| Message ID | 2ee5f090b52dc23569bf94a5a2609dfc49ac4a4b.1583789410.git.osandov@fb.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: read repair/direct I/O improvements | expand |
On 3/9/20 5:32 PM, Omar Sandoval wrote: > From: Omar Sandoval <osandov@fb.com> > > Fix a couple of issues in the btrfs_lookup_bio_sums documentation: > > * The bio doesn't need to be a btrfs_io_bio if dst was provided. Move > the declaration in the code to make that clear, too. > * dst must be large enough to hold nblocks * csum_size, not just > csum_size. > > Signed-off-by: Omar Sandoval <osandov@fb.com> > --- > fs/btrfs/file-item.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c > index 6c849e8fd5a1..fa9f4a92f74d 100644 > --- a/fs/btrfs/file-item.c > +++ b/fs/btrfs/file-item.c > @@ -242,11 +242,13 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, > /** > * btrfs_lookup_bio_sums - Look up checksums for a bio. > * @inode: inode that the bio is for. > - * @bio: bio embedded in btrfs_io_bio. > + * @bio: bio to look up. > * @offset: Unless (u64)-1, look up checksums for this offset in the file. > * If (u64)-1, use the page offsets from the bio instead. > - * @dst: Buffer of size btrfs_super_csum_size() used to return checksum. If > - * NULL, the checksum is returned in btrfs_io_bio(bio)->csum instead. > + * @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return > + * checksum (nblocks = bio->bi_iter.bi_size / sectorsize). If NULL, the > + * checksum buffer is allocated and returned in btrfs_io_bio(bio)->csum > + * instead. > * > * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise. > */ > @@ -256,7 +258,6 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, > struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); > struct bio_vec bvec; > struct bvec_iter iter; > - struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); > struct btrfs_csum_item *item = NULL; > struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; > struct btrfs_path *path; > @@ -277,6 +278,8 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, > > nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits; > if (!dst) { > + struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); > + Looks like you have some extra changes in here? Josef
On Wed, Mar 11, 2020 at 01:56:44PM -0400, Josef Bacik wrote: > On 3/9/20 5:32 PM, Omar Sandoval wrote: > > From: Omar Sandoval <osandov@fb.com> > > > > Fix a couple of issues in the btrfs_lookup_bio_sums documentation: > > > > * The bio doesn't need to be a btrfs_io_bio if dst was provided. Move > > the declaration in the code to make that clear, too. > > * dst must be large enough to hold nblocks * csum_size, not just > > csum_size. > > > > Signed-off-by: Omar Sandoval <osandov@fb.com> > > --- > > fs/btrfs/file-item.c | 11 +++++++---- > > 1 file changed, 7 insertions(+), 4 deletions(-) > > > > diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c > > index 6c849e8fd5a1..fa9f4a92f74d 100644 > > --- a/fs/btrfs/file-item.c > > +++ b/fs/btrfs/file-item.c > > @@ -242,11 +242,13 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, > > /** > > * btrfs_lookup_bio_sums - Look up checksums for a bio. > > * @inode: inode that the bio is for. > > - * @bio: bio embedded in btrfs_io_bio. > > + * @bio: bio to look up. > > * @offset: Unless (u64)-1, look up checksums for this offset in the file. > > * If (u64)-1, use the page offsets from the bio instead. > > - * @dst: Buffer of size btrfs_super_csum_size() used to return checksum. If > > - * NULL, the checksum is returned in btrfs_io_bio(bio)->csum instead. > > + * @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return > > + * checksum (nblocks = bio->bi_iter.bi_size / sectorsize). If NULL, the > > + * checksum buffer is allocated and returned in btrfs_io_bio(bio)->csum > > + * instead. > > * > > * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise. > > */ > > @@ -256,7 +258,6 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, > > struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); > > struct bio_vec bvec; > > struct bvec_iter iter; > > - struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); > > struct btrfs_csum_item *item = NULL; > > struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; > > struct btrfs_path *path; > > @@ -277,6 +278,8 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, > > nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits; > > if (!dst) { > > + struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); > > + > > Looks like you have some extra changes in here? I mentioned it in the commit message: "Move the declaration in the code to make that clear". It looks weird to document that the bio only needs to be a btrfs_io_bio if dst == NULL and then always get the btrfs_bio, even if we don't use it.
