[PATCH] affs: implement ->drop_inode

affs wants to truncate the inode when the last user goes away, currently it
does that through a potentially racy i_count check in ->put_inode.  But we
already have a method that's called just after the we dropped the last
reference, ->drop_inode.  This patch implements affs_drop_inode to take
advantage of this.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 13 insertions, 6 deletions

diff --git a/fs/affs/affs.h b/fs/affs/affs.h
index 7db2d287e9f3..232c69493683 100644
--- a/fs/affs/affs.h
+++ b/fs/affs/affs.h
@@ -171,6 +171,7 @@ extern unsigned long		 affs_parent_ino(struct inode *dir);
 extern struct inode             *affs_new_inode(struct inode *dir);
 extern int                       affs_notify_change(struct dentry *dentry, struct iattr *attr);
 extern void                      affs_put_inode(struct inode *inode);
+extern void                      affs_drop_inode(struct inode *inode);
 extern void                      affs_delete_inode(struct inode *inode);
 extern void                      affs_clear_inode(struct inode *inode);
 extern void                      affs_read_inode(struct inode *inode);
diff --git a/fs/affs/inode.c b/fs/affs/inode.c
index fce6848a4641..c5b9d73c084a 100644
--- a/fs/affs/inode.c
+++ b/fs/affs/inode.c
@@ -243,12 +243,17 @@ affs_put_inode(struct inode *inode)
 {
         pr_debug("AFFS: put_inode(ino=%lu, nlink=%u)\n", inode->i_ino, inode->i_nlink);
         affs_free_prealloc(inode);
-        if (atomic_read(&inode->i_count) == 1) {
-                mutex_lock(&inode->i_mutex);
-                if (inode->i_size != AFFS_I(inode)->mmu_private)
-                        affs_truncate(inode);
-                mutex_unlock(&inode->i_mutex);
-        }
+}
+
+void
+affs_drop_inode(struct inode *inode)
+{
+        mutex_lock(&inode->i_mutex);
+        if (inode->i_size != AFFS_I(inode)->mmu_private)
+                affs_truncate(inode);
+        mutex_unlock(&inode->i_mutex);
+
+        generic_drop_inode(inode);
 }
 
 void
diff --git a/fs/affs/super.c b/fs/affs/super.c
index a324045d8554..c3986a1911b0 100644
--- a/fs/affs/super.c
+++ b/fs/affs/super.c
@@ -118,6 +118,7 @@ static const struct super_operations affs_sops = {
         .read_inode     = affs_read_inode,
         .write_inode    = affs_write_inode,
         .put_inode      = affs_put_inode,
+        .drop_inode     = affs_drop_inode,
         .delete_inode   = affs_delete_inode,
         .clear_inode    = affs_clear_inode,
         .put_super      = affs_put_super,