[PATCH 3.11 079/208] target/file: Update hw_max_sectors based on current block_size

From: Luis Henriques
Date: Mon Jan 13 2014 - 11:46:00 EST


3.11.10.3 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>

commit 95cadace8f3959282e76ebf8b382bd0930807d2c upstream.

This patch allows FILEIO to update hw_max_sectors based on the current
max_bytes_per_io. This is required because vfs_[writev,readv]() can accept
a maximum of 2048 iovecs per call, so the enforced hw_max_sectors really
needs to be calculated based on block_size.

This addresses a >= v3.5 bug where block_size=512 was rejecting > 1M
sized I/O requests, because FD_MAX_SECTORS was hardcoded to 2048 for
the block_size=4096 case.

(v2: Use max_bytes_per_io instead of ->update_hw_max_sectors)

Reported-by: Henrik Goldman <hg@xxxxxxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
drivers/target/target_core_device.c | 5 +++++
drivers/target/target_core_file.c | 8 ++++----
drivers/target/target_core_file.h | 5 ++++-
include/target/target_core_base.h | 1 +
4 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 8f4142f..717d35b 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -1078,6 +1078,11 @@ int se_dev_set_block_size(struct se_device *dev, u32 block_size)
dev->dev_attrib.block_size = block_size;
pr_debug("dev[%p]: SE Device block_size changed to %u\n",
dev, block_size);
+
+ if (dev->dev_attrib.max_bytes_per_io)
+ dev->dev_attrib.hw_max_sectors =
+ dev->dev_attrib.max_bytes_per_io / block_size;
+
return 0;
}

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index b11890d..3b28793 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -66,9 +66,8 @@ static int fd_attach_hba(struct se_hba *hba, u32 host_id)
pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
" Target Core Stack %s\n", hba->hba_id, FD_VERSION,
TARGET_CORE_MOD_VERSION);
- pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic"
- " MaxSectors: %u\n",
- hba->hba_id, fd_host->fd_host_id, FD_MAX_SECTORS);
+ pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic\n",
+ hba->hba_id, fd_host->fd_host_id);

return 0;
}
@@ -220,7 +219,8 @@ static int fd_configure_device(struct se_device *dev)
}

dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
- dev->dev_attrib.hw_max_sectors = FD_MAX_SECTORS;
+ dev->dev_attrib.max_bytes_per_io = FD_MAX_BYTES;
+ dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;

if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
diff --git a/drivers/target/target_core_file.h b/drivers/target/target_core_file.h
index 37ffc5b..d7772c1 100644
--- a/drivers/target/target_core_file.h
+++ b/drivers/target/target_core_file.h
@@ -7,7 +7,10 @@
#define FD_DEVICE_QUEUE_DEPTH 32
#define FD_MAX_DEVICE_QUEUE_DEPTH 128
#define FD_BLOCKSIZE 512
-#define FD_MAX_SECTORS 2048
+/*
+ * Limited by the number of iovecs (2048) per vfs_[writev,readv] call
+ */
+#define FD_MAX_BYTES 8388608

#define RRF_EMULATE_CDB 0x01
#define RRF_GOT_LBA 0x02
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index e34fc90..93e7991 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -604,6 +604,7 @@ struct se_dev_attrib {
u32 unmap_granularity;
u32 unmap_granularity_alignment;
u32 max_write_same_len;
+ u32 max_bytes_per_io;
struct se_device *da_dev;
struct config_group da_group;
};
--
1.8.3.2

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