fix confusion around GFP_* flags and blk_get_request

fix confusion around GFP_* flags and blk_get_request

[Christoph Hellwig]

Hi all,

this series sorts out the mess around how we use gfp flags in the
block layer get_request interface.

Changes since RFC:
  - don't switch to GFP_NOIO for allocations in blk_get_request.
    blk_get_request is used by the multipath code in potentially dead lock
    prone areas, so this will need a separate audit and maybe a flag.

[PATCH 1/6] scsi/osd: remove the gfp argument to osd_start_request

[Christoph Hellwig]

Always GFP_KERNEL, and keeping it would cause serious complications for
the next change.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/osd/osd_initiator.c | 24 +++++++++++-------------
 fs/exofs/ore.c                   | 10 +++++-----
 fs/exofs/super.c                 |  2 +-
 include/scsi/osd_initiator.h     |  6 +-----
 4 files changed, 18 insertions(+), 24 deletions(-)

diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c
index e18877177f1b..f48bae267dc2 100644
--- a/drivers/scsi/osd/osd_initiator.c
+++ b/drivers/scsi/osd/osd_initiator.c
@@ -99,7 +99,7 @@ static int _osd_get_print_system_info(struct osd_dev *od,
 	int nelem = ARRAY_SIZE(get_attrs), a = 0;
 	int ret;
 
-	or = osd_start_request(od, GFP_KERNEL);
+	or = osd_start_request(od);
 	if (!or)
 		return -ENOMEM;
 
@@ -409,16 +409,15 @@ static void _osd_request_free(struct osd_request *or)
 	kfree(or);
 }
 
-struct osd_request *osd_start_request(struct osd_dev *dev, gfp_t gfp)
+struct osd_request *osd_start_request(struct osd_dev *dev)
 {
 	struct osd_request *or;
 
-	or = _osd_request_alloc(gfp);
+	or = _osd_request_alloc(GFP_KERNEL);
 	if (!or)
 		return NULL;
 
 	or->osd_dev = dev;
-	or->alloc_flags = gfp;
 	or->timeout = dev->def_timeout;
 	or->retries = OSD_REQ_RETRIES;
 
@@ -546,7 +545,7 @@ static int _osd_realloc_seg(struct osd_request *or,
 	if (seg->alloc_size >= max_bytes)
 		return 0;
 
-	buff = krealloc(seg->buff, max_bytes, or->alloc_flags);
+	buff = krealloc(seg->buff, max_bytes, GFP_KERNEL);
 	if (!buff) {
 		OSD_ERR("Failed to Realloc %d-bytes was-%d\n", max_bytes,
 			seg->alloc_size);
@@ -728,7 +727,7 @@ static int _osd_req_list_objects(struct osd_request *or,
 		_osd_req_encode_olist(or, list);
 
 	WARN_ON(or->in.bio);
-	bio = bio_map_kern(q, list, len, or->alloc_flags);
+	bio = bio_map_kern(q, list, len, GFP_KERNEL);
 	if (IS_ERR(bio)) {
 		OSD_ERR("!!! Failed to allocate list_objects BIO\n");
 		return PTR_ERR(bio);
@@ -1190,14 +1189,14 @@ static int _req_append_segment(struct osd_request *or,
 			pad_buff = io->pad_buff;
 
 		ret = blk_rq_map_kern(io->req->q, io->req, pad_buff, padding,
-				       or->alloc_flags);
+				       GFP_KERNEL);
 		if (ret)
 			return ret;
 		io->total_bytes += padding;
 	}
 
 	ret = blk_rq_map_kern(io->req->q, io->req, seg->buff, seg->total_bytes,
-			       or->alloc_flags);
+			       GFP_KERNEL);
 	if (ret)
 		return ret;
 
@@ -1564,14 +1563,14 @@ static int _osd_req_finalize_data_integrity(struct osd_request *or,
  * osd_finalize_request and helpers
  */
 static struct request *_make_request(struct request_queue *q, bool has_write,
-			      struct _osd_io_info *oii, gfp_t flags)
+			      struct _osd_io_info *oii)
 {
 	struct request *req;
 	struct bio *bio = oii->bio;
 	int ret;
 
 	req = blk_get_request(q, has_write ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
-			flags);
+			GFP_KERNEL);
 	if (IS_ERR(req))
 		return req;
 
@@ -1589,13 +1588,12 @@ static struct request *_make_request(struct request_queue *q, bool has_write,
 static int _init_blk_request(struct osd_request *or,
 	bool has_in, bool has_out)
 {
-	gfp_t flags = or->alloc_flags;
 	struct scsi_device *scsi_device = or->osd_dev->scsi_device;
 	struct request_queue *q = scsi_device->request_queue;
 	struct request *req;
 	int ret;
 
-	req = _make_request(q, has_out, has_out ? &or->out : &or->in, flags);
+	req = _make_request(q, has_out, has_out ? &or->out : &or->in);
 	if (IS_ERR(req)) {
 		ret = PTR_ERR(req);
 		goto out;
@@ -1611,7 +1609,7 @@ static int _init_blk_request(struct osd_request *or,
 		or->out.req = req;
 		if (has_in) {
 			/* allocate bidi request */
-			req = _make_request(q, false, &or->in, flags);
+			req = _make_request(q, false, &or->in);
 			if (IS_ERR(req)) {
 				OSD_DEBUG("blk_get_request for bidi failed\n");
 				ret = PTR_ERR(req);
diff --git a/fs/exofs/ore.c b/fs/exofs/ore.c
index 3c6a9c156b7a..ddbf87246898 100644
--- a/fs/exofs/ore.c
+++ b/fs/exofs/ore.c
@@ -790,7 +790,7 @@ int ore_create(struct ore_io_state *ios)
 	for (i = 0; i < ios->oc->numdevs; i++) {
 		struct osd_request *or;
 
-		or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
+		or = osd_start_request(_ios_od(ios, i));
 		if (unlikely(!or)) {
 			ORE_ERR("%s: osd_start_request failed\n", __func__);
 			ret = -ENOMEM;
@@ -815,7 +815,7 @@ int ore_remove(struct ore_io_state *ios)
 	for (i = 0; i < ios->oc->numdevs; i++) {
 		struct osd_request *or;
 
-		or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
+		or = osd_start_request(_ios_od(ios, i));
 		if (unlikely(!or)) {
 			ORE_ERR("%s: osd_start_request failed\n", __func__);
 			ret = -ENOMEM;
@@ -847,7 +847,7 @@ static int _write_mirror(struct ore_io_state *ios, int cur_comp)
 		struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
 		struct osd_request *or;
 
