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libata: Safely overwrite attached page in WRITE SAME xlat

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Safely overwriting the attached page to ATA format from the SCSI formatted
variant.

Signed-off-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Shaun Tancheff 2016-08-21 23:23:18 -05:00 committed by Tejun Heo
parent cd27396e61
commit 9379e6b8e0
2 changed files with 51 additions and 31 deletions
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56
drivers/ata/libata-scsi.c
View File

@ -3282,6 +3282,54 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc)
return 1;
}
/**
* ata_format_dsm_trim_descr() - SATL Write Same to DSM Trim
* @cmd: SCSI command being translated
* @num: Maximum number of entries (nominally 64).
* @sector: Starting sector
* @count: Total Range of request
*
* Rewrite the WRITE SAME descriptor to be a DSM TRIM little-endian formatted
* descriptor.
*
* Upto 64 entries of the format:
* 63:48 Range Length
* 47:0 LBA
*
* Range Length of 0 is ignored.
* LBA's should be sorted order and not overlap.
*
* NOTE: this is the same format as ADD LBA(S) TO NV CACHE PINNED SET
*/
static unsigned int ata_format_dsm_trim_descr(struct scsi_cmnd *cmd, u32 num,
u64 sector, u32 count)
{
__le64 *buffer;
u32 i = 0, used_bytes;
unsigned long flags;
BUILD_BUG_ON(512 > ATA_SCSI_RBUF_SIZE);
spin_lock_irqsave(&ata_scsi_rbuf_lock, flags);
buffer = ((void *)ata_scsi_rbuf);
while (i < num) {
u64 entry = sector |
((u64)(count > 0xffff ? 0xffff : count) << 48);
buffer[i++] = __cpu_to_le64(entry);
if (count <= 0xffff)
break;
count -= 0xffff;
sector += 0xffff;
}
used_bytes = ALIGN(i * 8, 512);
memset(buffer + i, 0, used_bytes - i * 8);
sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), buffer, 512);
spin_unlock_irqrestore(&ata_scsi_rbuf_lock, flags);
return used_bytes;
}
static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc)
{
struct ata_taskfile *tf = &qc->tf;
@ -3290,8 +3338,8 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc)
const u8 *cdb = scmd->cmnd;
u64 block;
u32 n_block;
const u32 trmax = ATA_MAX_TRIM_RNUM;
u32 size;
void *buf;
u16 fp;
u8 bp = 0xff;
@ -3319,10 +3367,8 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc)
if (!scsi_sg_count(scmd))
goto invalid_param_len;
buf = page_address(sg_page(scsi_sglist(scmd)));
if (n_block <= 65535 * ATA_MAX_TRIM_RNUM) {
size = ata_set_lba_range_entries(buf, ATA_MAX_TRIM_RNUM, block, n_block);
if (n_block <= 0xffff * trmax) {
size = ata_format_dsm_trim_descr(scmd, trmax, block, n_block);
} else {
fp = 2;
goto invalid_fld;

26
include/linux/ata.h
View File

@ -1071,32 +1071,6 @@ static inline void ata_id_to_hd_driveid(u16 *id)
#endif
}
/*
* Write LBA Range Entries to the buffer that will cover the extent from
* sector to sector + count. This is used for TRIM and for ADD LBA(S)
* TO NV CACHE PINNED SET.
*/
static inline unsigned ata_set_lba_range_entries(void *_buffer,
unsigned num, u64 sector, unsigned long count)
{
__le64 *buffer = _buffer;
unsigned i = 0, used_bytes;
while (i < num) {
u64 entry = sector |
((u64)(count > 0xffff ? 0xffff : count) << 48);
buffer[i++] = __cpu_to_le64(entry);
if (count <= 0xffff)
break;
count -= 0xffff;
sector += 0xffff;
}
used_bytes = ALIGN(i * 8, 512);
memset(buffer + i, 0, used_bytes - i * 8);
return used_bytes;
}
static inline bool ata_ok(u8 status)
{
return ((status & (ATA_BUSY | ATA_DRDY | ATA_DF | ATA_DRQ | ATA_ERR))