introduce I_SYNC

I_LOCK was used for several unrelated purposes, which caused deadlock
situations in certain filesystems as a side effect.  One of the purposes
now uses the new I_SYNC bit.

Also document the various bits and change their order from historical to
logical.

[bunk@stusta.de: make fs/inode.c:wake_up_inode() static]
Signed-off-by: Joern Engel <joern@wohnheim.fh-wedel.de>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Anton Altaparmakov <aia21@cam.ac.uk>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 12 deletions

diff --git a/fs/inode.c b/fs/inode.c
index c6165771e00e..ed35383d0b6c 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -99,6 +99,15 @@ struct inodes_stat_t inodes_stat;
 
 static struct kmem_cache * inode_cachep __read_mostly;
 
+static void wake_up_inode(struct inode *inode)
+{
+        /*
+         * Prevent speculative execution through spin_unlock(&inode_lock);
+         */
+        smp_mb();
+        wake_up_bit(&inode->i_state, __I_LOCK);
+}
+
 static struct inode *alloc_inode(struct super_block *sb)
 {
         static const struct address_space_operations empty_aops;
@@ -232,7 +241,7 @@ void __iget(struct inode * inode)
                 return;
         }
         atomic_inc(&inode->i_count);
-        if (!(inode->i_state & (I_DIRTY|I_LOCK)))
+        if (!(inode->i_state & (I_DIRTY|I_SYNC)))
                 list_move(&inode->i_list, &inode_in_use);
         inodes_stat.nr_unused--;
 }
@@ -253,7 +262,7 @@ void clear_inode(struct inode *inode)
         BUG_ON(inode->i_data.nrpages);
         BUG_ON(!(inode->i_state & I_FREEING));
         BUG_ON(inode->i_state & I_CLEAR);
-        wait_on_inode(inode);
+        inode_sync_wait(inode);
         DQUOT_DROP(inode);
         if (inode->i_sb->s_op->clear_inode)
                 inode->i_sb->s_op->clear_inode(inode);
@@ -1071,7 +1080,7 @@ static void generic_forget_inode(struct inode *inode)
         struct super_block *sb = inode->i_sb;
 
         if (!hlist_unhashed(&inode->i_hash)) {
-                if (!(inode->i_state & (I_DIRTY|I_LOCK)))
+                if (!(inode->i_state & (I_DIRTY|I_SYNC)))
                         list_move(&inode->i_list, &inode_unused);
                 inodes_stat.nr_unused++;
                 if (sb->s_flags & MS_ACTIVE) {
@@ -1314,15 +1323,6 @@ static void __wait_on_freeing_inode(struct inode *inode)
         spin_lock(&inode_lock);
 }
 
-void wake_up_inode(struct inode *inode)
-{
-        /*
-         * Prevent speculative execution through spin_unlock(&inode_lock);
-         */
-        smp_mb();
-        wake_up_bit(&inode->i_state, __I_LOCK);
-}
-
 /*
  * We rarely want to lock two inodes that do not have a parent/child
  * relationship (such as directory, child inode) simultaneously. The