From: Qu Wenruo <wqu@suse.com> To: linux-btrfs@vger.kernel.org Cc: linux-block@vger.kernel.org, dm-devel@redhat.com Subject: [PATCH RFC 05/11] btrfs: save bio::bi_iter into btrfs_bio::iter before submitting Date: Sun, 28 Nov 2021 13:52:53 +0800 [thread overview] Message-ID: <20211128055259.39249-6-wqu@suse.com> (raw) In-Reply-To: <20211128055259.39249-1-wqu@suse.com> Since block layer will advance bio::bi_iter, at endio time we can no longer rely on bio::bi_iter for split bio. But for the incoming btrfs_bio split at btrfs_map_bio() time, we have to ensure endio function is only executed for the split range, not the whole original bio. Thus this patch will introduce a new helper, btrfs_bio_save_iter(), to save bi_iter into btrfs_bio::iter. The following call sites need this helper call: - btrfs_submit_compressed_read() For compressed read. For compressed write it doesn't really care as they use ordered extent. - raid56_parity_write() - raid56_parity_recovery() For RAID56. - submit_stripe_bio() For all other cases. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/compression.c | 3 +++ fs/btrfs/raid56.c | 2 ++ fs/btrfs/volumes.c | 11 +++++++++++ fs/btrfs/volumes.h | 19 +++++++++++++++++++ 4 files changed, 35 insertions(+) diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 64f931fc11f0..943e5898fa87 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -867,6 +867,9 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, /* include any pages we added in add_ra-bio_pages */ cb->len = bio->bi_iter.bi_size; + /* Save bi_iter so that end_bio_extent_readpage() won't freak out. */ + btrfs_bio_save_iter(btrfs_bio(bio)); + while (cur_disk_byte < disk_bytenr + compressed_len) { u64 offset = cur_disk_byte - disk_bytenr; unsigned int index = offset >> PAGE_SHIFT; diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c index 0e239a4c3b26..13e726c88a81 100644 --- a/fs/btrfs/raid56.c +++ b/fs/btrfs/raid56.c @@ -1731,6 +1731,7 @@ int raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc, return PTR_ERR(rbio); } bio_list_add(&rbio->bio_list, bio); + btrfs_bio_save_iter(btrfs_bio(bio)); rbio->bio_list_bytes = bio->bi_iter.bi_size; rbio->operation = BTRFS_RBIO_WRITE; @@ -2135,6 +2136,7 @@ int raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc, rbio->operation = BTRFS_RBIO_READ_REBUILD; bio_list_add(&rbio->bio_list, bio); + btrfs_bio_save_iter(btrfs_bio(bio)); rbio->bio_list_bytes = bio->bi_iter.bi_size; rbio->faila = find_logical_bio_stripe(rbio, bio); diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index f7449bf7a595..e6ed71195e18 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6771,6 +6771,17 @@ static int submit_stripe_bio(struct btrfs_io_context *bioc, struct bio *bio, dev->devid, bio->bi_iter.bi_size); bio_set_dev(bio, dev->bdev); + /* + * At endio time, bi_iter is no longer reliable, thus we have to save + * current bi_iter into btrfs_bio so that even for split bio we can + * iterate only the split part. + * + * For bio create by btrfs_bio_slit() or btrfs_bio_clone*(), it's + * already set, but we can still have original bio which has its + * iter not initialized. + */ + btrfs_bio_save_iter(btrfs_bio(bio)); + /* Do the final endio remap if needed */ ret = btrfs_bio_final_endio_remap(fs_info, bio); if (ret < 0) diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 358fc546d611..baccf895a544 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -378,6 +378,13 @@ struct btrfs_bio { bio_end_io_t *orig_endio; }; }; + + /* + * Saved bio::bi_iter before submission. + * + * This allows us to interate the