https://github.com/torvalds/linux
Revision e185934ff94466b4a449165e5f1c164a44d005f2 authored by Nicolai Stange on 07 December 2016, 21:21:33 UTC, committed by Tejun Heo on 07 December 2016, 21:29:09 UTC
SCT Write Same support had been introduced with commit 7b2030942859 ("libata: Add support for SCT Write Same") Some problems, namely excessive userspace segfaults, had been reported at http://lkml.kernel.org/r/20160908192736.GA4356@gmail.com This lead to commit 0ce1b18c42a5 ("libata: Some drives failing on SCT Write Same") which strived to disable SCT Write Same on !ZAC devices. Due to the way this was done and to the logic in sd_config_write_same(), this didn't work for those devices that have ->max_ws_blocks > SD_MAX_WS10_BLOCKS: for these, ->no_write_same and ->max_write_same_sectors would still be non-zero, but ->ws10 == ->ws16 == 0. This would cause sd_setup_write_same_cmnd() to demultiplex REQ_OP_WRITE_SAME requests to WRITE_SAME, and these in turn aren't supported by libata-scsi: EXT4-fs (dm-1): Delayed block allocation failed for inode 2625094 at logical offset 2032 with max blocks 2 with error 121 EXT4-fs (dm-1): This should not happen!! Data will be lost 121 == EREMOTEIO is what scsi_io_completion() asserts in case of invalid opcodes. Back to the original problem of userspace segfaults: this can be tracked down to ata_format_sct_write_same() overwriting the input page. Sometimes, this page is ZERO_PAGE(0) which ceases to be filled with zeros from that point on. Since ZERO_PAGE(0) is used for userspace .bss mappings, code of the following is doomed: static char *a = NULL; /* .bss */ ... if (a) *a = 'a'; This problem is not solved by disabling SCT Write Same for !ZAC devices only. It can certainly be fixed, but the final release is quite close -- so disable SCT Write Same for all ATA devices rather than introducing some SCT key buffer allocation schemes at this point. Fixes: 7b2030942859 ("libata: Add support for SCT Write Same") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
1 parent 5c3ef39
Tip revision: e185934ff94466b4a449165e5f1c164a44d005f2 authored by Nicolai Stange on 07 December 2016, 21:21:33 UTC
libata-scsi: disable SCT Write Same for the moment
libata-scsi: disable SCT Write Same for the moment
Tip revision: e185934
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arch | ||
block | ||
certs | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.cocciconfig | -rw-r--r-- | 59 bytes |
.get_maintainer.ignore | -rw-r--r-- | 31 bytes |
.gitattributes | -rw-r--r-- | 30 bytes |
.gitignore | -rw-r--r-- | 1.3 KB |
.mailmap | -rw-r--r-- | 7.5 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 95.9 KB |
Kbuild | -rw-r--r-- | 2.8 KB |
Kconfig | -rw-r--r-- | 252 bytes |
MAINTAINERS | -rw-r--r-- | 372.4 KB |
Makefile | -rw-r--r-- | 57.3 KB |
README | -rw-r--r-- | 17.9 KB |
REPORTING-BUGS | -rw-r--r-- | 7.3 KB |
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