Messages in this thread Patch in this message | | | Date | Tue, 30 May 2006 15:19:34 +0200 | From | Olaf Hering <> | Subject | Re: cramfs corruption after BLKFLSBUF on loop device |
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On Mon, May 29, Olaf Hering wrote:
> This script will cause cramfs decompression errors, on SMP at least: > > #!/bin/bash > while :;do blockdev --flushbufs /dev/loop0;done </dev/null &>/dev/null& > while :;do ps faxs </dev/null &>/dev/null&done </dev/null &>/dev/null& > while :;do dmesg </dev/null &>/dev/null&done </dev/null &>/dev/null& > while :;do find /mounts/instsys -type f -print0|xargs -0 cat &>/dev/null;done > > ... > Error -3 while decompressing! > c0000000009592a2(2649)->c0000000edf87000(4096) > Error -3 while decompressing! > c000000000959298(2520)->c0000000edbc7000(4096) > Error -3 while decompressing! > c000000000959c70(2489)->c0000000f1482000(4096) > Error -3 while decompressing! > c00000000095a629(2355)->c0000000edaff000(4096) > Error -3 while decompressing! > ...
This change works for me, the added BUG() does not trigger. read_cache_page() returns the page in PageUptodate() state. But a few ticks later, invalidate_complete_page() calls ClearPageUptodate(), on another cpu. The SetPageDirty() works for my testcase, but not without the mb(). Does anyone know what sideeffects the SetPageDirty() has for the loopmounted cramfs?
--- fs/cramfs/inode.c | 2 ++ fs/cramfs/uncompress.c | 1 + 2 files changed, 3 insertions(+)
Index: linux-2.6.16.16-1.6/fs/cramfs/inode.c =================================================================== --- linux-2.6.16.16-1.6.orig/fs/cramfs/inode.c +++ linux-2.6.16.16-1.6/fs/cramfs/inode.c @@ -186,6 +186,8 @@ static void *cramfs_read(struct super_bl /* synchronous error? */ if (IS_ERR(page)) page = NULL; + SetPageDirty(page); + mb(); } pages[i] = page; } Index: linux-2.6.16.16-1.6/fs/cramfs/uncompress.c =================================================================== --- linux-2.6.16.16-1.6.orig/fs/cramfs/uncompress.c +++ linux-2.6.16.16-1.6/fs/cramfs/uncompress.c @@ -50,6 +50,7 @@ int cramfs_uncompress_block(void *dst, i err: printk("Error %d while decompressing!\n", err); printk("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen); + BUG_ON(1); return 0; } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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