Date: Wed, 28 May 2014 13:01:11 +0000 (UTC) From: Gleb Smirnoff <glebius@FreeBSD.org> To: src-committers@freebsd.org, svn-src-projects@freebsd.org Subject: svn commit: r266804 - projects/sendfile/sys/kern Message-ID: <201405281301.s4SD1BkA053088@svn.freebsd.org>
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Author: glebius Date: Wed May 28 13:01:10 2014 New Revision: 266804 URL: http://svnweb.freebsd.org/changeset/base/266804 Log: When working on a sparse file sendfile_getpages() could skip a page. This happened due to increment both in the for (;;) statement and in the loop itself. Fix this by removing increment in for (;;). Now all increments are done "manually", this fixes the bug and makes code more comprehendable. Sponsored by: Netflix Sponsored by: Nginx, Inc. Modified: projects/sendfile/sys/kern/uipc_syscalls.c Modified: projects/sendfile/sys/kern/uipc_syscalls.c ============================================================================== --- projects/sendfile/sys/kern/uipc_syscalls.c Wed May 28 12:58:37 2014 (r266803) +++ projects/sendfile/sys/kern/uipc_syscalls.c Wed May 28 13:01:10 2014 (r266804) @@ -2750,12 +2750,13 @@ sendfile_swapin(vm_object_t obj, struct pa[i] = vm_page_grab(obj, OFF_TO_IDX(vmoff(i, off)), VM_ALLOC_WIRED | VM_ALLOC_NORMAL); - for (int i = 0; i < npages; i++) { + for (int i = 0; i < npages;) { int j, a, count, rv; if (vm_page_is_valid(pa[i], vmoff(i, off) & PAGE_MASK, xfsize(i, npages, off, len))) { vm_page_xunbusy(pa[i]); + i++; continue; } @@ -2806,7 +2807,7 @@ sendfile_swapin(vm_object_t obj, struct ("pa[j] %p lookup %p\n", pa[j], vm_page_lookup(obj, OFF_TO_IDX(vmoff(j, off))))); - i += count - 1; + i += count; } VM_OBJECT_WUNLOCK(obj);
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