From 9379e6b8e0f995365dc6158a1463c8dab4f2c8da Mon Sep 17 00:00:00 2001 From: Shaun Tancheff Date: Sun, 21 Aug 2016 23:23:18 -0500 Subject: [PATCH] libata: Safely overwrite attached page in WRITE SAME xlat Safely overwriting the attached page to ATA format from the SCSI formatted variant. Signed-off-by: Shaun Tancheff Reviewed-by: Hannes Reinecke Acked-by: Tejun Heo --- drivers/ata/libata-scsi.c | 56 +++++++++++++++++++++++++++++++++++---- include/linux/ata.h | 26 ------------------ 2 files changed, 51 insertions(+), 31 deletions(-) diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index be9c76c938b2..84e7f48ca83e 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -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; diff --git a/include/linux/ata.h b/include/linux/ata.h index adbc812c009b..45a1d71c55f1 100644 --- a/include/linux/ata.h +++ b/include/linux/ata.h @@ -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)) -- 2.20.1