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.wong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@xxxxxxx>
Signed-off-by: Naohiro Aota <naohiro.aota@xxxxxxx>
---
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:
--
2.27.0