-		or = osd_start_request(_ios_od(ios, dev), GFP_KERNEL);
+		or = osd_start_request(_ios_od(ios, dev));
 		if (unlikely(!or)) {
 			ORE_ERR("%s: osd_start_request failed\n", __func__);
 			ret = -ENOMEM;
@@ -966,7 +966,7 @@ int _ore_read_mirror(struct ore_io_state *ios, unsigned cur_comp)
 		return 0; /* Just an empty slot */
 
 	first_dev = per_dev->dev + first_dev % ios->layout->mirrors_p1;
-	or = osd_start_request(_ios_od(ios, first_dev), GFP_KERNEL);
+	or = osd_start_request(_ios_od(ios, first_dev));
 	if (unlikely(!or)) {
 		ORE_ERR("%s: osd_start_request failed\n", __func__);
 		return -ENOMEM;
@@ -1060,7 +1060,7 @@ static int _truncate_mirrors(struct ore_io_state *ios, unsigned cur_comp,
 		struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
 		struct osd_request *or;
 
-		or = osd_start_request(_ios_od(ios, cur_comp), GFP_KERNEL);
+		or = osd_start_request(_ios_od(ios, cur_comp));
 		if (unlikely(!or)) {
 			ORE_ERR("%s: osd_start_request failed\n", __func__);
 			return -ENOMEM;
diff --git a/fs/exofs/super.c b/fs/exofs/super.c
index 179cd5c2f52a..719a3152da80 100644
--- a/fs/exofs/super.c
+++ b/fs/exofs/super.c
@@ -229,7 +229,7 @@ void exofs_make_credential(u8 cred_a[OSD_CAP_LEN], const struct osd_obj_id *obj)
 static int exofs_read_kern(struct osd_dev *od, u8 *cred, struct osd_obj_id *obj,
 		    u64 offset, void *p, unsigned length)
 {
-	struct osd_request *or = osd_start_request(od, GFP_KERNEL);
+	struct osd_request *or = osd_start_request(od);
 /*	struct osd_sense_info osi = {.key = 0};*/
 	int ret;
 
diff --git a/include/scsi/osd_initiator.h b/include/scsi/osd_initiator.h
index a29d3086eb56..86a569d008b2 100644
--- a/include/scsi/osd_initiator.h
+++ b/include/scsi/osd_initiator.h
@@ -148,7 +148,6 @@ struct osd_request {
 		u8 *pad_buff;
 	} out, in;
 
-	gfp_t alloc_flags;
 	unsigned timeout;
 	unsigned retries;
 	unsigned sense_len;
@@ -202,14 +201,11 @@ static inline bool osd_req_is_ver1(struct osd_request *or)
  *
  * @osd_dev:    OSD device that holds the scsi-device and default values
  *              that the request is associated with.
- * @gfp:        The allocation flags to use for request allocation, and all
- *              subsequent allocations. This will be stored at
- *              osd_request->alloc_flags, can be changed by user later
  *
  * Allocate osd_request and initialize all members to the
  * default/initial state.
  */
-struct osd_request *osd_start_request(struct osd_dev *od, gfp_t gfp);
+struct osd_request *osd_start_request(struct osd_dev *od);
 
 enum osd_req_options {
 	OSD_REQ_FUA = 0x08,	/* Force Unit Access */
-- 
2.17.0

[PATCH 2/6] block: fix __get_request documentation

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 0573f9226c2d..52f2d4623ec7 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1517,7 +1517,7 @@ static struct request *__get_request(struct request_list *rl, unsigned int op,
  * @bio: bio to allocate request for (can be %NULL)
  * @flags: BLK_MQ_REQ_* flags.
  *
- * Get a free request from @q.  If %__GFP_DIRECT_RECLAIM is set in @gfp_mask,
+ * Get a free request from @q.  If %BLK_MQ_REQ_NOWAIT is set in @flags,
  * this function keeps retrying under memory pressure and fails iff @q is dead.
  *
  * Must be called with @q->queue_lock held and,
-- 
2.17.0

[PATCH 3/6] block: sanitize blk_get_request calling conventions

[Christoph Hellwig]

Switch everyone to blk_get_request_flags, and then rename
blk_get_request_flags to blk_get_request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
---
 block/blk-core.c                   | 14 +++-----------
 block/bsg.c                        |  5 ++---
 block/scsi_ioctl.c                 |  8 +++-----
 drivers/block/paride/pd.c          |  2 +-
 drivers/block/pktcdvd.c            |  2 +-
 drivers/block/sx8.c                |  2 +-
 drivers/block/virtio_blk.c         |  2 +-
 drivers/cdrom/cdrom.c              |  2 +-
 drivers/ide/ide-atapi.c            |  2 +-
 drivers/ide/ide-cd.c               |  2 +-
 drivers/ide/ide-cd_ioctl.c         |  2 +-
 drivers/ide/ide-devsets.c          |  2 +-
 drivers/ide/ide-disk.c             |  2 +-
 drivers/ide/ide-ioctls.c           |  4 ++--
 drivers/ide/ide-park.c             |  4 ++--
 drivers/ide/ide-pm.c               |  5 ++---
 drivers/ide/ide-tape.c             |  2 +-
 drivers/ide/ide-taskfile.c         |  2 +-
 drivers/md/dm-mpath.c              |  3 ++-
 drivers/mmc/core/block.c           | 12 +++++-------
 drivers/scsi/osd/osd_initiator.c   |  2 +-
 drivers/scsi/osst.c                |  2 +-
 drivers/scsi/scsi_error.c          |  2 +-
 drivers/scsi/scsi_lib.c            |  2 +-
 drivers/scsi/sg.c                  |  2 +-
 drivers/scsi/st.c                  |  2 +-
 drivers/target/target_core_pscsi.c |  3 +--
 fs/nfsd/blocklayout.c              |  2 +-
 include/linux/blkdev.h             |  5 +----
 29 files changed, 42 insertions(+), 59 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 52f2d4623ec7..5013027eae70 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1606,13 +1606,13 @@ static struct request *blk_old_get_request(struct request_queue *q,
 }
 
 /**
- * blk_get_request_flags - allocate a request
+ * blk_get_request - allocate a request
  * @q: request queue to allocate a request for
  * @op: operation (REQ_OP_*) and REQ_* flags, e.g. REQ_SYNC.
  * @flags: BLK_MQ_REQ_* flags, e.g. BLK_MQ_REQ_NOWAIT.
  */
-struct request *blk_get_request_flags(struct request_queue *q, unsigned int op,
-				      blk_mq_req_flags_t flags)
+struct request *blk_get_request(struct request_queue *q, unsigned int op,
+				blk_mq_req_flags_t flags)
 {
 	struct request *req;
 
