On Thu, Oct 14, 2021 at 03:05:54PM +0300, Nikolay Borisov wrote: > > > On 1.09.21 г. 20:00, Omar Sandoval wrote: > > From: Omar Sandoval <osandov@xxxxxx> > > > > btrfs_csum_one_bio() loops over each filesystem block in the bio while > > keeping a cursor of its current logical position in the file in order to > > look up the ordered extent to add the checksums to. However, this > > doesn't make much sense for compressed extents, as a sector on disk does > > not correspond to a sector of decompressed file data. It happens to work > > because 1) the compressed bio always covers one ordered extent and 2) > > the size of the bio is always less than the size of the ordered extent. > > However, the second point will not always be true for encoded writes. > > > > Let's add a boolean parameter to btrfs_csum_one_bio() to indicate that > > it can assume that the bio only covers one ordered extent. Since we're > > already changing the signature, let's get rid of the contig parameter > > and make it implied by the offset parameter, similar to the change we > > recently made to btrfs_lookup_bio_sums(). Additionally, let's rename > > nr_sectors to blockcount to make it clear that it's the number of > > filesystem blocks, not the number of 512-byte sectors. > > > > Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx> > > Signed-off-by: Omar Sandoval <osandov@xxxxxx> > > Code-wise this looks, though I don't know why we are guaranteed that a > compressed extent will only cover a single OE. See submit_compressed_extents(): we always add an ordered extent that covers the whole range that we're submitting, and then btrfs_submit_compressed_write() creates one or more bios that are subsets of that range. > But I trust you so: > Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx> Thanks!
