(Resending with updated cover letter) These patches cleanup and improve libata support for the FUA feature of ATA devices. The first patch modifies the block layer to prevent the use of REQ_FUA with read requests. This is necessary as FUA is not supported with ATA devices when NCQ is not enabled (device queue depth set to 1) and that unlike for write requests, the flush machinery cannot enforce access to the media for FUA read commands. Patch 2 and 3 are libata cleanup preparatory patches. Patch 4 cleans up the detection for FUA support. Patch 5 fixes building a taskfile for FUA write requests. Patch 6 prevents the use of FUA with known bad drives. Finally, patch 7 enables FUA support by default in libata. Changes from v3: - Added patch 1 to prevent any block device user from issuing a REQ_FUA read. - Changed patch 5 to remove the check for REQ_FUA read and also remove support for ATA_CMD_WRITE_MULTI_FUA_EXT as this command is obsolete in recent ACS specifications. Changes from v2: - Added patch 1 and 2 as preparatory patches - Added patch 4 to fix FUA writes handling for the non-ncq case. Note that it is possible that the drives blacklisted in patch 5 are actually OK since the code back in 2012 had the issue with the wrong use of LBA 28 commands for FUA writes. Changes from v1: - Removed Maciej's patch 2. Instead, blacklist drives which are known to have a buggy FUA support. Damien Le Moal (7): block: Prevent the use of REQ_FUA with read operations ata: libata: Introduce ata_ncq_supported() ata: libata: Rename and cleanup ata_rwcmd_protocol() ata: libata: cleanup fua support detection ata: libata: Fix FUA handling in ata_build_rw_tf() ata: libata: blacklist FUA support for known buggy drives ata: libata: Enable fua support by default .../admin-guide/kernel-parameters.txt | 3 + block/blk-flush.c | 12 +++ drivers/ata/libata-core.c | 77 ++++++++++++++----- drivers/ata/libata-scsi.c | 30 +------- include/linux/libata.h | 34 +++++--- 5 files changed, 100 insertions(+), 56 deletions(-) -- 2.38.1
