Date: Wed, 23 Feb 2011 14:32:38 -0500 From: John Baldwin <jhb@freebsd.org> To: gnehzuil gnehzuil <gnehzuil@gmail.com> Cc: "Pedro F. Giffuni" <giffunip@yahoo.com>, fs@freebsd.org Subject: Re: Simple ext2fs allocation routine cleanups Message-ID: <201102231432.38902.jhb@freebsd.org> In-Reply-To: <AANLkTinrMSSCrwuAtzrgNOjpV=5OpH68zOY2Lkingc7R@mail.gmail.com> References: <201102230811.32864.jhb@freebsd.org> <AANLkTinrMSSCrwuAtzrgNOjpV=5OpH68zOY2Lkingc7R@mail.gmail.com>
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On Wednesday, February 23, 2011 11:35:33 am gnehzuil gnehzuil wrote:
> Hi John,
>
> I use dbench program to do some tests for your changes. However, it causes
> kernel crash. The error is as follows:
>
> panic: __lockmgr_args: recursing on non recursive lockmgr ext2fs @
> /usr/src/sys/kern/vfs_subr.c:2124
I wasn't able to reproduce that, but I did have silly off-by-one bugs in the
use of ffs() that should be fixed now:
Index: ext2_alloc.c
===================================================================
--- ext2_alloc.c (revision 218975)
+++ ext2_alloc.c (working copy)
@@ -815,16 +815,12 @@ ext2_nodealloccg(struct inode *ip, int cg, daddr_t
}
}
i = start + len - loc;
- map = ibp[i];
- ipref = i * NBBY;
- for (i = 1; i < (1 << NBBY); i <<= 1, ipref++) {
- if ((map & i) == 0) {
- goto gotit;
- }
+ map = ibp[i] ^ 0xff;
+ if (map == 0) {
+ printf("fs = %s\n", fs->e2fs_fsmnt);
+ panic("ext2fs_nodealloccg: block not in map");
}
- printf("fs = %s\n", fs->e2fs_fsmnt);
- panic("ext2fs_nodealloccg: block not in map");
- /* NOTREACHED */
+ ipref = i * NBBY + ffs(map) - 1;
gotit:
setbit(ibp, ipref);
EXT2_LOCK(ump);
@@ -952,7 +948,6 @@ ext2_vfree(pvp, ino, mode)
static daddr_t
ext2_mapsearch(struct m_ext2fs *fs, char *bbp, daddr_t bpref)
{
- daddr_t bno;
int start, len, loc, i, map;
/*
@@ -977,15 +972,12 @@ ext2_mapsearch(struct m_ext2fs *fs, char *bbp, dad
}
}
i = start + len - loc;
- map = bbp[i];
- bno = i * NBBY;
- for (i = 1; i < (1 << NBBY); i <<= 1, bno++) {
- if ((map & i) == 0)
- return (bno);
+ map = bbp[i] ^ 0xff;
+ if (map == 0) {
+ printf("fs = %s\n", fs->e2fs_fsmnt);
+ panic("ext2fs_mapsearch: block not in map");
}
- printf("fs = %s\n", fs->e2fs_fsmnt);
- panic("ext2fs_mapsearch: block not in map");
- /* NOTREACHED */
+ return (i * NBBY + ffs(map) - 1);
}
/*
--
John Baldwin
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