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, 10 insertions, 43 deletions

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 1f09c7619319..5e2492535daa 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1557,57 +1557,24 @@ static int cifs_truncate_page(struct address_space *mapping, loff_t from)
 
 static int cifs_vmtruncate(struct inode *inode, loff_t offset)
 {
-        struct address_space *mapping = inode->i_mapping;
-        unsigned long limit;
+        loff_t oldsize;
+        int err;
 
         spin_lock(&inode->i_lock);
-        if (inode->i_size < offset)
-                goto do_expand;
-        /*
-         * truncation of in-use swapfiles is disallowed - it would cause
-         * subsequent swapout to scribble on the now-freed blocks.
-         */
-        if (IS_SWAPFILE(inode)) {
-                spin_unlock(&inode->i_lock);
-                goto out_busy;
-        }
-        i_size_write(inode, offset);
-        spin_unlock(&inode->i_lock);
-        /*
-         * 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);
-        goto out_truncate;
-
-do_expand:
-        limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
-        if (limit != RLIM_INFINITY && offset > limit) {
+        err = inode_newsize_ok(inode, offset);
+        if (err) {
                 spin_unlock(&inode->i_lock);
-                goto out_sig;
-        }
-        if (offset > inode->i_sb->s_maxbytes) {
-                spin_unlock(&inode->i_lock);
-                goto out_big;
+                goto out;
         }
+
+        oldsize = inode->i_size;
         i_size_write(inode, offset);
         spin_unlock(&inode->i_lock);
-out_truncate:
+        truncate_pagecache(inode, oldsize, offset);
         if (inode->i_op->truncate)
                 inode->i_op->truncate(inode);
-        return 0;
-out_sig:
-        send_sig(SIGXFSZ, current, 0);
-out_big:
-        return -EFBIG;
-out_busy:
-        return -ETXTBSY;
+out:
+        return err;
 }
 
 static int