@@ -1631,14 +1631,6 @@ struct request *blk_get_request_flags(struct request_queue *q, unsigned int op,
 
 	return req;
 }
-EXPORT_SYMBOL(blk_get_request_flags);
-
-struct request *blk_get_request(struct request_queue *q, unsigned int op,
-				gfp_t gfp_mask)
-{
-	return blk_get_request_flags(q, op, gfp_mask & __GFP_DIRECT_RECLAIM ?
-				     0 : BLK_MQ_REQ_NOWAIT);
-}
 EXPORT_SYMBOL(blk_get_request);
 
 /**
diff --git a/block/bsg.c b/block/bsg.c
index defa06c11858..30876c5fbf15 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -226,8 +226,7 @@ bsg_map_hdr(struct request_queue *q, struct sg_io_v4 *hdr, fmode_t mode)
 		return ERR_PTR(ret);
 
 	rq = blk_get_request(q, hdr->dout_xfer_len ?
-			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
-			GFP_KERNEL);
+			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
 	if (IS_ERR(rq))
 		return rq;
 
@@ -249,7 +248,7 @@ bsg_map_hdr(struct request_queue *q, struct sg_io_v4 *hdr, fmode_t mode)
 			goto out;
 		}
 
-		next_rq = blk_get_request(q, REQ_OP_SCSI_IN, GFP_KERNEL);
+		next_rq = blk_get_request(q, REQ_OP_SCSI_IN, 0);
 		if (IS_ERR(next_rq)) {
 			ret = PTR_ERR(next_rq);
 			goto out;
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 60b471f8621b..04b54f9a4152 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -321,8 +321,7 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
 		at_head = 1;
 
 	ret = -ENOMEM;
-	rq = blk_get_request(q, writing ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
-			GFP_KERNEL);
+	rq = blk_get_request(q, writing ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
 	if (IS_ERR(rq))
 		return PTR_ERR(rq);
 	req = scsi_req(rq);
@@ -449,8 +448,7 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
 
 	}
 
-	rq = blk_get_request(q, in_len ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
-			__GFP_RECLAIM);
+	rq = blk_get_request(q, in_len ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
 	if (IS_ERR(rq)) {
 		err = PTR_ERR(rq);
 		goto error_free_buffer;
@@ -538,7 +536,7 @@ static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
 	struct request *rq;
 	int err;
 
-	rq = blk_get_request(q, REQ_OP_SCSI_OUT, __GFP_RECLAIM);
+	rq = blk_get_request(q, REQ_OP_SCSI_OUT, 0);
 	if (IS_ERR(rq))
 		return PTR_ERR(rq);
 	rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c
index 27a44b97393a..8961b190e256 100644
--- a/drivers/block/paride/pd.c
+++ b/drivers/block/paride/pd.c
@@ -740,7 +740,7 @@ static int pd_special_command(struct pd_unit *disk,
 {
 	struct request *rq;
 
-	rq = blk_get_request(disk->gd->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
+	rq = blk_get_request(disk->gd->queue, REQ_OP_DRV_IN, 0);
 	if (IS_ERR(rq))
 		return PTR_ERR(rq);
 
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index c61d20c9f3f8..4880a4a9f52d 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -704,7 +704,7 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *
 	int ret = 0;
 
 	rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
-			     REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, __GFP_RECLAIM);
+			     REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
 	if (IS_ERR(rq))
 		return PTR_ERR(rq);
 
diff --git a/drivers/block/sx8.c b/drivers/block/sx8.c
index 08586dc14e85..4d90e5eba2f5 100644
--- a/drivers/block/sx8.c
+++ b/drivers/block/sx8.c
@@ -567,7 +567,7 @@ static struct carm_request *carm_get_special(struct carm_host *host)
 	if (!crq)
 		return NULL;
 
-	rq = blk_get_request(host->oob_q, REQ_OP_DRV_OUT, GFP_KERNEL);
+	rq = blk_get_request(host->oob_q, REQ_OP_DRV_OUT, 0);
 	if (IS_ERR(rq)) {
 		spin_lock_irqsave(&host->lock, flags);
 		carm_put_request(host, crq);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 4a07593c2efd..0617b9922d59 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -298,7 +298,7 @@ static int virtblk_get_id(struct gendisk *disk, char *id_str)
 	struct request *req;
 	int err;
 
-	req = blk_get_request(q, REQ_OP_DRV_IN, GFP_KERNEL);
+	req = blk_get_request(q, REQ_OP_DRV_IN, 0);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index bfc566d3f31a..9adc8c3eb0fa 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2192,7 +2192,7 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
 
 		len = nr * CD_FRAMESIZE_RAW;
 
-		rq = blk_get_request(q, REQ_OP_SCSI_IN, GFP_KERNEL);
+		rq = blk_get_request(q, REQ_OP_SCSI_IN, 0);
 		if (IS_ERR(rq)) {
 			ret = PTR_ERR(rq);
 			break;
diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index 0e6bc631a1ca..8b2b72b93885 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -92,7 +92,7 @@ int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
 	struct request *rq;
 	int error;
 
-	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
+	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, 0);
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	rq->special = (char *)pc;
 
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 5a8e8e3c22cd..32af6f063cb3 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -437,7 +437,7 @@ int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd,
 		bool delay = false;
 
 		rq = blk_get_request(drive->queue,
-			write ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN,  __GFP_RECLAIM);
+			write ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
 		memcpy(scsi_req(rq)->cmd, cmd, BLK_MAX_CDB);
 		ide_req(rq)->type = ATA_PRIV_PC;
 		rq->rq_flags |= rq_flags;
diff --git a/drivers/ide/ide-cd_ioctl.c b/drivers/ide/ide-cd_ioctl.c
index 2acca12b9c94..b1322400887b 100644
--- a/drivers/ide/ide-cd_ioctl.c
+++ b/drivers/ide/ide-cd_ioctl.c
@@ -304,7 +304,7 @@ int ide_cdrom_reset(struct cdrom_device_info *cdi)
 	struct request *rq;
 	int ret;
 
-	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
+	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, 0);
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	rq->rq_flags = RQF_QUIET;
 	blk_execute_rq(drive->queue, cd->disk, rq, 0);
diff --git a/drivers/ide/ide-devsets.c b/drivers/ide/ide-devsets.c
index 4e20747af32e..f4f8afdf8bbe 100644
--- a/drivers/ide/ide-devsets.c
+++ b/drivers/ide/ide-devsets.c
@@ -166,7 +166,7 @@ int ide_devset_execute(ide_drive_t *drive, const struct ide_devset *setting,
 	if (!(setting->flags & DS_SYNC))
 		return setting->set(drive, arg);
 
