From d4ae1e2648daf12e433b81f5718dac4be84abd01 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 18 Jan 2017 11:11:58 -0800 Subject: 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 Cc: Christoph Hellwig --- drivers/ata/libata-scsi.c | 122 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 86 insertions(+), 36 deletions(-) (limited to 'drivers/ata') 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, @@ -2053,6 +2056,53 @@ struct ata_scsi_args { struct scsi_cmnd *cmd; }; +/** + * 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. @@ -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; } /** -- cgit