ext4: check for extents that wrap around

[pandora-kernel.git] / fs / ext4 / extents.c

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 834d9a1..bb40a70 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -319,9 +319,13 @@ static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
        ext4_fsblk_t block = ext4_ext_pblock(ext);
        int len = ext4_ext_get_actual_len(ext);
        ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
-       ext4_lblk_t last = lblock + len - 1;
 
-       if (lblock > last)
+       /*
+        * We allow neither:
+        *  - zero length
+        *  - overflow/wrap-around
+        */
+       if (lblock + len <= lblock)
                return 0;
        return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
 }
@@ -700,7 +704,8 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
                path[ppos].p_depth = i;
                path[ppos].p_ext = NULL;
 
-               bh = sb_getblk(inode->i_sb, path[ppos].p_block);
+               bh = sb_getblk_gfp(inode->i_sb, path[ppos].p_block,
+                                  __GFP_MOVABLE | GFP_NOFS);
                if (unlikely(!bh)) {
                        ret = -ENOMEM;
                        goto err;
@@ -905,7 +910,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                err = -EIO;
                goto cleanup;
        }
-       bh = sb_getblk(inode->i_sb, newblock);
+       bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
        if (!bh) {
                err = -ENOMEM;
                goto cleanup;
@@ -1089,7 +1094,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
        if (newblock == 0)
                return err;
 
-       bh = sb_getblk(inode->i_sb, newblock);
+       bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
        if (!bh)
                return -ENOMEM;
        lock_buffer(bh);
@@ -4470,13 +4475,6 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
        struct ext4_map_blocks map;
        unsigned int credits, blkbits = inode->i_blkbits;
 
-       /*
-        * currently supporting (pre)allocate mode for extent-based
-        * files _only_
-        */
-       if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
-               return -EOPNOTSUPP;
-
        /* Return error if mode is not supported */
        if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
                return -EOPNOTSUPP;
@@ -4497,6 +4495,15 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
         */
        credits = ext4_chunk_trans_blocks(inode, max_blocks);
        mutex_lock(&inode->i_mutex);
+
+       /*
+        * We only support preallocation for extent-based files only
+        */
+       if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
+               ret = -EOPNOTSUPP;
+               goto out;
+       }
+
        ret = inode_newsize_ok(inode, (len + offset));
        if (ret) {
                mutex_unlock(&inode->i_mutex);
@@ -4553,6 +4560,7 @@ retry:
                ret = 0;
                goto retry;
        }
+out:
        mutex_unlock(&inode->i_mutex);
        trace_ext4_fallocate_exit(inode, offset, max_blocks,
                                ret > 0 ? ret2 : ret);