-	rq = blk_get_request(q, REQ_OP_DRV_IN, __GFP_RECLAIM);
+	rq = blk_get_request(q, REQ_OP_DRV_IN, 0);
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	scsi_req(rq)->cmd_len = 5;
 	scsi_req(rq)->cmd[0] = REQ_DEVSET_EXEC;
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index f1a7c58fe418..e3b4e659082d 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -478,7 +478,7 @@ static int set_multcount(ide_drive_t *drive, int arg)
 	if (drive->special_flags & IDE_SFLAG_SET_MULTMODE)
 		return -EBUSY;
 
-	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
+	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, 0);
 	ide_req(rq)->type = ATA_PRIV_TASKFILE;
 
 	drive->mult_req = arg;
diff --git a/drivers/ide/ide-ioctls.c b/drivers/ide/ide-ioctls.c
index 3661abb16a5f..af5119a73689 100644
--- a/drivers/ide/ide-ioctls.c
+++ b/drivers/ide/ide-ioctls.c
@@ -125,7 +125,7 @@ static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg)
 	if (NULL == (void *) arg) {
 		struct request *rq;
 
-		rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
+		rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, 0);
 		ide_req(rq)->type = ATA_PRIV_TASKFILE;
 		blk_execute_rq(drive->queue, NULL, rq, 0);
 		err = scsi_req(rq)->result ? -EIO : 0;
@@ -222,7 +222,7 @@ static int generic_drive_reset(ide_drive_t *drive)
 	struct request *rq;
 	int ret = 0;
 
-	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
+	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, 0);
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	scsi_req(rq)->cmd_len = 1;
 	scsi_req(rq)->cmd[0] = REQ_DRIVE_RESET;
diff --git a/drivers/ide/ide-park.c b/drivers/ide/ide-park.c
index 6465bcc7cea6..622f0edb3945 100644
--- a/drivers/ide/ide-park.c
+++ b/drivers/ide/ide-park.c
@@ -32,7 +32,7 @@ static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
 	}
 	spin_unlock_irq(&hwif->lock);
 
-	rq = blk_get_request(q, REQ_OP_DRV_IN, __GFP_RECLAIM);
+	rq = blk_get_request(q, REQ_OP_DRV_IN, 0);
 	scsi_req(rq)->cmd[0] = REQ_PARK_HEADS;
 	scsi_req(rq)->cmd_len = 1;
 	ide_req(rq)->type = ATA_PRIV_MISC;
@@ -47,7 +47,7 @@ static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
 	 * Make sure that *some* command is sent to the drive after the
 	 * timeout has expired, so power management will be reenabled.
 	 */
-	rq = blk_get_request(q, REQ_OP_DRV_IN, GFP_NOWAIT);
+	rq = blk_get_request(q, REQ_OP_DRV_IN, BLK_MQ_REQ_NOWAIT);
 	if (IS_ERR(rq))
 		goto out;
 
diff --git a/drivers/ide/ide-pm.c b/drivers/ide/ide-pm.c
index ad8a125defdd..59217aa1d1fb 100644
--- a/drivers/ide/ide-pm.c
+++ b/drivers/ide/ide-pm.c
@@ -19,7 +19,7 @@ int generic_ide_suspend(struct device *dev, pm_message_t mesg)
 	}
 
 	memset(&rqpm, 0, sizeof(rqpm));
-	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
+	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, 0);
 	ide_req(rq)->type = ATA_PRIV_PM_SUSPEND;
 	rq->special = &rqpm;
 	rqpm.pm_step = IDE_PM_START_SUSPEND;
@@ -90,8 +90,7 @@ int generic_ide_resume(struct device *dev)
 	}
 
 	memset(&rqpm, 0, sizeof(rqpm));
-	rq = blk_get_request_flags(drive->queue, REQ_OP_DRV_IN,
-				   BLK_MQ_REQ_PREEMPT);
+	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, BLK_MQ_REQ_PREEMPT);
 	ide_req(rq)->type = ATA_PRIV_PM_RESUME;
 	rq->special = &rqpm;
 	rqpm.pm_step = IDE_PM_START_RESUME;
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index fd57e8ccc47a..66661031f3f1 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -854,7 +854,7 @@ static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 	BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
 	BUG_ON(size < 0 || size % tape->blk_size);
 
-	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
+	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, 0);
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	scsi_req(rq)->cmd[13] = cmd;
 	rq->rq_disk = tape->disk;
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index abe0822dd429..6308bb0dab50 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -431,7 +431,7 @@ int ide_raw_taskfile(ide_drive_t *drive, struct ide_cmd *cmd, u8 *buf,
 
 	rq = blk_get_request(drive->queue,
 		(cmd->tf_flags & IDE_TFLAG_WRITE) ?
-			REQ_OP_DRV_OUT : REQ_OP_DRV_IN, __GFP_RECLAIM);
+			REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
 	ide_req(rq)->type = ATA_PRIV_TASKFILE;
 
 	/*
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 203a0419d2b0..d94ba6f72ff5 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -520,7 +520,8 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
 
 	bdev = pgpath->path.dev->bdev;
 	q = bdev_get_queue(bdev);
-	clone = blk_get_request(q, rq->cmd_flags | REQ_NOMERGE, GFP_ATOMIC);
+	clone = blk_get_request(q, rq->cmd_flags | REQ_NOMERGE,
+			BLK_MQ_REQ_NOWAIT);
 	if (IS_ERR(clone)) {
 		/* EBUSY, ENODEV or EWOULDBLOCK: requeue */
 		if (blk_queue_dying(q)) {
diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 9e923cd1d80e..6e3bde824db8 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -244,7 +244,7 @@ static ssize_t power_ro_lock_store(struct device *dev,
 	mq = &md->queue;
 
 	/* Dispatch locking to the block layer */
-	req = blk_get_request(mq->queue, REQ_OP_DRV_OUT, __GFP_RECLAIM);
+	req = blk_get_request(mq->queue, REQ_OP_DRV_OUT, 0);
 	if (IS_ERR(req)) {
 		count = PTR_ERR(req);
 		goto out_put;
@@ -650,8 +650,7 @@ static int mmc_blk_ioctl_cmd(struct mmc_blk_data *md,
 	 */
 	mq = &md->queue;
 	req = blk_get_request(mq->queue,
-		idata->ic.write_flag ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN,
-		__GFP_RECLAIM);
+		idata->ic.write_flag ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto cmd_done;
@@ -721,8 +720,7 @@ static int mmc_blk_ioctl_multi_cmd(struct mmc_blk_data *md,
 	 */
 	mq = &md->queue;
 	req = blk_get_request(mq->queue,
-		idata[0]->ic.write_flag ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN,
-		__GFP_RECLAIM);
+		idata[0]->ic.write_flag ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto cmd_err;
@@ -2750,7 +2748,7 @@ static int mmc_dbg_card_status_get(void *data, u64 *val)
 	int ret;
 
