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authorChris Mason <chris.mason@oracle.com>2011-06-03 01:26:53 -0400
committerChris Mason <chris.mason@oracle.com>2011-06-04 08:03:43 -0400
commit211f96c24f117fcc6e9e2431e40d92f4de22625e (patch)
tree9f73c5419e905066653660ec33f8d5efeaa3a148
parent17aca1c987cff89dc4279371857035da902c8854 (diff)
downloadlinux-stericsson-211f96c24f117fcc6e9e2431e40d92f4de22625e.tar.gz
Btrfs: make sure we don't overflow the free space cache crc page
The free space cache uses only one page for crcs right now, which means we can't have a cache file bigger than the crcs we can fit in the first page. This adds a check to enforce that restriction. Signed-off-by: Chris Mason <chris.mason@oracle.com>
-rw-r--r--fs/btrfs/free-space-cache.c27
1 files changed, 19 insertions, 8 deletions
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index dd38d4c3a599..1cb72394498c 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -590,10 +590,25 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT;
+
+ /* Since the first page has all of our checksums and our generation we
+ * need to calculate the offset into the page that we can start writing
+ * our entries.
+ */
+ first_page_offset = (sizeof(u32) * num_pages) + sizeof(u64);
+
filemap_write_and_wait(inode->i_mapping);
btrfs_wait_ordered_range(inode, inode->i_size &
~(root->sectorsize - 1), (u64)-1);
+ /* make sure we don't overflow that first page */
+ if (first_page_offset + sizeof(struct btrfs_free_space_entry) >= PAGE_CACHE_SIZE) {
+ /* this is really the same as running out of space, where we also return 0 */
+ printk(KERN_CRIT "Btrfs: free space cache was too big for the crc page\n");
+ ret = 0;
+ goto out_update;
+ }
+
/* We need a checksum per page. */
crc = checksums = kzalloc(sizeof(u32) * num_pages, GFP_NOFS);
if (!crc)
@@ -605,12 +620,6 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
return -1;
}
- /* Since the first page has all of our checksums and our generation we
- * need to calculate the offset into the page that we can start writing
- * our entries.
- */
- first_page_offset = (sizeof(u32) * num_pages) + sizeof(u64);
-
/* Get the cluster for this block_group if it exists */
if (block_group && !list_empty(&block_group->cluster_list))
cluster = list_entry(block_group->cluster_list.next,
@@ -872,12 +881,14 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
ret = 1;
out_free:
+ kfree(checksums);
+ kfree(pages);
+
+out_update:
if (ret != 1) {
invalidate_inode_pages2_range(inode->i_mapping, 0, index);
BTRFS_I(inode)->generation = 0;
}
- kfree(checksums);
- kfree(pages);
btrfs_update_inode(trans, root, inode);
return ret;
}