diff options
| author | Stephen Warren <swarren@nvidia.com> | 2014-06-11 12:46:16 -0600 |
|---|---|---|
| committer | Tom Rini <trini@ti.com> | 2014-06-19 11:18:53 -0400 |
| commit | d018028055a21a28adef16b7f95422c426b46d60 (patch) | |
| tree | 24546aa499a82610c0af24849a6239fc7cd09130 /fs | |
| parent | 50babaf852e3b48680f7ea782a756043f64f8fe2 (diff) | |
fs: ext4: fix writing zero-length files
ext4fs_allocate_blocks() always allocates at least one block for a file.
If the file size is zero, this causes total_remaining_blocks to
underflow, which then causes an apparent hang while 2^32 blocks are
allocated.
To solve this, check that total_remaining_blocks is non-zero as part of
the loop condition (i.e. before each loop) rather than at the end of
the loop.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/ext4_common.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c index 1c1172163c0..33d69c9c71f 100644 --- a/fs/ext4/ext4_common.c +++ b/fs/ext4/ext4_common.c @@ -1380,7 +1380,7 @@ void ext4fs_allocate_blocks(struct ext2_inode *file_inode, unsigned int no_blks_reqd = 0; /* allocation of direct blocks */ - for (i = 0; i < INDIRECT_BLOCKS; i++) { + for (i = 0; total_remaining_blocks && i < INDIRECT_BLOCKS; i++) { direct_blockno = ext4fs_get_new_blk_no(); if (direct_blockno == -1) { printf("no block left to assign\n"); @@ -1390,8 +1390,6 @@ void ext4fs_allocate_blocks(struct ext2_inode *file_inode, debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks); total_remaining_blocks--; - if (total_remaining_blocks == 0) - break; } alloc_single_indirect_block(file_inode, &total_remaining_blocks, |