truncate: use new helpers

Update some fs code to make use of new helper functions introduced
in the previous patch. Should be no significant change in behaviour
(except CIFS now calls send_sig under i_lock, via inode_newsize_ok).

Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: linux-nfs@vger.kernel.org
Cc: Trond.Myklebust@netapp.com
Cc: linux-cifs-client@lists.samba.org
Cc: sfrench@samba.org
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 13 insertions, 41 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 060022b4651c..faa091865ad0 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -458,49 +458,21 @@ nfs_setattr(struct dentry *dentry, struct iattr *attr)
  */
 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
 {
-        if (i_size_read(inode) < offset) {
-                unsigned long limit;
-
-                limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
-                if (limit != RLIM_INFINITY && offset > limit)
-                        goto out_sig;
-                if (offset > inode->i_sb->s_maxbytes)
-                        goto out_big;
-                spin_lock(&inode->i_lock);
-                i_size_write(inode, offset);
-                spin_unlock(&inode->i_lock);
-        } else {
-                struct address_space *mapping = inode->i_mapping;
+        loff_t oldsize;
+        int err;
 
-                /*
-                 * truncation of in-use swapfiles is disallowed - it would
-                 * cause subsequent swapout to scribble on the now-freed
-                 * blocks.
-                 */
-                if (IS_SWAPFILE(inode))
-                        return -ETXTBSY;
-                spin_lock(&inode->i_lock);
-                i_size_write(inode, offset);
-                spin_unlock(&inode->i_lock);
+        err = inode_newsize_ok(inode, offset);
+        if (err)
+                goto out;
 
-                /*
-                 * unmap_mapping_range is called twice, first simply for
-                 * efficiency so that truncate_inode_pages does fewer
-                 * single-page unmaps.  However after this first call, and
-                 * before truncate_inode_pages finishes, it is possible for
-                 * private pages to be COWed, which remain after
-                 * truncate_inode_pages finishes, hence the second
-                 * unmap_mapping_range call must be made for correctness.
-                 */
-                unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
-                truncate_inode_pages(mapping, offset);
-                unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
-        }
-        return 0;
-out_sig:
-        send_sig(SIGXFSZ, current, 0);
-out_big:
-        return -EFBIG;
+        spin_lock(&inode->i_lock);
+        oldsize = inode->i_size;
+        i_size_write(inode, offset);
+        spin_unlock(&inode->i_lock);
+
+        truncate_pagecache(inode, oldsize, offset);
+out:
+        return err;
 }
 
 /**