Re: [PATCH] Btrfs: use larger limit for transition of logical to inode
From: Jan Schmidt <hidden>
Date: 2012-08-23 10:07:27
On Thu, August 23, 2012 at 10:56 (+0200), Liu Bo wrote:
quoted hunk ↗ jump to hunk
This is the change of the kernel side. Transition of logical to inode used to have a limit 4096 on inode container's size, but the limit is not large enough for a data with a great many of refs, so when resolving logical address, we can end up with "ioctl ret=0, bytes_left=0, bytes_missing=19944, cnt=510, missed=2493" This changes to regard 4096 as the lowest limit. Signed-off-by: Liu Bo <redacted> --- fs/btrfs/ioctl.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 9449b84..525915f 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c@@ -3232,7 +3232,7 @@ static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root, goto out; } - size = min_t(u32, loi->size, 4096); + size = max_t(u32, loi->size, 4096);
Hum. I added this because I wanted to avoid allocations > PAGE_SIZE. We're doing kmalloc GFP_NOFS with whatever one enters as size, I'm not sure that's a good idea without any sanitizing. Second, we should probably add a fall back option to vmalloc, in case kmalloc fails? Or should we even go for vmalloc directly, what do you think? Thanks, -Jan
inodes = init_data_container(size);
if (IS_ERR(inodes)) {
ret = PTR_ERR(inodes);