ext4: prevent ext4_quota_write() from failing due to ENOSPC

[mirror_ubuntu-artful-kernel.git] / fs / ext4 / inode.c

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 55b187c3bac1f1626cf0267734aa805b6f9a1263..e8a67b8ba90c39712712c47a124fa5a721e29a46 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -731,18 +731,18 @@ int ext4_get_block(struct inode *inode, sector_t iblock,
  * `handle' can be NULL if create is zero
  */
 struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
-                               ext4_lblk_t block, int create)
+                               ext4_lblk_t block, int map_flags)
 {
        struct ext4_map_blocks map;
        struct buffer_head *bh;
+       int create = map_flags & EXT4_GET_BLOCKS_CREATE;
        int err;
 
        J_ASSERT(handle != NULL || create == 0);
 
        map.m_lblk = block;
        map.m_len = 1;
-       err = ext4_map_blocks(handle, inode, &map,
-                             create ? EXT4_GET_BLOCKS_CREATE : 0);
+       err = ext4_map_blocks(handle, inode, &map, map_flags);
 
        if (err == 0)
                return create ? ERR_PTR(-ENOSPC) : NULL;
@@ -788,11 +788,11 @@ errout:
 }
 
 struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
-                              ext4_lblk_t block, int create)
+                              ext4_lblk_t block, int map_flags)
 {
        struct buffer_head *bh;
 
-       bh = ext4_getblk(handle, inode, block, create);
+       bh = ext4_getblk(handle, inode, block, map_flags);
        if (IS_ERR(bh))
                return bh;
        if (!bh || buffer_uptodate(bh))
@@ -1701,19 +1701,32 @@ static int __ext4_journalled_writepage(struct page *page,
                ext4_walk_page_buffers(handle, page_bufs, 0, len,
                                       NULL, bget_one);
        }
-       /* As soon as we unlock the page, it can go away, but we have
-        * references to buffers so we are safe */
+       /*
+        * We need to release the page lock before we start the
+        * journal, so grab a reference so the page won't disappear
+        * out from under us.
+        */
+       get_page(page);
        unlock_page(page);
 
        handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
                                    ext4_writepage_trans_blocks(inode));
        if (IS_ERR(handle)) {
                ret = PTR_ERR(handle);
-               goto out;
+               put_page(page);
+               goto out_no_pagelock;
        }
-
        BUG_ON(!ext4_handle_valid(handle));
 
+       lock_page(page);
+       put_page(page);
+       if (page->mapping != mapping) {
+               /* The page got truncated from under us */
+               ext4_journal_stop(handle);
+               ret = 0;
+               goto out;
+       }
+
        if (inline_data) {
                BUFFER_TRACE(inode_bh, "get write access");
                ret = ext4_journal_get_write_access(handle, inode_bh);
@@ -1739,6 +1752,8 @@ static int __ext4_journalled_writepage(struct page *page,
                                       NULL, bput_one);
        ext4_set_inode_state(inode, EXT4_STATE_JDATA);
 out:
+       unlock_page(page);
+out_no_pagelock:
        brelse(inode_bh);
        return ret;
 }
@@ -4345,7 +4360,7 @@ static void ext4_update_other_inodes_time(struct super_block *sb,
        int inode_size = EXT4_INODE_SIZE(sb);
 
        oi.orig_ino = orig_ino;
-       ino = orig_ino & ~(inodes_per_block - 1);
+       ino = (orig_ino & ~(inodes_per_block - 1)) + 1;
        for (i = 0; i < inodes_per_block; i++, ino++, buf += inode_size) {
                if (ino == orig_ino)
                        continue;