		goto out;
> -	reiserfs_write_unlock(dquot->dq_sb);
> +	depth = reiserfs_write_unlock_nested(dquot->dq_sb);
>  	ret = dquot_commit(dquot);
> -	reiserfs_write_lock(dquot->dq_sb);
> +	reiserfs_write_lock_nested(dquot->dq_sb, depth);
>  	err =
>  	    journal_end(&th, dquot->dq_sb,
>  			REISERFS_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
> @@ -2122,6 +2126,7 @@ static int reiserfs_acquire_dquot(struct
>  {
>  	struct reiserfs_transaction_handle th;
>  	int ret, err;
> +	int depth;
>  
>  	reiserfs_write_lock(dquot->dq_sb);
>  	ret =
> @@ -2129,9 +2134,9 @@ static int reiserfs_acquire_dquot(struct
>  			  REISERFS_QUOTA_INIT_BLOCKS(dquot->dq_sb));
>  	if (ret)
>  		goto out;
> -	reiserfs_write_unlock(dquot->dq_sb);
> +	depth = reiserfs_write_unlock_nested(dquot->dq_sb);
>  	ret = dquot_acquire(dquot);
> -	reiserfs_write_lock(dquot->dq_sb);
> +	reiserfs_write_lock_nested(dquot->dq_sb, depth);
>  	err =
>  	    journal_end(&th, dquot->dq_sb,
>  			REISERFS_QUOTA_INIT_BLOCKS(dquot->dq_sb));
> @@ -2184,15 +2189,16 @@ static int reiserfs_write_info(struct su
>  {
>  	struct reiserfs_transaction_handle th;
>  	int ret, err;
> +	int depth;
>  
>  	/* Data block + inode block */
>  	reiserfs_write_lock(sb);
>  	ret = journal_begin(&th, sb, 2);
>  	if (ret)
>  		goto out;
> -	reiserfs_write_unlock(sb);
> +	depth = reiserfs_write_unlock_nested(sb);
>  	ret = dquot_commit_info(sb, type);
> -	reiserfs_write_lock(sb);
> +	reiserfs_write_lock_nested(sb, depth);
>  	err = journal_end(&th, sb, 2);
>  	if (!ret && err)
>  		ret = err;
> 
> 
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR