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authorTejun Heo <tj@kernel.org>2017-01-18 11:11:58 -0800
committerTejun Heo <tj@kernel.org>2017-01-18 11:15:29 -0800
commitd4ae1e2648daf12e433b81f5718dac4be84abd01 (patch)
tree8e8c377e4810f8a5328d3159852a0917b32e3724 /drivers/ata
parentd7969f5976a35b48ba4eb60aaad73535f1792019 (diff)
downloadlinux-d4ae1e2648daf12e433b81f5718dac4be84abd01.tar.bz2
Revert "libata: switch to dynamic allocation instead of ata_scsi_rbuf"
This reverts commit a234f7395c9301a5048cb2daa4c86f15c6f02de8. The commit tried to get rid of the shared global SCSI response buffer. Unfortunately, it added blocking allocation to atomic path. Revert it for now. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/ata')
-rw-r--r--drivers/ata/libata-scsi.c122
1 files changed, 86 insertions, 36 deletions
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 4de273b77abc..395c8591980f 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -57,6 +57,9 @@
#define ATA_SCSI_RBUF_SIZE 4096
+static DEFINE_SPINLOCK(ata_scsi_rbuf_lock);
+static u8 ata_scsi_rbuf[ATA_SCSI_RBUF_SIZE];
+
typedef unsigned int (*ata_xlat_func_t)(struct ata_queued_cmd *qc);
static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,
@@ -2054,6 +2057,53 @@ struct ata_scsi_args {
};
/**
+ * ata_scsi_rbuf_get - Map response buffer.
+ * @cmd: SCSI command containing buffer to be mapped.
+ * @flags: unsigned long variable to store irq enable status
+ * @copy_in: copy in from user buffer
+ *
+ * Prepare buffer for simulated SCSI commands.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(ata_scsi_rbuf_lock) on success
+ *
+ * RETURNS:
+ * Pointer to response buffer.
+ */
+static void *ata_scsi_rbuf_get(struct scsi_cmnd *cmd, bool copy_in,
+ unsigned long *flags)
+{
+ spin_lock_irqsave(&ata_scsi_rbuf_lock, *flags);
+
+ memset(ata_scsi_rbuf, 0, ATA_SCSI_RBUF_SIZE);
+ if (copy_in)
+ sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
+ ata_scsi_rbuf, ATA_SCSI_RBUF_SIZE);
+ return ata_scsi_rbuf;
+}
+
+/**
+ * ata_scsi_rbuf_put - Unmap response buffer.
+ * @cmd: SCSI command containing buffer to be unmapped.
+ * @copy_out: copy out result
+ * @flags: @flags passed to ata_scsi_rbuf_get()
+ *
+ * Returns rbuf buffer. The result is copied to @cmd's buffer if
+ * @copy_back is true.
+ *
+ * LOCKING:
+ * Unlocks ata_scsi_rbuf_lock.
+ */
+static inline void ata_scsi_rbuf_put(struct scsi_cmnd *cmd, bool copy_out,
+ unsigned long *flags)
+{
+ if (copy_out)
+ sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
+ ata_scsi_rbuf, ATA_SCSI_RBUF_SIZE);
+ spin_unlock_irqrestore(&ata_scsi_rbuf_lock, *flags);
+}
+
+/**
* ata_scsi_rbuf_fill - wrapper for SCSI command simulators
* @args: device IDENTIFY data / SCSI command of interest.
* @actor: Callback hook for desired SCSI command simulator
@@ -2071,22 +2121,17 @@ struct ata_scsi_args {
static void ata_scsi_rbuf_fill(struct ata_scsi_args *args,
unsigned int (*actor)(struct ata_scsi_args *args, u8 *rbuf))
{
+ u8 *rbuf;
+ unsigned int rc;
struct scsi_cmnd *cmd = args->cmd;
- u8 *buf;
+ unsigned long flags;
- buf = kzalloc(ATA_SCSI_RBUF_SIZE, GFP_NOIO);
- if (!buf) {
- ata_scsi_set_sense(args->dev, cmd, NOT_READY, 0x08, 0);
- return;
- }
+ rbuf = ata_scsi_rbuf_get(cmd, false, &flags);
+ rc = actor(args, rbuf);
+ ata_scsi_rbuf_put(cmd, rc == 0, &flags);
- if (actor(args, buf) == 0) {
- sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
- buf, ATA_SCSI_RBUF_SIZE);
+ if (rc == 0)
cmd->result = SAM_STAT_GOOD;
- }
-
- kfree(buf);
}
/**
@@ -3318,17 +3363,24 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc)
*
* Return: Number of bytes copied into sglist.
*/
-static ssize_t ata_format_dsm_trim_descr(struct scsi_cmnd *cmd, u32 trmax,
+static size_t ata_format_dsm_trim_descr(struct scsi_cmnd *cmd, u32 trmax,
u64 sector, u32 count)
{
+ struct scsi_device *sdp = cmd->device;
+ size_t len = sdp->sector_size;
size_t r;
__le64 *buf;
u32 i = 0;
+ unsigned long flags;
- buf = kzalloc(cmd->device->sector_size, GFP_NOFS);
- if (!buf)
- return -ENOMEM;
+ WARN_ON(len > ATA_SCSI_RBUF_SIZE);
+ if (len > ATA_SCSI_RBUF_SIZE)
+ len = ATA_SCSI_RBUF_SIZE;
+
+ spin_lock_irqsave(&ata_scsi_rbuf_lock, flags);
+ buf = ((void *)ata_scsi_rbuf);
+ memset(buf, 0, len);
while (i < trmax) {
u64 entry = sector |
((u64)(count > 0xffff ? 0xffff : count) << 48);
@@ -3338,9 +3390,9 @@ static ssize_t ata_format_dsm_trim_descr(struct scsi_cmnd *cmd, u32 trmax,
count -= 0xffff;
sector += 0xffff;
}
- r = sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), buf,
- cmd->device->sector_size);
- kfree(buf);
+ r = sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), buf, len);
+ spin_unlock_irqrestore(&ata_scsi_rbuf_lock, flags);
+
return r;
}
@@ -3356,15 +3408,16 @@ static ssize_t ata_format_dsm_trim_descr(struct scsi_cmnd *cmd, u32 trmax,
*
* Return: Number of bytes copied into sglist.
*/
-static ssize_t ata_format_sct_write_same(struct scsi_cmnd *cmd, u64 lba,
- u64 num)
+static size_t ata_format_sct_write_same(struct scsi_cmnd *cmd, u64 lba, u64 num)
{
+ struct scsi_device *sdp = cmd->device;
+ size_t len = sdp->sector_size;
size_t r;
u16 *buf;
+ unsigned long flags;
- buf = kzalloc(cmd->device->sector_size, GFP_NOIO);
- if (!buf)
- return -ENOMEM;
+ spin_lock_irqsave(&ata_scsi_rbuf_lock, flags);
+ buf = ((void *)ata_scsi_rbuf);
put_unaligned_le16(0x0002, &buf[0]); /* SCT_ACT_WRITE_SAME */
put_unaligned_le16(0x0101, &buf[1]); /* WRITE PTRN FG */
@@ -3372,9 +3425,14 @@ static ssize_t ata_format_sct_write_same(struct scsi_cmnd *cmd, u64 lba,
put_unaligned_le64(num, &buf[6]);
put_unaligned_le32(0u, &buf[10]); /* pattern */
- r = sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), buf,
- cmd->device->sector_size);
- kfree(buf);
+ WARN_ON(len > ATA_SCSI_RBUF_SIZE);
+
+ if (len > ATA_SCSI_RBUF_SIZE)
+ len = ATA_SCSI_RBUF_SIZE;
+
+ r = sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), buf, len);
+ spin_unlock_irqrestore(&ata_scsi_rbuf_lock, flags);
+
return r;
}
@@ -3399,7 +3457,7 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc)
u64 block;
u32 n_block;
const u32 trmax = len >> 3;
- ssize_t size;
+ u32 size;
u16 fp;
u8 bp = 0xff;
u8 unmap = cdb[1] & 0x8;
@@ -3450,8 +3508,6 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc)
*/
if (unmap) {
size = ata_format_dsm_trim_descr(scmd, trmax, block, n_block);
- if (size < 0)
- goto comm_fail;
if (size != len)
goto invalid_param_len;
@@ -3475,8 +3531,6 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc)
}
} else {
size = ata_format_sct_write_same(scmd, block, n_block);
- if (size < 0)
- goto comm_fail;
if (size != len)
goto invalid_param_len;
@@ -3515,10 +3569,6 @@ invalid_opcode:
/* "Invalid command operation code" */
ata_scsi_set_sense(dev, scmd, ILLEGAL_REQUEST, 0x20, 0x0);
return 1;
-comm_fail:
- /* "Logical unit communication failure" */
- ata_scsi_set_sense(dev, scmd, NOT_READY, 0x08, 0);
- return 1;
}
/**