reiserfs: journaled xattrs

Deadlocks are possible in the xattr code between the journal lock and the
xattr sems.

This patch implements journalling for xattr operations. The benefit is
twofold:
 * It gets rid of the deadlock possibility by always ensuring that xattr
   write operations are initiated inside a transaction.
 * It corrects the problem where xattr backing files aren't considered any
   differently than normal files, despite the fact they are metadata.

I discussed the added journal load with Chris Mason, and we decided that
since xattrs (versus other journal activity) is fairly rare, the introduction
of larger transactions to support journaled xattrs wouldn't be too big a deal.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 11 deletions

diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index ddf1bcd..d9c1c8b 100644
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -598,15 +598,13 @@ static int reiserfs_create(struct inode *dir, struct dentry *dentry, int mode,
 	    2 * (REISERFS_QUOTA_INIT_BLOCKS(dir->i_sb) +
 		 REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb));
 	struct reiserfs_transaction_handle th;
-	int locked;
 
 	if (!(inode = new_inode(dir->i_sb))) {
 		return -ENOMEM;
 	}
 	new_inode_init(inode, dir, mode);
 
-	locked = reiserfs_cache_default_acl(dir);
-
+	jbegin_count += reiserfs_cache_default_acl(dir);
 	reiserfs_write_lock(dir->i_sb);
 
 	retval = journal_begin(&th, dir->i_sb, jbegin_count);
@@ -662,7 +660,6 @@ static int reiserfs_mknod(struct inode *dir, struct dentry *dentry, int mode,
 	    JOURNAL_PER_BALANCE_CNT * 3 +
 	    2 * (REISERFS_QUOTA_INIT_BLOCKS(dir->i_sb) +
 		 REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb));
-	int locked;
 
 	if (!new_valid_dev(rdev))
 		return -EINVAL;
@@ -672,8 +669,7 @@ static int reiserfs_mknod(struct inode *dir, struct dentry *dentry, int mode,
 	}
 	new_inode_init(inode, dir, mode);
 
-	locked = reiserfs_cache_default_acl(dir);
-
+	jbegin_count += reiserfs_cache_default_acl(dir);
 	reiserfs_write_lock(dir->i_sb);
 
 	retval = journal_begin(&th, dir->i_sb, jbegin_count);
@@ -732,7 +728,6 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 	    JOURNAL_PER_BALANCE_CNT * 3 +
 	    2 * (REISERFS_QUOTA_INIT_BLOCKS(dir->i_sb) +
 		 REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb));
-	int locked;
 
 #ifdef DISPLACE_NEW_PACKING_LOCALITIES
 	/* set flag that new packing locality created and new blocks for the content     * of that directory are not displaced yet */
@@ -744,8 +739,7 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 	}
 	new_inode_init(inode, dir, mode);
 
-	locked = reiserfs_cache_default_acl(dir);
-
+	jbegin_count += reiserfs_cache_default_acl(dir);
 	reiserfs_write_lock(dir->i_sb);
 
 	retval = journal_begin(&th, dir->i_sb, jbegin_count);
@@ -1034,8 +1028,6 @@ static int reiserfs_symlink(struct inode *parent_dir,
 	memcpy(name, symname, strlen(symname));
 	padd_item(name, item_len, strlen(symname));
 
-	/* We would inherit the default ACL here, but symlinks don't get ACLs */
-
 	retval = journal_begin(&th, parent_dir->i_sb, jbegin_count);
 	if (retval) {
 		drop_new_inode(inode);