On 3/11/20 2:23 PM, Omar Sandoval wrote: > On Wed, Mar 11, 2020 at 01:56:44PM -0400, Josef Bacik wrote: >> On 3/9/20 5:32 PM, Omar Sandoval wrote: >>> From: Omar Sandoval <osandov@fb.com> >>> >>> Fix a couple of issues in the btrfs_lookup_bio_sums documentation: >>> >>> * The bio doesn't need to be a btrfs_io_bio if dst was provided. Move >>> the declaration in the code to make that clear, too. >>> * dst must be large enough to hold nblocks * csum_size, not just >>> csum_size. >>> >>> Signed-off-by: Omar Sandoval <osandov@fb.com> >>> --- >>> fs/btrfs/file-item.c | 11 +++++++---- >>> 1 file changed, 7 insertions(+), 4 deletions(-) >>> >>> diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c >>> index 6c849e8fd5a1..fa9f4a92f74d 100644 >>> --- a/fs/btrfs/file-item.c >>> +++ b/fs/btrfs/file-item.c >>> @@ -242,11 +242,13 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, >>> /** >>> * btrfs_lookup_bio_sums - Look up checksums for a bio. >>> * @inode: inode that the bio is for. >>> - * @bio: bio embedded in btrfs_io_bio. >>> + * @bio: bio to look up. >>> * @offset: Unless (u64)-1, look up checksums for this offset in the file. >>> * If (u64)-1, use the page offsets from the bio instead. >>> - * @dst: Buffer of size btrfs_super_csum_size() used to return checksum. If >>> - * NULL, the checksum is returned in btrfs_io_bio(bio)->csum instead. >>> + * @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return >>> + * checksum (nblocks = bio->bi_iter.bi_size / sectorsize). If NULL, the >>> + * checksum buffer is allocated and returned in btrfs_io_bio(bio)->csum >>> + * instead. >>> * >>> * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise. >>> */ >>> @@ -256,7 +258,6 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, >>> struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); >>> struct bio_vec bvec; >>> struct bvec_iter iter; >>> - struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); >>> struct btrfs_csum_item *item = NULL; >>> struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; >>> struct btrfs_path *path; >>> @@ -277,6 +278,8 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, >>> nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits; >>> if (!dst) { >>> + struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); >>> + >> >> Looks like you have some extra changes in here? > > I mentioned it in the commit message: "Move the declaration in the code > to make that clear". It looks weird to document that the bio only needs > to be a btrfs_io_bio if dst == NULL and then always get the btrfs_bio, > even if we don't use it. > Apparently I can't read multi-sentence bullet points. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Thanks, Josef
On 9.03.20 г. 23:32 ч., Omar Sandoval wrote: > From: Omar Sandoval <osandov@fb.com> > > Fix a couple of issues in the btrfs_lookup_bio_sums documentation: > > * The bio doesn't need to be a btrfs_io_bio if dst was provided. Move > the declaration in the code to make that clear, too. > * dst must be large enough to hold nblocks * csum_size, not just > csum_size. > > Signed-off-by: Omar Sandoval <osandov@fb.com> > --- > fs/btrfs/file-item.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c > index 6c849e8fd5a1..fa9f4a92f74d 100644 > --- a/fs/btrfs/file-item.c > +++ b/fs/btrfs/file-item.c > @@ -242,11 +242,13 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, > /** > * btrfs_lookup_bio_sums - Look up checksums for a bio. > * @inode: inode that the bio is for. > - * @bio: bio embedded in btrfs_io_bio. > + * @bio: bio to look up. > * @offset: Unless (u64)-1, look up checksums for this offset in the file. > * If (u64)-1, use the page offsets from the bio instead. > - * @dst: Buffer of size btrfs_super_csum_size() used to return checksum. If > - * NULL, the checksum is returned in btrfs_io_bio(bio)->csum instead. > + * @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return > + * checksum (nblocks = bio->bi_iter.bi_size / sectorsize). If NULL, the nit: sector here refers to btrfs' notion of a sector which is 4k and not the default understanding of 512 bytes. Dunno if it makes sense to make that a bit more emphatic. Also nblocks is really number of checksums. Looking at file-item.c I see there is only 1 menition of ncsums or csums_in_item. I guess if we can make that nblocks a bit more explicit? > + * checksum buffer is allocated and returned in btrfs_io_bio(bio)->csum > + * instead. > * > * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise. > */ > @@ -256,7 +258,6 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, > struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); > struct bio_vec bvec; > struct bvec_iter iter; > - struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); > struct btrfs_csum_item *item = NULL; > struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; > struct btrfs_path *path; > @@ -277,6 +278,8 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, > > nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits; > if (!dst) { > + struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); > + > if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) { > btrfs_bio->csum = kmalloc_array(nblocks, csum_size, > GFP_NOFS); >
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index 6c849e8fd5a1..fa9f4a92f74d 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -242,11 +242,13 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, /** * btrfs_lookup_bio_sums - Look up checksums for a bio. * @inode: inode that the bio is for. - * @bio: bio embedded in btrfs_io_bio. + * @bio: bio to look up. * @offset: Unless (u64)-1, look up checksums for this offset in the file. * If (u64)-1, use the page offsets from the bio instead. - * @dst: Buffer of size btrfs_super_csum_size() used to return checksum. If - * NULL, the checksum is returned in btrfs_io_bio(bio)->csum instead. + * @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return + * checksum (nblocks = bio->bi_iter.bi_size / sectorsize). If NULL, the + * checksum buffer is allocated and returned in btrfs_io_bio(bio)->csum + * instead. * * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise. */ @@ -256,7 +258,6 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); struct bio_vec bvec; struct bvec_iter iter; - struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); struct btrfs_csum_item *item = NULL; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct btrfs_path *path; @@ -277,6 +278,8 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits; if (!dst) { + struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); + if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) { btrfs_bio->csum = kmalloc_array(nblocks, csum_size, GFP_NOFS);