vfs: split generic_forget_inode() so that hugetlbfs does not have to copy it

Hugetlbfs needs to do special things instead of truncate_inode_pages().
 Currently, it copied generic_forget_inode() except for
truncate_inode_pages() call which is asking for trouble (the code there
isn't trivial).  So create a separate function generic_detach_inode()
which does all the list magic done in generic_forget_inode() and call
it from hugetlbfs_forget_inode().

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index eba6d55..478a169 100644 (file)
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -380,36 +380,11 @@ static void hugetlbfs_delete_inode(struct inode *inode)
 
 static void hugetlbfs_forget_inode(struct inode *inode) __releases(inode_lock)
 {
-       struct super_block *sb = inode->i_sb;
-
-       if (!hlist_unhashed(&inode->i_hash)) {
-               if (!(inode->i_state & (I_DIRTY|I_SYNC)))
-                       list_move(&inode->i_list, &inode_unused);
-               inodes_stat.nr_unused++;
-               if (!sb || (sb->s_flags & MS_ACTIVE)) {
-                       spin_unlock(&inode_lock);
-                       return;
-               }
-               inode->i_state |= I_WILL_FREE;
-               spin_unlock(&inode_lock);
-               /*
-                * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK
-                * in our backing_dev_info.
-                */
-               write_inode_now(inode, 1);
-               spin_lock(&inode_lock);
-               inode->i_state &= ~I_WILL_FREE;
-               inodes_stat.nr_unused--;
-               hlist_del_init(&inode->i_hash);
+       if (generic_detach_inode(inode)) {
+               truncate_hugepages(inode, 0);
+               clear_inode(inode);
+               destroy_inode(inode);
        }
-       list_del_init(&inode->i_list);
-       list_del_init(&inode->i_sb_list);
-       inode->i_state |= I_FREEING;
-       inodes_stat.nr_inodes--;
-       spin_unlock(&inode_lock);
-       truncate_hugepages(inode, 0);
-       clear_inode(inode);
-       destroy_inode(inode);
 }
 
 static void hugetlbfs_drop_inode(struct inode *inode)

diff --git a/fs/inode.c b/fs/inode.c
index 07d775e..fa506d5 100644 (file)
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1241,7 +1241,16 @@ void generic_delete_inode(struct inode *inode)
 }
 EXPORT_SYMBOL(generic_delete_inode);
 
-static void generic_forget_inode(struct inode *inode)
+/**
+ *     generic_detach_inode - remove inode from inode lists
+ *     @inode: inode to remove
+ *
+ *     Remove inode from inode lists, write it if it's dirty. This is just an
+ *     internal VFS helper exported for hugetlbfs. Do not use!
+ *
+ *     Returns 1 if inode should be completely destroyed.
+ */
+int generic_detach_inode(struct inode *inode)
 {
        struct super_block *sb = inode->i_sb;
 
@@ -1251,7 +1260,7 @@ static void generic_forget_inode(struct inode *inode)
                inodes_stat.nr_unused++;
                if (sb->s_flags & MS_ACTIVE) {
                        spin_unlock(&inode_lock);
-                       return;
+                       return 0;
                }
                WARN_ON(inode->i_state & I_NEW);
                inode->i_state |= I_WILL_FREE;
@@ -1269,6 +1278,14 @@ static void generic_forget_inode(struct inode *inode)
        inode->i_state |= I_FREEING;
        inodes_stat.nr_inodes--;
        spin_unlock(&inode_lock);
+       return 1;
+}
+EXPORT_SYMBOL_GPL(generic_detach_inode);
+
+static void generic_forget_inode(struct inode *inode)
+{
+       if (!generic_detach_inode(inode))
+               return;
        if (inode->i_data.nrpages)
                truncate_inode_pages(&inode->i_data, 0);
        clear_inode(inode);

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 5180352..955e346 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2156,6 +2156,7 @@ extern ino_t iunique(struct super_block *, ino_t);
 extern int inode_needs_sync(struct inode *inode);
 extern void generic_delete_inode(struct inode *inode);
 extern void generic_drop_inode(struct inode *inode);
+extern int generic_detach_inode(struct inode *inode);
 
 extern struct inode *ilookup5_nowait(struct super_block *sb,
                unsigned long hashval, int (*test)(struct inode *, void *),