On Tue, 2013-12-17 at 09:32 +0100, Christoph Hellwig wrote:
> On Mon, Dec 16, 2013 at 10:58:31AM -0800, Nicholas A. Bellinger wrote:
> > Sectors is what EVPD=0xb0 reports and sbc_parse_cdb() enforces for
> > backends.
>
> But it's obviously not what backends care about, given that fileio
> has a byte size limit, and the others haven no limit at all.
>
> Just store the byte limit, divide that by the block size where you
> currently use the sector count, and get rid of the stupid method.
>
Fair enough.
--nab
>From f8da26556afad9e1a8d2e47cf732cf5f06ad5327 Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Date: Thu, 12 Dec 2013 12:24:11 -0800
Subject: [PATCH] target/file: Update hw_max_sectors based on current
block_size
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>
Cc: <stable@xxxxxxxxxxxxxxx> #3.5+
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
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 207b340..d06de84 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -1106,6 +1106,11 @@ 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 0e34cda..78241a5 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..d1adf24 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 9f1dda6..321301c 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -620,6 +620,7 @@ 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;
};
--
1.7.10.4
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