hi,
> On Thu, Nov 11, 2010 at 02:10:00PM +0000, YAMAMOTO Takashi wrote:
>> hi,
>>
>> > Module Name: src
>> > Committed By: rmind
>> > Date: Wed Oct 27 02:58:05 UTC 2010
>> >
>> > Modified Files:
>> > src/sys/kern: sys_descrip.c
>> >
>> > Log Message:
>> > do_posix_fadvise: check for a negative length; truncate the offset and
>> > round the end-offset, not vice-versa.
>>
>> the latter part seems incorrect and makes putpages panic.
>> note that round_page(INT64_MAX) is negative.
>>
>> how about the attached patch?
>>
>> YAMAMOTO Takashi
>>
>> >
>> > Thanks to jakllsch@ for debug info.
>> >
>> >
>> > To generate a diff of this commit:
>> > cvs rdiff -u -r1.17 -r1.18 src/sys/kern/sys_descrip.c
>> >
>> > Please note that diffs are not public domain; they are subject to the
>> > copyright notices on the relevant files.
>
>> Index: sys_descrip.c
>> ===================================================================
>> RCS file: /cvsroot/src/sys/kern/sys_descrip.c,v
>> retrieving revision 1.18
>> diff -u -p -r1.18 sys_descrip.c
>> --- sys_descrip.c 27 Oct 2010 02:58:04 -0000 1.18
>> +++ sys_descrip.c 11 Nov 2010 14:06:40 -0000
>> @@ -680,9 +680,21 @@ do_posix_fadvise(int fd, off_t offset, o
>>
>> case POSIX_FADV_DONTNEED:
>> vp = fp->f_data;
>> - mutex_enter(&vp->v_interlock);
>> - error = VOP_PUTPAGES(vp, trunc_page(offset),
>> - round_page(endoffset), PGO_DEACTIVATE | PGO_CLEANIT);
>> + /*
>> + * align the region to page boundaries as VOP_PUTPAGES expects
>> + * by shrinking it. we shrink instead of expand because we
>> + * don't want to deactivate cache outside of the requested
>> + * region. it means that, if the specified region is smaller
>> + * than PAGE_SIZE, we do nothing.
>> + */
>> + if (endoffset - offset >= PAGE_SIZE) {
>
> What is the intended requirement of round_page(offset) and
> trunc_page(endoffset) at this point?
round_page(offset) < trunc_page(endoffset)
YAMAMOTO Takashi
>
>> + mutex_enter(&vp->v_interlock);
>> + error = VOP_PUTPAGES(vp, round_page(offset),
>> + trunc_page(endoffset),
>> + PGO_DEACTIVATE | PGO_CLEANIT);
>> + } else {
>> + error = 0;
>> + }
>> break;
>>
>> case POSIX_FADV_NOREUSE:
