On 8/19/19 2:46 PM, Denis V. Lunev wrote: > On 8/17/19 5:56 PM, Eric Blake wrote: >> On 8/17/19 9:49 AM, Eric Blake wrote: >> >>>> This change is a regression of sorts. Now, you are unconditionally >>>> attempting the fallback for ALL failures (such as EIO) and for all >>>> drivers, even when that was not previously attempted and increases the >>>> traffic. I think we should revert this patch and instead fix the >>>> fallocate() path to convert whatever ACTUAL errno you got from unaligned >>>> fallocate failure into ENOTSUP (that is, just the file-posix.c location >>>> that failed), while leaving all other errors as immediately fatal. >> Or even better, fix the call site of fallocate() to skip attempting an >> unaligned fallocate(), and just directly return ENOTSUP, rather than >> trying to diagnose EINVAL after the fact. >> > No way. Single ENOTSUP will turn off fallocate() support on caller side > while > aligned (99.99% of calls) works normally.
I didn't mean skip fallocate() unconditionally, only when unaligned: if (request not aligned enough) return -ENOTSUP; fallocate() ... so that the 99.99% requests that ARE aligned get to use fallocate() normally. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org
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