 	/* Ask the block layer about the card status */
-	req = blk_get_request(mq->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
+	req = blk_get_request(mq->queue, REQ_OP_DRV_IN, 0);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 	req_to_mmc_queue_req(req)->drv_op = MMC_DRV_OP_GET_CARD_STATUS;
@@ -2786,7 +2784,7 @@ static int mmc_ext_csd_open(struct inode *inode, struct file *filp)
 		return -ENOMEM;
 
 	/* Ask the block layer for the EXT CSD */
-	req = blk_get_request(mq->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
+	req = blk_get_request(mq->queue, REQ_OP_DRV_IN, 0);
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto out_free;
diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c
index f48bae267dc2..5a33e1ad9881 100644
--- a/drivers/scsi/osd/osd_initiator.c
+++ b/drivers/scsi/osd/osd_initiator.c
@@ -1570,7 +1570,7 @@ static struct request *_make_request(struct request_queue *q, bool has_write,
 	int ret;
 
 	req = blk_get_request(q, has_write ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
-			GFP_KERNEL);
+			0);
 	if (IS_ERR(req))
 		return req;
 
diff --git a/drivers/scsi/osst.c b/drivers/scsi/osst.c
index 20ec1c01dbd5..2bbe797f8c3d 100644
--- a/drivers/scsi/osst.c
+++ b/drivers/scsi/osst.c
@@ -368,7 +368,7 @@ static int osst_execute(struct osst_request *SRpnt, const unsigned char *cmd,
 	int write = (data_direction == DMA_TO_DEVICE);
 
 	req = blk_get_request(SRpnt->stp->device->request_queue,
-			write ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, GFP_KERNEL);
+			write ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
 	if (IS_ERR(req))
 		return DRIVER_ERROR << 24;
 
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 946039117bf4..61d280f560df 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1937,7 +1937,7 @@ static void scsi_eh_lock_door(struct scsi_device *sdev)
 	 * blk_get_request with GFP_KERNEL (__GFP_RECLAIM) sleeps until a
 	 * request becomes available
 	 */
-	req = blk_get_request(sdev->request_queue, REQ_OP_SCSI_IN, GFP_KERNEL);
+	req = blk_get_request(sdev->request_queue, REQ_OP_SCSI_IN, 0);
 	if (IS_ERR(req))
 		return;
 	rq = scsi_req(req);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index e9b4f279d29c..6b0f3ec487bd 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -265,7 +265,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 	struct scsi_request *rq;
 	int ret = DRIVER_ERROR << 24;
 
-	req = blk_get_request_flags(sdev->request_queue,
+	req = blk_get_request(sdev->request_queue,
 			data_direction == DMA_TO_DEVICE ?
 			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, BLK_MQ_REQ_PREEMPT);
 	if (IS_ERR(req))
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index c198b96368dd..0512648ebc8e 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1715,7 +1715,7 @@ sg_start_req(Sg_request *srp, unsigned char *cmd)
 	 * does not sleep except under memory pressure.
 	 */
 	rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
-			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, GFP_KERNEL);
+			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
 	if (IS_ERR(rq)) {
 		kfree(long_cmdp);
 		return PTR_ERR(rq);
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 6c399480783d..a427ce9497be 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -545,7 +545,7 @@ static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 
 	req = blk_get_request(SRpnt->stp->device->request_queue,
 			data_direction == DMA_TO_DEVICE ?
-			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, GFP_KERNEL);
+			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
 	if (IS_ERR(req))
 		return DRIVER_ERROR << 24;
 	rq = scsi_req(req);
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 6cb933ecc084..668934ea74cb 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -986,8 +986,7 @@ pscsi_execute_cmd(struct se_cmd *cmd)
 
 	req = blk_get_request(pdv->pdv_sd->request_queue,
 			cmd->data_direction == DMA_TO_DEVICE ?
-			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
-			GFP_KERNEL);
+			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
 	if (IS_ERR(req)) {
 		pr_err("PSCSI: blk_get_request() failed\n");
 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c
index 70b8bf781fce..a43dfedd69ec 100644
--- a/fs/nfsd/blocklayout.c
+++ b/fs/nfsd/blocklayout.c
@@ -227,7 +227,7 @@ static int nfsd4_scsi_identify_device(struct block_device *bdev,
 	if (!buf)
 		return -ENOMEM;
 
-	rq = blk_get_request(q, REQ_OP_SCSI_IN, GFP_KERNEL);
+	rq = blk_get_request(q, REQ_OP_SCSI_IN, 0);
 	if (IS_ERR(rq)) {
 		error = -ENOMEM;
 		goto out_free_buf;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 5c4eee043191..ffc81538a9cf 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -967,11 +967,8 @@ extern void blk_rq_init(struct request_queue *q, struct request *rq);
 extern void blk_init_request_from_bio(struct request *req, struct bio *bio);
 extern void blk_put_request(struct request *);
 extern void __blk_put_request(struct request_queue *, struct request *);
-extern struct request *blk_get_request_flags(struct request_queue *,
-					     unsigned int op,
-					     blk_mq_req_flags_t flags);
 extern struct request *blk_get_request(struct request_queue *, unsigned int op,
-				       gfp_t gfp_mask);
+				       blk_mq_req_flags_t flags);
 extern void blk_requeue_request(struct request_queue *, struct request *);
 extern int blk_lld_busy(struct request_queue *q);
 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
-- 
2.17.0

