Re: misc I/O submission cleanups

[Qian Cai]

On Mon, 2020-10-05 at 10:41 +0200, Christoph Hellwig wrote:
> Hi Martin,
> 
> this series tidies up various loose ends in the SCSI I/O submission path.

Reverting this patchset on the top of today's linux-next fixed the boot failures
below with libata, i.e.,

git revert --no-edit 653eb7c99d84..ed7fb2d018fd

== Easy to reproduce using qemu-kvm "-hda" CONFIG_ATA_PIIX=y. ==
.config: https://gitlab.com/cailca/linux-mm/-/blob/master/x86.config

[   46.047499][  T757] ata2.00: WARNING: zero len r/w req
[   46.049734][  T644] ata2.00: WARNING: zero len r/w req
[   46.051962][  T757] ata2.00: WARNING: zero len r/w req
[   46.054182][  T644] ata2.00: WARNING: zero len r/w req
[   46.058018][  T757] ata2.00: WARNING: zero len r/w req
[   46.060514][  T644] ata2.00: WARNING: zero len r/w req
[   46.065764][  T757] ata2.00: WARNING: zero len r/w req
[   46.068005][  T644] ata2.00: WARNING: zero len r/w req
[   46.070192][  T644] ata2.00: WARNING: zero len r/w req
[   46.072379][  T644] ata2.00: WARNING: zero len r/w req
[   46.074629][  T644] ata2.00: WARNING: zero len r/w req
[   46.077255][  T644] ata2.00: WARNING: zero len r/w req
[   46.081553][   C36] sr 1:0:0:0: [sr0] tag#0 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=0x00 cmd_age=0s
[   46.086336][   C36] sr 1:0:0:0: [sr0] tag#0 CDB: opcode=0x28 
[   46.089171][   C36] blk_update_request: I/O error, dev sr0, sector 2097136 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
[   46.094979][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer
[   46.097526][  T757] blk_update_request: I/O error, dev sr0, sector 2097136 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[   46.102364][  T757] Buffer I/O error on dev sr0, logical block 2097136, async page read
[   46.106080][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer
[   46.108590][  T757] blk_update_request: I/O error, dev sr0, sector 2097137 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[   46.113234][  T757] Buffer I/O error on dev sr0, logical block 2097137, async page read
[   46.117053][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer
[   46.119581][  T757] blk_update_request: I/O error, dev sr0, sector 2097138 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[   46.124382][  T757] Buffer I/O error on dev sr0, logical block 2097138, async page read
[   46.128545][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer
[   46.131038][  T757] blk_update_request: I/O error, dev sr0, sector 2097139 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[   46.135905][  T757] Buffer I/O error on dev sr0, logical block 2097139, async page read
[   46.139835][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer
[   46.142422][  T757] blk_update_request: I/O error, dev sr0, sector 2097140 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[   46.147240][  T757] Buffer I/O error on dev sr0, logical block 2097140, async page read
[   46.150764][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer
[   46.153248][  T757] blk_update_request: I/O error, dev sr0, sector 2097141 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[   46.158439][  T757] Buffer I/O error on dev sr0, logical block 2097141, async page read
[   46.162383][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer
[   46.165062][  T757] blk_update_request: I/O error, dev sr0, sector 2097142 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[   46.169785][  T757] Buffer I/O error on dev sr0, logical block 2097142, async page read
[   46.173252][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer
[   46.175968][  T757] blk_update_request: I/O error, dev sr0, sector 2097143 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[   46.181049][  T757] Buffer I/O error on dev sr0, logical block 2097143, async page read
[   46.184779][   C36] sr 1:0:0:0: [sr0] tag#0 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=0x00 cmd_age=0s
[   46.188966][   C36] sr 1:0:0:0: [sr0] tag#0 CDB: opcode=0x28 
[   46.191731][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer
[   46.194223][  T757] Buffer I/O error on dev sr0, logical block 0, async page read
[   46.197976][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer
[   46.200781][  T757] Buffer I/O error on dev sr0, logical block 1, async page read
[   46.204221][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer
[   46.207133][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer
[   46.209790][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer
[   46.212464][  T757] sr 1:0:0:0: [sr0] tag#0 unaligned transfer

== baremetal with ahci ==
[   14.560235][  T515] ata1.00: WARNING: zero len r/w req
[   14.560397][  T515] ata1.00: WARNING: zero len r/w req
[   14.560450][  T515] ata1.00: WARNING: zero len r/w req
[   14.560502][  T515] ata1.00: WARNING: zero len r/w req
[   14.560594][  T515] ata1.00: WARNING: zero len r/w req
[   14.560644][  T515] ata1.00: WARNING: zero len r/w req
[   14.560709][  C100] sd 0:0:0:0: [sdb] tag#7 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=0x00 cmd_age=0s
[   14.560790][  C100] sd 0:0:0:0: [sdb] tag#7 CDB: opcode=0x35 35 00 00 00 00 00 00 00 00 00
[   14.560869][  C100] blk_update_request: I/O error, dev sdb, sector 0 op 0x1:(WRITE) flags 0x800 phys_seg 0 prio class 0
[   14.562124][ T1274] ata1.00: WARNING: zero len r/w req
[   14.562172][ T1274] ata1.00: WARNING: zero len r/w req
[   14.562217][ T1274] ata1.00: WARNING: zero len r/w req
[   14.562262][ T1274] ata1.00: WARNING: zero len r/w req
[   14.562317][ T1274] ata1.00: WARNING: zero len r/w req
[   14.562361][ T1274] ata1.00: WARNING: zero len r/w req
[   14.562412][  C100] sd 0:0:0:0: [sdb] tag#8 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=0x00 cmd_age=0s
[   14.562465][  C100] sd 0:0:0:0: [sdb] tag#8 CDB: opcode=0x35 35 00 00 00 00 00 00 00 00 00
[   14.562517][  C100] blk_update_request: I/O error, dev sdb, sector 1880188816 op 0x1:(WRITE) flags 0x9800 phys_seg 1 prio class 0