4.9-stable review patch. If anyone has any objections, please let me know.
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From: David Sterba dsterba@suse.com
commit e2683fc9d219430f5b78889b50cde7f40efeba7b upstream.
I've noticed that the updated item checker stack consumption increased dramatically in 542f5385e20cf97447 ("btrfs: tree-checker: Add checker for dir item")
tree-checker.c:check_leaf +552 (176 -> 728)
The array is 255 bytes long, dynamic allocation would slow down the sanity checks so it's more reasonable to keep it on-stack. Moving the variable to the scope of use reduces the stack usage again
tree-checker.c:check_leaf -264 (728 -> 464)
Reviewed-by: Josef Bacik jbacik@fb.com Reviewed-by: Qu Wenruo wqu@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/tree-checker.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -212,7 +212,6 @@ static int check_dir_item(struct btrfs_r
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); while (cur < item_size) { - char namebuf[max(BTRFS_NAME_LEN, XATTR_NAME_MAX)]; u32 name_len; u32 data_len; u32 max_name_len; @@ -295,6 +294,8 @@ static int check_dir_item(struct btrfs_r */ if (key->type == BTRFS_DIR_ITEM_KEY || key->type == BTRFS_XATTR_ITEM_KEY) { + char namebuf[max(BTRFS_NAME_LEN, XATTR_NAME_MAX)]; + read_extent_buffer(leaf, namebuf, (unsigned long)(di + 1), name_len); name_hash = btrfs_name_hash(namebuf, name_len);