[PATCH 4/6] block: pass an explicit gfp_t to get_request

[Christoph Hellwig]

blk_old_get_request already has it at hand, and in blk_queue_bio, which
is the fast path, it is constant.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
---
 block/blk-core.c          | 14 +++++++-------
 drivers/scsi/scsi_error.c |  4 ----
 2 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 5013027eae70..cc56e56c2eff 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1333,6 +1333,7 @@ int blk_update_nr_requests(struct request_queue *q, unsigned int nr)
  * @op: operation and flags
  * @bio: bio to allocate request for (can be %NULL)
  * @flags: BLQ_MQ_REQ_* flags
+ * @gfp_mask: allocator flags
  *
  * Get a free request from @q.  This function may fail under memory
  * pressure or if @q is dead.
@@ -1342,7 +1343,7 @@ int blk_update_nr_requests(struct request_queue *q, unsigned int nr)
  * Returns request pointer on success, with @q->queue_lock *not held*.
  */
 static struct request *__get_request(struct request_list *rl, unsigned int op,
-				     struct bio *bio, blk_mq_req_flags_t flags)
+		struct bio *bio, blk_mq_req_flags_t flags, gfp_t gfp_mask)
 {
 	struct request_queue *q = rl->q;
 	struct request *rq;
@@ -1351,8 +1352,6 @@ static struct request *__get_request(struct request_list *rl, unsigned int op,
 	struct io_cq *icq = NULL;
 	const bool is_sync = op_is_sync(op);
 	int may_queue;
-	gfp_t gfp_mask = flags & BLK_MQ_REQ_NOWAIT ? GFP_ATOMIC :
-			 __GFP_DIRECT_RECLAIM;
 	req_flags_t rq_flags = RQF_ALLOCED;
 
 	lockdep_assert_held(q->queue_lock);
@@ -1516,6 +1515,7 @@ static struct request *__get_request(struct request_list *rl, unsigned int op,
  * @op: operation and flags
  * @bio: bio to allocate request for (can be %NULL)
  * @flags: BLK_MQ_REQ_* flags.
+ * @gfp: allocator flags
  *
  * Get a free request from @q.  If %BLK_MQ_REQ_NOWAIT is set in @flags,
  * this function keeps retrying under memory pressure and fails iff @q is dead.
@@ -1525,7 +1525,7 @@ static struct request *__get_request(struct request_list *rl, unsigned int op,
  * Returns request pointer on success, with @q->queue_lock *not held*.
  */
 static struct request *get_request(struct request_queue *q, unsigned int op,
-				   struct bio *bio, blk_mq_req_flags_t flags)
+		struct bio *bio, blk_mq_req_flags_t flags, gfp_t gfp)
 {
 	const bool is_sync = op_is_sync(op);
 	DEFINE_WAIT(wait);
@@ -1537,7 +1537,7 @@ static struct request *get_request(struct request_queue *q, unsigned int op,
 
 	rl = blk_get_rl(q, bio);	/* transferred to @rq on success */
 retry:
-	rq = __get_request(rl, op, bio, flags);
+	rq = __get_request(rl, op, bio, flags, gfp);
 	if (!IS_ERR(rq))
 		return rq;
 
@@ -1591,7 +1591,7 @@ static struct request *blk_old_get_request(struct request_queue *q,
 	if (ret)
 		return ERR_PTR(ret);
 	spin_lock_irq(q->queue_lock);
-	rq = get_request(q, op, NULL, flags);
+	rq = get_request(q, op, NULL, flags, gfp_mask);
 	if (IS_ERR(rq)) {
 		spin_unlock_irq(q->queue_lock);
 		blk_queue_exit(q);
@@ -2057,7 +2057,7 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio)
 	 * Returns with the queue unlocked.
 	 */
 	blk_queue_enter_live(q);
-	req = get_request(q, bio->bi_opf, bio, 0);
+	req = get_request(q, bio->bi_opf, bio, 0, __GFP_DIRECT_RECLAIM);
 	if (IS_ERR(req)) {
 		blk_queue_exit(q);
 		__wbt_done(q->rq_wb, wb_acct);
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 61d280f560df..b36e73090018 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1933,10 +1933,6 @@ static void scsi_eh_lock_door(struct scsi_device *sdev)
 	struct request *req;
 	struct scsi_request *rq;
 
-	/*
-	 * blk_get_request with GFP_KERNEL (__GFP_RECLAIM) sleeps until a
-	 * request becomes available
-	 */
 	req = blk_get_request(sdev->request_queue, REQ_OP_SCSI_IN, 0);
 	if (IS_ERR(req))
 		return;
-- 
2.17.0

[PATCH 5/6] block: use GFP_NOIO instead of __GFP_DIRECT_RECLAIM

[Christoph Hellwig]

We just can't do I/O when doing block layer requests allocations,
so use GFP_NOIO instead of the even more limited __GFP_DIRECT_RECLAIM.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
---
 block/blk-core.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index cc56e56c2eff..168e43d6398d 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1578,8 +1578,7 @@ static struct request *blk_old_get_request(struct request_queue *q,
 				unsigned int op, blk_mq_req_flags_t flags)
 {
 	struct request *rq;
-	gfp_t gfp_mask = flags & BLK_MQ_REQ_NOWAIT ? GFP_ATOMIC :
-			 __GFP_DIRECT_RECLAIM;
+	gfp_t gfp_mask = flags & BLK_MQ_REQ_NOWAIT ? GFP_ATOMIC : GFP_NOIO;
 	int ret = 0;
 
 	WARN_ON_ONCE(q->mq_ops);
@@ -2057,7 +2056,7 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio)
 	 * Returns with the queue unlocked.
 	 */
 	blk_queue_enter_live(q);
-	req = get_request(q, bio->bi_opf, bio, 0, __GFP_DIRECT_RECLAIM);
+	req = get_request(q, bio->bi_opf, bio, 0, GFP_NOIO);
 	if (IS_ERR(req)) {
 		blk_queue_exit(q);
 		__wbt_done(q->rq_wb, wb_acct);
-- 
2.17.0

[PATCH 6/6] block: consistently use GFP_NOIO instead of __GFP_NORECLAIM

[Christoph Hellwig]

Same numerical value (for now at least), but a much better documentation
of intent.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
---
 block/scsi_ioctl.c               |  2 +-
 drivers/block/drbd/drbd_bitmap.c |  3 ++-
 drivers/block/pktcdvd.c          |  2 +-
 drivers/ide/ide-tape.c           |  2 +-
 drivers/ide/ide-taskfile.c       |  2 +-
 drivers/scsi/scsi_lib.c          |  2 +-
 fs/direct-io.c                   |  4 ++--
 kernel/power/swap.c              | 14 +++++++-------
 8 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 04b54f9a4152..533f4aee8567 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -499,7 +499,7 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
 		break;
 	}
 
-	if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, __GFP_RECLAIM)) {
+	if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, GFP_NOIO)) {
 		err = DRIVER_ERROR << 24;
 		goto error;
 	}
diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c
index 9f4e6f502b84..d82237d534cf 100644
--- a/drivers/block/drbd/drbd_bitmap.c
+++ b/drivers/block/drbd/drbd_bitmap.c
@@ -1014,7 +1014,8 @@ static void bm_page_io_async(struct drbd_bm_aio_ctx *ctx, int page_nr) __must_ho
 	bm_set_page_unchanged(b->bm_pages[page_nr]);
 
 	if (ctx->flags & BM_AIO_COPY_PAGES) {
-		page = mempool_alloc(drbd_md_io_page_pool, __GFP_HIGHMEM|__GFP_RECLAIM);
+		page = mempool_alloc(drbd_md_io_page_pool,
+				GFP_NOIO | __GFP_HIGHMEM);
 		copy_highpage(page, b->bm_pages[page_nr]);
 		bm_store_page_idx(page, page_nr);
 	} else
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 4880a4a9f52d..ccfcf544830f 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -710,7 +710,7 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *
 
 	if (cgc->buflen) {
 		ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen,
-				      __GFP_RECLAIM);
+				      GFP_NOIO);
 		if (ret)
 			goto out;
 	}
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index 66661031f3f1..62c1a19a9aed 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -862,7 +862,7 @@ static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 
 	if (size) {
 		ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
-				      __GFP_RECLAIM);
+				      GFP_NOIO);
 		if (ret)
 			goto out_put;
 	}
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index 6308bb0dab50..c034cd965831 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -442,7 +442,7 @@ int ide_raw_taskfile(ide_drive_t *drive, struct ide_cmd *cmd, u8 *buf,
 	 */
 	if (nsect) {
 		error = blk_rq_map_kern(drive->queue, rq, buf,
-					nsect * SECTOR_SIZE, __GFP_RECLAIM);
+					nsect * SECTOR_SIZE, GFP_NOIO);
 		if (error)
 			goto put_req;
 	}
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 6b0f3ec487bd..f125fd71c0f2 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -273,7 +273,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 	rq = scsi_req(req);
 
 	if (bufflen &&	blk_rq_map_kern(sdev->request_queue, req,
-					buffer, bufflen, __GFP_RECLAIM))
+					buffer, bufflen, GFP_NOIO))
 		goto out;
 
 	rq->cmd_len = COMMAND_SIZE(cmd[0]);
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 874607bb6e02..093fb54cd316 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -432,8 +432,8 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
 	struct bio *bio;
 
 	/*
-	 * bio_alloc() is guaranteed to return a bio when called with
-	 * __GFP_RECLAIM and we request a valid number of vectors.
+	 * bio_alloc() is guaranteed to return a bio when allowed to sleep and
+	 * we request a valid number of vectors.
 	 */
 	bio = bio_alloc(GFP_KERNEL, nr_vecs);
 
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 11b4282c2d20..1efcb5b0c3ed 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -269,7 +269,7 @@ static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
 	struct bio *bio;
 	int error = 0;
 
-	bio = bio_alloc(__GFP_RECLAIM | __GFP_HIGH, 1);
+	bio = bio_alloc(GFP_NOIO | __GFP_HIGH, 1);
 	bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
 	bio_set_dev(bio, hib_resume_bdev);
 	bio_set_op_attrs(bio, op, op_flags);
@@ -376,7 +376,7 @@ static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 		return -ENOSPC;
 
 	if (hb) {
-		src = (void *)__get_free_page(__GFP_RECLAIM | __GFP_NOWARN |
+		src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
 		                              __GFP_NORETRY);
 		if (src) {
 			copy_page(src, buf);
@@ -384,7 +384,7 @@ static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 			ret = hib_wait_io(hb); /* Free pages */
 			if (ret)
 				return ret;
-			src = (void *)__get_free_page(__GFP_RECLAIM |
+			src = (void *)__get_free_page(GFP_NOIO |
 			                              __GFP_NOWARN |
 			                              __GFP_NORETRY);
 			if (src) {
@@ -691,7 +691,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
 	nr_threads = num_online_cpus() - 1;
 	nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 
-	page = (void *)__get_free_page(__GFP_RECLAIM | __GFP_HIGH);
+	page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
 	if (!page) {
 		pr_err("Failed to allocate LZO page\n");
 		ret = -ENOMEM;
@@ -989,7 +989,7 @@ static int get_swap_reader(struct swap_map_handle *handle,
 		last = tmp;
 
 		tmp->map = (struct swap_map_page *)
-			   __get_free_page(__GFP_RECLAIM | __GFP_HIGH);
+			   __get_free_page(GFP_NOIO | __GFP_HIGH);
 		if (!tmp->map) {
 			release_swap_reader(handle);
 			return -ENOMEM;
@@ -1261,8 +1261,8 @@ static int load_image_lzo(struct swap_map_handle *handle,
 
 	for (i = 0; i < read_pages; i++) {
 		page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
-						  __GFP_RECLAIM | __GFP_HIGH :
-						  __GFP_RECLAIM | __GFP_NOWARN |
+						  GFP_NOIO | __GFP_HIGH :
+						  GFP_NOIO | __GFP_NOWARN |
 						  __GFP_NORETRY);
 
 		if (!page[i]) {
-- 
2.17.0

Re: fix confusion around GFP_* flags and blk_get_request

[Christoph Hellwig]

Jens, any comments?

On Wed, May 09, 2018 at 09:54:02AM +0200, Christoph Hellwig wrote:
> Hi all,
> 
> this series sorts out the mess around how we use gfp flags in the
> block layer get_request interface.
> 
> Changes since RFC:
>   - don't switch to GFP_NOIO for allocations in blk_get_request.
>     blk_get_request is used by the multipath code in potentially dead lock
>     prone areas, so this will need a separate audit and maybe a flag.
---end quoted text---

Re: fix confusion around GFP_* flags and blk_get_request

[Jens Axboe]

On 5/14/18 8:38 AM, Christoph Hellwig wrote:
> Jens, any comments?

Looks good to me.

-- 
Jens Axboe

Re: [PATCH 1/6] scsi/osd: remove the gfp argument to osd_start_request

[Bart Van Assche]

T24gV2VkLCAyMDE4LTA1LTA5IGF0IDA5OjU0ICswMjAwLCBDaHJpc3RvcGggSGVsbHdpZyB3cm90
ZToNCj4gQWx3YXlzIEdGUF9LRVJORUwsIGFuZCBrZWVwaW5nIGl0IHdvdWxkIGNhdXNlIHNlcmlv
dXMgY29tcGxpY2F0aW9ucyBmb3INCj4gdGhlIG5leHQgY2hhbmdlLg0KDQpUaGlzIHBhdGNoIGRl
c2NyaXB0aW9uIGlzIHZlcnkgYnJpZWYuIFNob3VsZG4ndCB0aGUgZGVzY3JpcHRpb24gb2YgdGhp
cyBwYXRjaA0KbWVudGlvbiB3aGV0aGVyIG9yIG5vdCBhbnkgZnVuY3Rpb25hbGl0eSBpcyBjaGFu
Z2VkIChJIHRoaW5rIG5vIGZ1bmN0aW9uYWxpdHkNCmhhcyBiZWVuIGNoYW5nZWQpPw0KDQpCYXJ0
Lg0KDQoNCg0K

Re: [PATCH 1/6] scsi/osd: remove the gfp argument to osd_start_request

[Bart Van Assche]

On Wed, 2018-05-09 at 09:54 +0200, Christoph Hellwig wrote:
> Always GFP_KERNEL, and keeping it would cause serious complications for
> the next change.

