[PATCH 08/23] nvmet: add context annotation for nvmet_ns::blksize_shift
Nilay Shroff
nilay at linux.ibm.com
Sun Nov 8 19:28:13 PST 2026
The nvmet_ns::blksize_shift field is protected by nvmet_subsys::lock.
Annotate it with __guarded_by(&subsys->lock) to allow the Clang context
analyzer to validate accesses to this field.
The I/O hotpath also accesses nvmet_ns::blksize_shift without holding
subsys->lock. This is safe because the namespace reference held by the
I/O request prevents the namespace from being modified while the I/O is
in flight.
Introduce nvmet_ns_blksize_shift(), annotated with __context_unsafe(),
to allow these lockless accesses without triggering context analyzer
warnings. Use this accessor at all relevant call sites that access
blksize_shift without holding subsys->lock, including the namespace
identify, block I/O, file I/O, ZNS, and common LBA/sector conversion
paths.
Signed-off-by: Nilay Shroff <nilay at linux.ibm.com>
---
drivers/nvme/target/admin-cmd.c | 4 ++--
drivers/nvme/target/io-cmd-bdev.c | 4 ++--
drivers/nvme/target/io-cmd-file.c | 12 +++++++-----
drivers/nvme/target/nvmet.h | 10 ++++++----
drivers/nvme/target/zns.c | 2 +-
5 files changed, 18 insertions(+), 14 deletions(-)
diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 761caac84255..4302dba7c000 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -891,7 +891,7 @@ static void nvmet_execute_identify_ns(struct nvmet_req *req)
* that out from the underlying device.
*/
id->ncap = id->nsze =
- cpu_to_le64(req->ns->size >> req->ns->blksize_shift);
+ cpu_to_le64(req->ns->size >> nvmet_ns_blksize_shift(req->ns));
switch (req->port->ana_state[req->ns->anagrpid]) {
case NVME_ANA_INACCESSIBLE:
case NVME_ANA_PERSISTENT_LOSS:
@@ -935,7 +935,7 @@ static void nvmet_execute_identify_ns(struct nvmet_req *req)
memcpy(&id->nguid, &req->ns->nguid, sizeof(id->nguid));
- id->lbaf[0].ds = req->ns->blksize_shift;
+ id->lbaf[0].ds = nvmet_ns_blksize_shift(req->ns);
if (req->sq->ctrl->pi_support && nvmet_ns_has_pi(req->ns)) {
id->dpc = NVME_NS_DPC_PI_FIRST | NVME_NS_DPC_PI_LAST |
diff --git a/drivers/nvme/target/io-cmd-bdev.c b/drivers/nvme/target/io-cmd-bdev.c
index 7c263cb169a8..e950b442ffc6 100644
--- a/drivers/nvme/target/io-cmd-bdev.c
+++ b/drivers/nvme/target/io-cmd-bdev.c
@@ -393,7 +393,7 @@ static void nvmet_bdev_execute_discard(struct nvmet_req *req)
break;
nr_sects = (sector_t)le32_to_cpu(range.nlb) <<
- (ns->blksize_shift - 9);
+ (nvmet_ns_blksize_shift(ns) - 9);
__blkdev_issue_discard(nvmet_ns_bdev(ns),
nvmet_lba_to_sect(ns, range.slba), nr_sects,
GFP_KERNEL, &bio);
@@ -442,7 +442,7 @@ static void nvmet_bdev_execute_write_zeroes(struct nvmet_req *req)
sector = nvmet_lba_to_sect(req->ns, write_zeroes->slba);
nr_sector = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
- (req->ns->blksize_shift - 9));
+ (nvmet_ns_blksize_shift(req->ns) - 9));
ret = __blkdev_issue_zeroout(nvmet_ns_bdev(req->ns), sector, nr_sector,
GFP_KERNEL, &bio, 0);
diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
index 4307232c9160..90dbfbd16978 100644
--- a/drivers/nvme/target/io-cmd-file.c
+++ b/drivers/nvme/target/io-cmd-file.c
@@ -131,7 +131,7 @@ static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags)