cloned/split bio properly, as at + * endio time bio::bi_iter is no longer reliable. + */ struct bvec_iter iter; /* @@ -400,6 +407,18 @@ static inline void btrfs_bio_free_csum(struct btrfs_bio *bbio) } } +/* + * To save bbio::bio->bi_iter into bbio::iter so for callers who need the + * original bi_iter can access the original part of the bio. + * This is especially important for the incoming split btrfs_bio, which needs + * to call its endio for and only for the split range. + */ +static inline void btrfs_bio_save_iter(struct btrfs_bio *bbio) +{ + if (!bbio->iter.bi_size) + bbio->iter = bbio->bio.bi_iter; +} + struct btrfs_io_stripe { struct btrfs_device *dev; u64 physical; -- 2.34.0
WARNING: multiple messages have this Message-ID (diff)
From: Qu Wenruo <wqu@suse.com> To: linux-btrfs@vger.kernel.org Cc: linux-block@vger.kernel.org, dm-devel@redhat.com Subject: [dm-devel] [PATCH RFC 05/11] btrfs: save bio::bi_iter into btrfs_bio::iter before submitting Date: Sun, 28 Nov 2021 13:52:53 +0800 [thread overview] Message-ID: <20211128055259.39249-6-wqu@suse.com> (raw) In-Reply-To: <20211128055259.39249-1-wqu@suse.com> Since block layer will advance bio::bi_iter, at endio time we can no longer rely on bio::bi_iter for split bio. But for the incoming btrfs_bio split at btrfs_map_bio() time, we have to ensure endio function is only executed for the split range, not the whole original bio. Thus this patch will introduce a new helper, btrfs_bio_save_iter(), to save bi_iter into btrfs_bio::iter. The following call sites need this helper call: - btrfs_submit_compressed_read() For compressed read. For compressed write it doesn't really care as they use ordered extent. - raid56_parity_write() - raid56_parity_recovery() For RAID56. - submit_stripe_bio() For all other cases. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/compression.c | 3 +++ fs/btrfs/raid56.c | 2 ++ fs/btrfs/volumes.c | 11 +++++++++++ fs/btrfs/volumes.h | 19 +++++++++++++++++++ 4 files changed, 35 insertions(+) diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 64f931fc11f0..943e5898fa87 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -867,6 +867,9 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, /* include any pages we added in add_ra-bio_pages */ cb->len = bio->bi_iter.bi_size; + /* Save bi_iter so that end_bio_extent_readpage() won't freak out. */ + btrfs_bio_save_iter(btrfs_bio(bio)); + while (cur_disk_byte < disk_bytenr + compressed_len) { u64 offset = cur_disk_byte - disk_bytenr; unsigned int index = offset >> PAGE_SHIFT; diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c index 0e239a4c3b26..13e726c88a81 100644 --- a/fs/btrfs/raid56.c +++ b/fs/btrfs/raid56.c @@ -1731,6 +1731,7 @@ int raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc, return PTR_ERR(rbio); } bio_list_add(&rbio->bio_list, bio); + btrfs_bio_save_iter(btrfs_bio(bio)); rbio->bio_list_bytes = bio->bi_iter.bi_size; rbio->operation = BTRFS_RBIO_WRITE; @@ -2135,6 +2136,7 @@ int raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc, rbio->operation = BTRFS_RBIO_READ_REBUILD; bio_list_add(&rbio->bio_list, bio); + btrfs_bio_save_iter(btrfs_bio(bio)); rbio->bio_list_bytes = bio->bi_iter.bi_size; rbio->faila = find_logical_bio_stripe(rbio, bio); diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index f7449bf7a595..e6ed71195e18 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6771,6 +6771,17 @@ static int submit_stripe_bio(struct btrfs_io_context *bioc, struct bio *bio, dev->devid, bio->bi_iter.bi_size); bio_set_dev(bio, dev->bdev); + /* + * At endio time, bi_iter