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) { + 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: