A ZONE_APPEND bio must follow hardware restrictions (e.g. not exceeding max_zone_append_sectors) not to be split. bio_iov_iter_get_pages builds such restricted bio using __bio_iov_append_get_pages if bio_op(bio) == REQ_OP_ZONE_APPEND.
To utilize it, we need to set the bio_op before calling bio_iov_iter_get_pages(). This commit introduces IOMAP_F_ZONE_APPEND, so that iomap user can set the flag to indicate they want REQ_OP_ZONE_APPEND and restricted bio. Reviewed-by: Darrick J. Wong <darrick.w...@oracle.com> Reviewed-by: Christoph Hellwig <h...@lst.de> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulka...@wdc.com> Signed-off-by: Naohiro Aota <naohiro.a...@wdc.com> --- fs/iomap/direct-io.c | 43 +++++++++++++++++++++++++++++++++++++------ include/linux/iomap.h | 1 + 2 files changed, 38 insertions(+), 6 deletions(-) diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 933f234d5bec..2273120d8ed7 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -201,6 +201,34 @@ iomap_dio_zero(struct iomap_dio *dio, struct iomap *iomap, loff_t pos, iomap_dio_submit_bio(dio, iomap, bio, pos); } +/* + * 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_FUA flag in the dio request. + */ +static inline unsigned int +iomap_dio_bio_opflags(struct iomap_dio *dio, struct iomap *iomap, bool use_fua) +{ + unsigned int opflags = REQ_SYNC | REQ_IDLE; + + if (!(dio->flags & IOMAP_DIO_WRITE)) { + WARN_ON_ONCE(iomap->flags & IOMAP_F_ZONE_APPEND); + return REQ_OP_READ; + } + + if (iomap->flags & IOMAP_F_ZONE_APPEND) + opflags |= REQ_OP_ZONE_APPEND; + else + opflags |= REQ_OP_WRITE; + + if (use_fua) + opflags |= REQ_FUA; + else + dio->flags &= ~IOMAP_DIO_WRITE_FUA; + + return opflags; +} + static loff_t iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, struct iomap_dio *dio, struct iomap *iomap) @@ -208,6 +236,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, unsigned int blkbits = blksize_bits(bdev_logical_block_size(iomap->bdev)); unsigned int fs_block_size = i_blocksize(inode), pad; unsigned int align = iov_iter_alignment(dio->submit.iter); + unsigned int bio_opf; struct bio *bio; bool need_zeroout = false; bool use_fua = false; @@ -263,6 +292,13 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, iomap_dio_zero(dio, iomap, pos - pad, pad); } + /* + * Set the operation flags early so that bio_iov_iter_get_pages + * can set up the page vector appropriately for a ZONE_APPEND + * operation. + */ + bio_opf = iomap_dio_bio_opflags(dio, iomap, use_fua); + do { size_t n; if (dio->error) { @@ -278,6 +314,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, bio->bi_ioprio = dio->iocb->ki_ioprio; bio->bi_private = dio; bio->bi_end_io = iomap_dio_bio_end_io; + bio->bi_opf = bio_opf; ret = bio_iov_iter_get_pages(bio, dio->submit.iter); if (unlikely(ret)) { @@ -293,14 +330,8 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, n = bio->bi_iter.bi_size; if (dio->flags & IOMAP_DIO_WRITE) { - bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE; - if (use_fua) - bio->bi_opf |= REQ_FUA; - else - dio->flags &= ~IOMAP_DIO_WRITE_FUA; task_io_account_write(n); } else { - bio->bi_opf = REQ_OP_READ; if (dio->flags & IOMAP_DIO_DIRTY) bio_set_pages_dirty(bio); } diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 5bd3cac4df9c..8ebb1fa6f3b7 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -55,6 +55,7 @@ struct vm_fault; #define IOMAP_F_SHARED 0x04 #define IOMAP_F_MERGED 0x08 #define IOMAP_F_BUFFER_HEAD 0x10 +#define IOMAP_F_ZONE_APPEND 0x20 /* * Flags set by the core iomap code during operations: -- 2.30.0