is no longer reliable, thus we have to save + * current bi_iter into btrfs_bio so that even for split bio we can + * iterate only the split part. + * + * For bio create by btrfs_bio_slit() or btrfs_bio_clone*(), it's + * already set, but we can still have original bio which has its + * iter not initialized. + */ + btrfs_bio_save_iter(btrfs_bio(bio)); + /* Do the final endio remap if needed */ ret = btrfs_bio_final_endio_remap(fs_info, bio); if (ret < 0) diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 358fc546d611..baccf895a544 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -378,6 +378,13 @@ struct btrfs_bio { bio_end_io_t *orig_endio; }; }; + + /* + * Saved bio::bi_iter before submission. + * + * This allows us to interate the cloned/split bio properly, as at + * endio time bio::bi_iter is no longer reliable. + */ struct bvec_iter iter; /* @@ -400,6 +407,18 @@ static inline void btrfs_bio_free_csum(struct btrfs_bio *bbio) } } +/* + * To save bbio::bio->bi_iter into bbio::iter so for callers who need the + * original bi_iter can access the original part of the bio. + * This is especially important for the incoming split btrfs_bio, which needs + * to call its endio for and only for the split range. + */ +static inline void btrfs_bio_save_iter(struct btrfs_bio *bbio) +{ + if (!bbio->iter.bi_size) + bbio->iter = bbio->bio.bi_iter; +} + struct btrfs_io_stripe { struct btrfs_device *dev; u64 physical; -- 2.34.0 -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel
next prev parent reply other threads:[~2021-11-28 5:55 UTC|newest] Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-11-28 5:52 [PATCH RFC 00/11] btrfs: split bio at btrfs_map_bio() time Qu Wenruo 2021-11-28 5:52 ` [dm-devel] " Qu Wenruo 2021-11-28 5:52 ` [PATCH RFC 01/11] btrfs: update an stale comment on btrfs_submit_bio_hook() Qu Wenruo 2021-11-28 5:52 ` [dm-devel] " Qu Wenruo 2021-11-28 5:52 ` [PATCH RFC 02/11] btrfs: refactor btrfs_map_bio() Qu Wenruo 2021-11-28 5:52 ` [dm-devel] " Qu Wenruo 2021-11-28 5:52 ` [PATCH RFC 03/11] btrfs: move btrfs_bio_wq_end_io() calls into submit_stripe_bio() Qu Wenruo 2021-11-28 5:52 ` [dm-devel] " Qu Wenruo 2021-11-28 5:52 ` [PATCH RFC 04/11] btrfs: introduce btrfs_bio_split() helper Qu Wenruo 2021-11-28 5:52 ` [dm-devel] " Qu Wenruo 2021-11-28 5:52 ` Qu Wenruo [this message] 2021-11-28 5:52 ` [dm-devel] [PATCH RFC 05/11] btrfs: save bio::bi_iter into btrfs_bio::iter before submitting Qu Wenruo 2021-11-28 5:52 ` [PATCH RFC 06/11] btrfs: make end_bio_extent_readpage() to handle split bio properly Qu Wenruo 2021-11-28 5:52 ` [dm-devel] " Qu Wenruo 2021-11-28 5:52 ` [PATCH RFC 07/11] btrfs: make end_bio_extent_*_writepage() to handle split biot properly Qu Wenruo 2021-11-28 5:52 ` [dm-devel] " Qu Wenruo 2021-11-28 5:52 ` [PATCH RFC 08/11] btrfs: allow btrfs_map_bio() to split bio according to chunk stripe boundaries Qu Wenruo 2021-11-28 5:52 ` [dm-devel] " Qu Wenruo 2021-11-28 5:52 ` [PATCH RFC 09/11] btrfs: remove bio split operations in btrfs_submit_direct() Qu Wenruo 2021-11-28 5:52 ` [dm-devel] " Qu Wenruo 2021-11-30 13:54 ` [btrfs] 675923ac06: BUG:KASAN:use-after-free_in__blk_queue_split kernel test robot 2021-11-30 13:54 ` kernel test robot 2021-11-30 13:54 ` [dm-devel] " kernel test robot 2021-11-28 5:52 ` [PATCH RFC 10/11] btrfs: remove btrfs_bio_ctrl::len_to_stripe_boundary Qu Wenruo 2021-11-28 5:52 ` [dm-devel] " Qu Wenruo 2021-11-28 5:52 ` [PATCH RFC 11/11] btrfs: temporarily disable RAID56 Qu Wenruo 2021-11-28 5:52 ` [dm-devel] " Qu Wenruo
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