Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

PR/53990, PR/52380, PR/52102: UFS2 cylinder group inode allocation botch 

Fix rare allocation botch in ffs_nodealloccg().

Conditions:
   a) less than
        #_of_initialized_inodes(cg->cg_initediblk)
        - inodes_per_filesystem_block
      are allocated in the cylinder group
   b) cg->cg_irotor points to a uninterupted run of
      allocated inodes in the inode bitmap up to the
      end of dynamically initialized inodes
      (cg->cg_initediblk)

In this case the next inode after this run was returned
without initializing the respective inode block. As the
block is not initialized these inodes could trigger panics
on inode consistency due to old (uninitialized) disk data.

In very rare cases data loss could occur when
the uninitialized inode block is initialized via the
normal mechanism.
Further conditions to occur after the above:
   c) no panic
   d) no (forced) fsck
   e) and more than cg->cg_initediblk - inodes_per_filesystem_block
      allocated inodes.

Fix:
Always insure allocation always in initialized inode range
extending the initialized inode range as needed.

Add KASSERTMSG() safeguards.

ok hannken@
This commit is contained in:
kardel 2019-04-14 15:55:24 +00:00
parent 7757535d97
commit a924db8894
1 changed files with 35 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
sys/ufs/ffs/ffs_alloc.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: ffs_alloc.c,v 1.163 2018/12/10 20:48:34 jdolecek Exp $ */
/* $NetBSD: ffs_alloc.c,v 1.164 2019/04/14 15:55:24 kardel Exp $ */
/*-
* Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@ -70,7 +70,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ffs_alloc.c,v 1.163 2018/12/10 20:48:34 jdolecek Exp $");
__KERNEL_RCSID(0, "$NetBSD: ffs_alloc.c,v 1.164 2019/04/14 15:55:24 kardel Exp $");
#if defined(_KERNEL_OPT)
#include "opt_ffs.h"
@ -1259,7 +1259,7 @@ ffs_nodealloccg(struct inode *ip, int cg, daddr_t ipref, int mode, int realsize,
struct buf *bp, *ibp;
u_int8_t *inosused;
int error, start, len, loc, map, i;
int32_t initediblk;
int32_t initediblk, maxiblk, irotor;
daddr_t nalloc;
struct ufs2_dinode *dp2;
const int needswap = UFS_FSNEEDSWAP(fs);
@ -1271,7 +1271,13 @@ ffs_nodealloccg(struct inode *ip, int cg, daddr_t ipref, int mode, int realsize,
return (0);
mutex_exit(&ump->um_lock);
ibp = NULL;
initediblk = -1;
if (fs->fs_magic == FS_UFS2_MAGIC) {
initediblk = -1;
} else {
initediblk = fs->fs_ipg;
}
maxiblk = initediblk;
retry:
error = bread(ip->i_devvp, FFS_FSBTODB(fs, cgtod(fs, cg)),
(int)fs->fs_cgsize, B_MODIFY, &bp);
@ -1291,7 +1297,8 @@ retry:
* Check to see if we need to initialize more inodes.
*/
if (fs->fs_magic == FS_UFS2_MAGIC && ibp == NULL) {
initediblk = ufs_rw32(cgp->cg_initediblk, needswap);
initediblk = ufs_rw32(cgp->cg_initediblk, needswap);
maxiblk = initediblk;
nalloc = fs->fs_ipg - ufs_rw32(cgp->cg_cs.cs_nifree, needswap);
if (nalloc + FFS_INOPB(fs) > initediblk &&
initediblk < ufs_rw32(cgp->cg_niblk, needswap)) {
@ -1307,6 +1314,9 @@ retry:
FFS_NOBLK, fs->fs_bsize, false, &ibp);
if (error)
goto fail;
maxiblk += FFS_INOPB(fs);
goto retry;
}
}
@ -1316,14 +1326,22 @@ retry:
(fs->fs_old_flags & FS_FLAGS_UPDATED))
cgp->cg_time = ufs_rw64(time_second, needswap);
inosused = cg_inosused(cgp, needswap);
if (ipref) {
ipref %= fs->fs_ipg;
if (isclr(inosused, ipref))
/* safeguard to stay in (to be) allocated range */
if (ipref < maxiblk && isclr(inosused, ipref))
goto gotit;
}
start = ufs_rw32(cgp->cg_irotor, needswap) / NBBY;
len = howmany(fs->fs_ipg - ufs_rw32(cgp->cg_irotor, needswap),
NBBY);
irotor = ufs_rw32(cgp->cg_irotor, needswap);
KASSERTMSG(irotor < initediblk, "%s: allocation botch: cg=%d, irotor %d"
" out of bounds, initediblk=%d",
__func__, cg, irotor, initediblk);
start = irotor / NBBY;
len = howmany(maxiblk - irotor, NBBY);
loc = skpc(0xff, len, &inosused[start]);
if (loc == 0) {
len = start + 1;
@ -1341,9 +1359,17 @@ retry:
if (map == 0) {
panic("%s: block not in map: fs=%s", __func__, fs->fs_fsmnt);
}
ipref = i * NBBY + ffs(map) - 1;
cgp->cg_irotor = ufs_rw32(ipref, needswap);
gotit:
KASSERTMSG(ipref < maxiblk, "%s: allocation botch: cg=%d attempt to "
"allocate inode index %d beyond max allocated index %d"
" of %d inodes/cg",
__func__, cg, (int)ipref, maxiblk, cgp->cg_niblk);
UFS_WAPBL_REGISTER_INODE(ip->i_ump->um_mountp, cg * fs->fs_ipg + ipref,
mode);
/*