From: akpm@osdl.org Subject: + ext4-balloc-fix-_with_rsv-freeze.patch added to -mm tree Date: Wed, 29 Nov 2006 14:17:10 -0800 Message-ID: <200611292217.kATMHAcU013215@shell0.pdx.osdl.net> Cc: hugh@veritas.com, cmm@us.ibm.com, linux-ext4@vger.kernel.org Return-path: Received: from smtp.osdl.org ([65.172.181.25]:31175 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1758303AbWK2W1j (ORCPT ); Wed, 29 Nov 2006 17:27:39 -0500 To: mm-commits@vger.kernel.org Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org The patch titled ext4 balloc: fix _with_rsv freeze has been added to the -mm tree. Its filename is ext4-balloc-fix-_with_rsv-freeze.patch See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this ------------------------------------------------------ Subject: ext4 balloc: fix _with_rsv freeze From: Hugh Dickins After several days of testing ext4 with reservations, it got caught inside ext4_try_to_allocate_with_rsv: alloc_new_reservation repeatedly succeeding on the window [12cff,12d0e], ext4_try_to_allocate repeatedly failing to find the free block guaranteed to be included (unless there's contention). Fix the range to find_next_usable_block's memscan: the scan from "here" (0xcfe) up to (but excluding) "maxblocks" (0xd0e) needs to scan 3 bytes not 2 (the relevant bytes of bitmap in this case being f7 df ff - none 00, but the premature cutoff implying that the last was found 00). Is this a problem for mainline ext4? No, because the "size" in its memscan is always EXT2_BLOCKS_PER_GROUP(sb), which mkfs.ext4 requires to be a multiple of 8. Is this a problem for ext3 or ext4? No, because they have an additional extN_test_allocatable test which rescues them from the error. Sync up a reservation fix from ext4 in ext4 Signed-off-by: Mingming Cao Signed-off-by: Hugh Dickins Cc: Signed-off-by: Andrew Morton --- fs/ext4/balloc.c | 2 +- 1 files changed, 1 insertion(+), 1 deletion(-) diff -puN fs/ext4/balloc.c~ext4-balloc-fix-_with_rsv-freeze fs/ext4/balloc.c --- a/fs/ext4/balloc.c~ext4-balloc-fix-_with_rsv-freeze +++ a/fs/ext4/balloc.c @@ -747,7 +747,7 @@ find_next_usable_block(ext4_grpblk_t sta here = 0; p = ((char *)bh->b_data) + (here >> 3); - r = memscan(p, 0, (maxblocks - here + 7) >> 3); + r = memscan(p, 0, ((maxblocks + 7) >> 3 - (here >> 3)); next = (r - ((char *)bh->b_data)) << 3; if (next < maxblocks && next >= start && ext4_test_allocatable(next, bh)) _ Patches currently in -mm which might be from hugh@veritas.com are git-powerpc.patch __unmap_hugepage_range-add-comment.patch shared-page-table-for-hugetlb-page-v4.patch htlb-forget-rss-with-pt-sharing.patch mlock-cleanup.patch always-print-out-the-header-line-in-proc-swaps.patch reject-corrupt-swapfiles-earlier.patch kill-install_file_ptes-pte_val.patch honour-mnt_noexec-for-access.patch ext3-fix-reservation-extension.patch ext4-fix-reservation-extension.patch ext4-balloc-reset-windowsz-when-full.patch ext4-balloc-fix-off-by-one-against-grp_goal.patch ext4-balloc-fix-off-by-one-against-rsv_end.patch ext4-balloc-say-rb_entry-not-list_entry.patch ext4-balloc-use-io_error-label.patch ext4-balloc-fix-_with_rsv-freeze.patch ext3-balloc-reset-windowsz-when-full.patch ext3-balloc-fix-off-by-one-against-grp_goal.patch ext3-balloc-fix-off-by-one-against-rsv_end.patch ext3-balloc-say-rb_entry-not-list_entry.patch ext3-balloc-use-io_error-label.patch ext3-balloc-fix-_with_rsv-freeze.patch ext2-reservations.patch ext2-balloc-fix-_with_rsv-freeze.patch ext2-balloc-reset-windowsz-when-full.patch ext2-balloc-fix-off-by-one-against-rsv_end.patch ext2-balloc-fix-off-by-one-against-grp_goal.patch ext2-balloc-say-rb_entry-not-list_entry.patch ext2-balloc-use-io_error-label.patch generic-bug-implementation.patch generic-bug-implementation-handle-bug=n.patch generic-bug-for-i386.patch generic-bug-for-x86-64.patch bug-test-1.patch tty-switch-to-ktermios-powerpc-fix.patch