From: John Garry <john.g.garry@oracle.com> mainline inclusion from mainline-v6.14-rc1 commit d279c80e0bac8a42c7d05744fefbd3b4736dd475 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/ID2HML CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- It is neater to build blk_opf_t fully in one place, so inline iomap_dio_bio_opflags() in iomap_dio_bio_iter(). Also tidy up the logic in dealing with IOMAP_DIO_CALLER_COMP, in generally separate the logic in dealing with flags associated with reads and writes. Originally-from: Christoph Hellwig <hch@lst.de> Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Signed-off-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20250320120250.4087011-2-john.g.garry@oracle.com Signed-off-by: Christian Brauner <brauner@kernel.org> Conflicts: fs/iomap/direct-io.c Signed-off-by: Long Li <leo.lilong@huawei.com> --- fs/iomap/direct-io.c | 111 +++++++++++++++++++------------------------ 1 file changed, 49 insertions(+), 62 deletions(-) diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 9d605cb6824f..aa8245f7d740 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -251,27 +251,20 @@ static void iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio *dio, } /* - * Figure out the bio's operation flags from the dio request, the - * mapping, and whether or not we want FUA. Note that we can end up - * clearing the WRITE_THROUGH flag in the dio request. + * Use a FUA write if we need datasync semantics and this is a pure data I/O + * that doesn't require any metadata updates (including after I/O completion + * such as unwritten extent conversion) and the underlying device either + * doesn't have a volatile write cache or supports FUA. + * This allows us to avoid cache flushes on I/O completion. */ -static inline blk_opf_t iomap_dio_bio_opflags(struct iomap_dio *dio, - const struct iomap *iomap, bool use_fua, bool atomic_hw) +static inline bool iomap_dio_can_use_fua(const struct iomap *iomap, + struct iomap_dio *dio) { - blk_opf_t opflags = REQ_SYNC | REQ_IDLE; - - if (!(dio->flags & IOMAP_DIO_WRITE)) - return REQ_OP_READ; - - opflags |= REQ_OP_WRITE; - if (use_fua) - opflags |= REQ_FUA; - else - dio->flags &= ~IOMAP_DIO_WRITE_THROUGH; - if (atomic_hw) - opflags |= REQ_ATOMIC; - - return opflags; + if (iomap->flags & (IOMAP_F_SHARED | IOMAP_F_DIRTY)) + return false; + if (!(dio->flags & IOMAP_DIO_WRITE_THROUGH)) + return false; + return !bdev_write_cache(iomap->bdev) || bdev_fua(iomap->bdev); } static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter, @@ -280,52 +273,59 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter, const struct iomap *iomap = &iter->iomap; struct inode *inode = iter->inode; unsigned int fs_block_size = i_blocksize(inode), pad; - bool atomic_hw = iter->flags & IOMAP_ATOMIC_HW; const loff_t length = iomap_length(iter); loff_t pos = iter->pos; - blk_opf_t bio_opf; + blk_opf_t bio_opf = REQ_SYNC | REQ_IDLE; struct bio *bio; bool need_zeroout = false; - bool use_fua = false; int nr_pages, ret = 0; size_t copied = 0; size_t orig_count; - if (atomic_hw && length != fs_block_size) - return -EINVAL; - if ((pos | length) & (bdev_logical_block_size(iomap->bdev) - 1) || !bdev_iter_is_aligned(iomap->bdev, dio->submit.iter)) return -EINVAL; - if (iomap->type == IOMAP_UNWRITTEN) { - dio->flags |= IOMAP_DIO_UNWRITTEN; - need_zeroout = true; - } + if (dio->flags & IOMAP_DIO_WRITE) { + bio_opf |= REQ_OP_WRITE; - if (iomap->flags & IOMAP_F_SHARED) - dio->flags |= IOMAP_DIO_COW; + if (iter->flags & IOMAP_ATOMIC_HW) { + if (length != iter->len) + return -EINVAL; + bio_opf |= REQ_ATOMIC; + } + + if (iomap->type == IOMAP_UNWRITTEN) { + dio->flags |= IOMAP_DIO_UNWRITTEN; + need_zeroout = true; + } + + if (iomap->flags & IOMAP_F_SHARED) + dio->flags |= IOMAP_DIO_COW; + + if (iomap->flags & IOMAP_F_NEW) { + need_zeroout = true; + } else if (iomap->type == IOMAP_MAPPED) { + if (iomap_dio_can_use_fua(iomap, dio)) + bio_opf |= REQ_FUA; + else + dio->flags &= ~IOMAP_DIO_WRITE_THROUGH; + } - if (iomap->flags & IOMAP_F_NEW) { - need_zeroout = true; - } else if (iomap->type == IOMAP_MAPPED) { /* - * Use a FUA write if we need datasync semantics, this is a pure - * data IO that doesn't require any metadata updates (including - * after IO completion such as unwritten extent conversion) and - * the underlying device either supports FUA or doesn't have - * a volatile write cache. This allows us to avoid cache flushes - * on IO completion. If we can't use writethrough and need to - * sync, disable in-task completions as dio completion will - * need to call generic_write_sync() which will do a blocking - * fsync / cache flush call. + * We can only do deferred completion for pure overwrites that + * don't require additional I/O at completion time. + * + * This rules out writes that need zeroing or extent conversion, + * extend the file size, or issue metadata I/O or cache flushes + * during completion processing. */ - if (!(iomap->flags & (IOMAP_F_SHARED|IOMAP_F_DIRTY)) && - (dio->flags & IOMAP_DIO_WRITE_THROUGH) && - (bdev_fua(iomap->bdev) || !bdev_write_cache(iomap->bdev))) - use_fua = true; - else if (dio->flags & IOMAP_DIO_NEED_SYNC) + if (need_zeroout || (pos >= i_size_read(inode)) || + ((dio->flags & IOMAP_DIO_NEED_SYNC) && + !(bio_opf & REQ_FUA))) dio->flags &= ~IOMAP_DIO_CALLER_COMP; + } else { + bio_opf |= REQ_OP_READ; } /* @@ -339,18 +339,6 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter, if (!iov_iter_count(dio->submit.iter)) goto out; - /* - * We can only do deferred completion for pure overwrites that - * don't require additional IO at completion. This rules out - * writes that need zeroing or extent conversion, extend - * the file size, or issue journal IO or cache flushes - * during completion processing. - */ - if (need_zeroout || - ((dio->flags & IOMAP_DIO_NEED_SYNC) && !use_fua) || - ((dio->flags & IOMAP_DIO_WRITE) && pos >= i_size_read(inode))) - dio->flags &= ~IOMAP_DIO_CALLER_COMP; - /* * The rules for polled IO completions follow the guidelines as the * ones we set for inline and deferred completions. If none of those @@ -371,7 +359,6 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter, * can set up the page vector appropriately for a ZONE_APPEND * operation. */ - bio_opf = iomap_dio_bio_opflags(dio, iomap, use_fua, atomic_hw); nr_pages = bio_iov_vecs_to_alloc(dio->submit.iter, BIO_MAX_VECS); do { @@ -403,7 +390,7 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter, } n = bio->bi_iter.bi_size; - if (WARN_ON_ONCE(atomic_hw && n != length)) { + if (WARN_ON_ONCE((bio_opf & REQ_ATOMIC) && n != length)) { /* * This bio should have covered the complete length, * which it doesn't, so error. We may need to zero out -- 2.39.2