This patch description is very brief. Shouldn't the description of this patch
mention whether or not any functionality is changed (I think no functionality
has been changed)?

Bart.

Re: [PATCH 2/6] block: fix __get_request documentation

[Bart Van Assche]

T24gV2VkLCAyMDE4LTA1LTA5IGF0IDA5OjU0ICswMjAwLCBDaHJpc3RvcGggSGVsbHdpZyB3cm90
ZToNCj4gU2lnbmVkLW9mZi1ieTogQ2hyaXN0b3BoIEhlbGx3aWcgPGhjaEBsc3QuZGU+DQoNClJl
dmlld2VkLWJ5OiBCYXJ0IFZhbiBBc3NjaGUgPGJhcnQudmFuYXNzY2hlQHdkYy5jb20+DQoNCg0K
DQo=

Re: [PATCH 2/6] block: fix __get_request documentation

[Bart Van Assche]

On Wed, 2018-05-09 at 09:54 +0200, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>

Re: [PATCH 3/6] block: sanitize blk_get_request calling conventions

[Bart Van Assche]

T24gV2VkLCAyMDE4LTA1LTA5IGF0IDA5OjU0ICswMjAwLCBDaHJpc3RvcGggSGVsbHdpZyB3cm90
ZToNCj4gU3dpdGNoIGV2ZXJ5b25lIHRvIGJsa19nZXRfcmVxdWVzdF9mbGFncywgYW5kIHRoZW4g
cmVuYW1lDQo+IGJsa19nZXRfcmVxdWVzdF9mbGFncyB0byBibGtfZ2V0X3JlcXVlc3QuDQoNClJl
dmlld2VkLWJ5OiBCYXJ0IFZhbiBBc3NjaGUgPGJhcnQudmFuYXNzY2hlQHdkYy5jb20+DQoNCg0K
DQo=

Re: [PATCH 3/6] block: sanitize blk_get_request calling conventions

[Bart Van Assche]

On Wed, 2018-05-09 at 09:54 +0200, Christoph Hellwig wrote:
> Switch everyone to blk_get_request_flags, and then rename
> blk_get_request_flags to blk_get_request.

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>

Re: [PATCH 4/6] block: pass an explicit gfp_t to get_request

[Bart Van Assche]

T24gV2VkLCAyMDE4LTA1LTA5IGF0IDA5OjU0ICswMjAwLCBDaHJpc3RvcGggSGVsbHdpZyB3cm90
ZToNCj4gYmxrX29sZF9nZXRfcmVxdWVzdCBhbHJlYWR5IGhhcyBpdCBhdCBoYW5kLCBhbmQgaW4g
YmxrX3F1ZXVlX2Jpbywgd2hpY2gNCj4gaXMgdGhlIGZhc3QgcGF0aCwgaXQgaXMgY29uc3RhbnQu
DQoNClJldmlld2VkLWJ5OiBCYXJ0IFZhbiBBc3NjaGUgPGJhcnQudmFuYXNzY2hlQHdkYy5jb20+
DQoNCg0K

Re: [PATCH 4/6] block: pass an explicit gfp_t to get_request

[Bart Van Assche]

On Wed, 2018-05-09 at 09:54 +0200, Christoph Hellwig wrote:
> blk_old_get_request already has it at hand, and in blk_queue_bio, which
> is the fast path, it is constant.

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>

Re: [PATCH 5/6] block: use GFP_NOIO instead of __GFP_DIRECT_RECLAIM

[Bart Van Assche]

T24gV2VkLCAyMDE4LTA1LTA5IGF0IDA5OjU0ICswMjAwLCBDaHJpc3RvcGggSGVsbHdpZyB3cm90
ZToNCj4gV2UganVzdCBjYW4ndCBkbyBJL08gd2hlbiBkb2luZyBibG9jayBsYXllciByZXF1ZXN0
cyBhbGxvY2F0aW9ucywNCj4gc28gdXNlIEdGUF9OT0lPIGluc3RlYWQgb2YgdGhlIGV2ZW4gbW9y
ZSBsaW1pdGVkIF9fR0ZQX0RJUkVDVF9SRUNMQUlNLg0KDQpSZXZpZXdlZC1ieTogQmFydCBWYW4g
QXNzY2hlIDxiYXJ0LnZhbmFzc2NoZUB3ZGMuY29tPg0KDQoNCg==

Re: [PATCH 5/6] block: use GFP_NOIO instead of __GFP_DIRECT_RECLAIM

[Bart Van Assche]

On Wed, 2018-05-09 at 09:54 +0200, Christoph Hellwig wrote:
> We just can't do I/O when doing block layer requests allocations,
> so use GFP_NOIO instead of the even more limited __GFP_DIRECT_RECLAIM.

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>

Re: [PATCH 6/6] block: consistently use GFP_NOIO instead of __GFP_NORECLAIM

[Bart Van Assche]

T24gV2VkLCAyMDE4LTA1LTA5IGF0IDA5OjU0ICswMjAwLCBDaHJpc3RvcGggSGVsbHdpZyB3cm90
ZToNCj4gU2FtZSBudW1lcmljYWwgdmFsdWUgKGZvciBub3cgYXQgbGVhc3QpLCBidXQgYSBtdWNo
IGJldHRlciBkb2N1bWVudGF0aW9uDQo+IG9mIGludGVudC4NCg0KVGhlcmUgaXMgYSB0eXBvIGlu
IHRoZSBzdWJqZWN0IG9mIHRoaXMgcGF0Y2g6IF9fR0ZQX05PUkVDTEFJTSBzaG91bGQgYmUNCmNo
YW5nZWQgaW50byBfX0dGUF9SRUNMQUlNLiBPdGhlcndpc2U6DQoNClJldmlld2VkLWJ5OiBCYXJ0
IFZhbiBBc3NjaGUgPGJhcnQudmFuYXNzY2hlQHdkYy5jb20+DQoNCg0KDQo=

Re: [PATCH 6/6] block: consistently use GFP_NOIO instead of __GFP_NORECLAIM

[Bart Van Assche]

On Wed, 2018-05-09 at 09:54 +0200, Christoph Hellwig wrote:
> Same numerical value (for now at least), but a much better documentation
> of intent.

There is a typo in the subject of this patch: __GFP_NORECLAIM should be
changed into __GFP_RECLAIM. Otherwise:

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>