if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC)
is_sync = true;
- pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift;
+ pos = le64_to_cpu(req->cmd->rw.slba) << nvmet_ns_blksize_shift(req->ns);
if (unlikely(pos + req->transfer_len > req->ns->size)) {
ret = -ENOSPC;
goto complete;
@@ -297,9 +297,10 @@ static void nvmet_file_execute_discard(struct nvmet_req *req)
if (status)
break;
- offset = le64_to_cpu(range.slba) << req->ns->blksize_shift;
+ offset = le64_to_cpu(range.slba) <<
+ nvmet_ns_blksize_shift(req->ns);
len = le32_to_cpu(range.nlb);
- len <<= req->ns->blksize_shift;
+ len <<= nvmet_ns_blksize_shift(req->ns);
if (offset + len > req->ns->size) {
req->error_slba = le64_to_cpu(range.slba);
status = errno_to_nvme_status(req, -ENOSPC);
@@ -351,9 +352,10 @@ static void nvmet_file_write_zeroes_work(struct work_struct *w)
loff_t len;
int ret;
- offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift;
+ offset = le64_to_cpu(write_zeroes->slba) <<
+ nvmet_ns_blksize_shift(req->ns);
len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
- req->ns->blksize_shift);
+ nvmet_ns_blksize_shift(req->ns));
if (unlikely(offset + len > req->ns->size)) {
nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index d03e059d6d16..1ea0566b8eea 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -159,7 +159,8 @@ struct nvmet_ns {
__guarded_by(&subsys->lock);
u32 nsid
__guarded_by(&subsys->lock);
- u32 blksize_shift;
+ u32 blksize_shift
+ __guarded_by(&subsys->lock);
loff_t size;
u8 nguid[16];
uuid_t uuid;
@@ -207,6 +208,7 @@ static inline _type nvmet_ns_##_name(struct nvmet_ns *ns) \
NVMET_NS_ACCESSOR(struct block_device *, bdev)
NVMET_NS_ACCESSOR(struct file *, file)
NVMET_NS_ACCESSOR(u32, nsid)
+NVMET_NS_ACCESSOR(u32, blksize_shift)
/*
* These accessors use data_race() and READ_ONCE() to allow lockless access to
@@ -807,7 +809,7 @@ void nvmet_bdev_execute_zone_append(struct nvmet_req *req);
static inline u32 nvmet_rw_data_len(struct nvmet_req *req)
{
return ((u32)le16_to_cpu(req->cmd->rw.length) + 1) <<
- req->ns->blksize_shift;
+ nvmet_ns_blksize_shift(req->ns);
}
static inline u32 nvmet_rw_metadata_len(struct nvmet_req *req)
@@ -1000,12 +1002,12 @@ static inline bool nvmet_ns_has_pi(struct nvmet_ns *ns)
static inline __le64 nvmet_sect_to_lba(struct nvmet_ns *ns, sector_t sect)
{
- return cpu_to_le64(sect >> (ns->blksize_shift - SECTOR_SHIFT));
+ return cpu_to_le64(sect >> (nvmet_ns_blksize_shift(ns) - SECTOR_SHIFT));
}
static inline sector_t nvmet_lba_to_sect(struct nvmet_ns *ns, __le64 lba)
{
- return le64_to_cpu(lba) << (ns->blksize_shift - SECTOR_SHIFT);
+ return le64_to_cpu(lba) << (nvmet_ns_blksize_shift(ns) - SECTOR_SHIFT);
}
static inline bool nvmet_use_inline_bvec(struct nvmet_req *req)
diff --git a/drivers/nvme/target/zns.c b/drivers/nvme/target/zns.c
index ce5309453668..9afea37862ef 100644
--- a/drivers/nvme/target/zns.c
+++ b/drivers/nvme/target/zns.c
@@ -122,7 +122,7 @@ void nvmet_execute_identify_ns_zns(struct nvmet_req *req)
}
zsze = (bdev_zone_sectors(nvmet_ns_bdev(req->ns)) << 9) >>
- req->ns->blksize_shift;
+ nvmet_ns_blksize_shift(req->ns);
id_zns->lbafe[0].zsze = cpu_to_le64(zsze);
mor = bdev_max_open_zones(nvmet_ns_bdev(req->ns));
--
2.53.0
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