freebsd-dev/sys/ufs/ffs/ffs_extern.h
Kirk McKusick fb14e73cb4 Normally when an attempt is made to mount a UFS/FFS filesystem whose
superblock has a check-hash error, an error message noting the
superblock check-hash failure is printed and the mount fails. The
administrator then runs fsck to repair the filesystem and when
successful, the filesystem can once again be mounted.

This approach fails if the filesystem in question is a root filesystem
from which you are trying to boot. Here, the loader fails when trying
to access the filesystem to get the kernel to boot. So it is necessary
to allow the loader to ignore the superblock check-hash error and make
a best effort to read the kernel. The filesystem may be suffiently
corrupted that the read attempt fails, but there is no harm in trying
since the loader makes no attempt to write to the filesystem.

Once the kernel is loaded and starts to run, it attempts to mount its
root filesystem. Once again, failure means that it breaks to its prompt
to ask where to get its root filesystem. Unless you have an alternate
root filesystem, you are stuck.

Since the root filesystem is initially mounted read-only, it is
safe to make an attempt to mount the root filesystem with the failed
superblock check-hash. Thus, when asked to mount a root filesystem
with a failed superblock check-hash, the kernel prints a warning
message that the root filesystem superblock check-hash needs repair,
but notes that it is ignoring the error and proceeding. It does
mark the filesystem as needing an fsck which prevents it from being
enabled for writing until fsck has been run on it. The net effect
is that the reboot fails to single user, but at least at that point
the administrator has the tools at hand to fix the problem.

Reported by:    Rick Macklem (rmacklem@)
Discussed with: Warner Losh (imp@)
Sponsored by:   Netflix
2018-12-06 00:09:39 +00:00

233 lines
9.0 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1991, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ffs_extern.h 8.6 (Berkeley) 3/30/95
* $FreeBSD$
*/
#ifndef _UFS_FFS_EXTERN_H
#define _UFS_FFS_EXTERN_H
#ifndef _KERNEL
#error "No user-serving parts inside"
#else
struct buf;
struct cg;
struct fid;
struct fs;
struct inode;
struct malloc_type;
struct mount;
struct thread;
struct sockaddr;
struct statfs;
struct ucred;
struct vnode;
struct vop_fsync_args;
struct vop_reallocblks_args;
struct workhead;
int ffs_alloc(struct inode *, ufs2_daddr_t, ufs2_daddr_t, int, int,
struct ucred *, ufs2_daddr_t *);
int ffs_balloc_ufs1(struct vnode *a_vp, off_t a_startoffset, int a_size,
struct ucred *a_cred, int a_flags, struct buf **a_bpp);
int ffs_balloc_ufs2(struct vnode *a_vp, off_t a_startoffset, int a_size,
struct ucred *a_cred, int a_flags, struct buf **a_bpp);
int ffs_blkatoff(struct vnode *, off_t, char **, struct buf **);
void ffs_blkfree(struct ufsmount *, struct fs *, struct vnode *,
ufs2_daddr_t, long, ino_t, enum vtype, struct workhead *, u_long);
ufs2_daddr_t ffs_blkpref_ufs1(struct inode *, ufs_lbn_t, int, ufs1_daddr_t *);
ufs2_daddr_t ffs_blkpref_ufs2(struct inode *, ufs_lbn_t, int, ufs2_daddr_t *);
void ffs_blkrelease_finish(struct ufsmount *, u_long);
u_long ffs_blkrelease_start(struct ufsmount *, struct vnode *, ino_t);
uint32_t ffs_calc_sbhash(struct fs *);
int ffs_checkfreefile(struct fs *, struct vnode *, ino_t);
void ffs_clrblock(struct fs *, u_char *, ufs1_daddr_t);
void ffs_clusteracct(struct fs *, struct cg *, ufs1_daddr_t, int);
void ffs_bdflush(struct bufobj *, struct buf *);
int ffs_copyonwrite(struct vnode *, struct buf *);
int ffs_flushfiles(struct mount *, int, struct thread *);
void ffs_fragacct(struct fs *, int, int32_t [], int);
int ffs_freefile(struct ufsmount *, struct fs *, struct vnode *, ino_t,
int, struct workhead *);
void ffs_fserr(struct fs *, ino_t, char *);
int ffs_getcg(struct fs *, struct vnode *, u_int, struct buf **,
struct cg **);
int ffs_isblock(struct fs *, u_char *, ufs1_daddr_t);
int ffs_isfreeblock(struct fs *, u_char *, ufs1_daddr_t);
int ffs_load_inode(struct buf *, struct inode *, struct fs *, ino_t);
void ffs_oldfscompat_write(struct fs *, struct ufsmount *);
int ffs_own_mount(const struct mount *mp);
int ffs_reallocblks(struct vop_reallocblks_args *);
int ffs_realloccg(struct inode *, ufs2_daddr_t, ufs2_daddr_t,
ufs2_daddr_t, int, int, int, struct ucred *, struct buf **);
int ffs_reload(struct mount *, struct thread *, int);
int ffs_sbget(void *, struct fs **, off_t, struct malloc_type *,
int (*)(void *, off_t, void **, int));
int ffs_sbput(void *, struct fs *, off_t, int (*)(void *, off_t, void *,
int));
int ffs_sbupdate(struct ufsmount *, int, int);
void ffs_setblock(struct fs *, u_char *, ufs1_daddr_t);
int ffs_snapblkfree(struct fs *, struct vnode *, ufs2_daddr_t, long, ino_t,
enum vtype, struct workhead *);
void ffs_snapremove(struct vnode *vp);
int ffs_snapshot(struct mount *mp, char *snapfile);
void ffs_snapshot_mount(struct mount *mp);
void ffs_snapshot_unmount(struct mount *mp);
void ffs_susp_initialize(void);
void ffs_susp_uninitialize(void);
void ffs_sync_snap(struct mount *, int);
int ffs_syncvnode(struct vnode *vp, int waitfor, int flags);
int ffs_truncate(struct vnode *, off_t, int, struct ucred *);
int ffs_update(struct vnode *, int);
int ffs_valloc(struct vnode *, int, struct ucred *, struct vnode **);
int ffs_vfree(struct vnode *, ino_t, int);
vfs_vget_t ffs_vget;
int ffs_vgetf(struct mount *, ino_t, int, struct vnode **, int);
void process_deferred_inactive(struct mount *mp);
/*
* Flags to ffs_vgetf
*/
#define FFSV_FORCEINSMQ 0x0001
/*
* Flags to ffs_reload
*/
#define FFSR_FORCE 0x0001
#define FFSR_UNSUSPEND 0x0002
/*
* Request standard superblock location in ffs_sbget
*/
#define STDSB -1 /* Fail if check-hash is bad */
#define STDSB_NOHASHFAIL -2 /* Ignore check-hash failure */
/*
* Definitions for TRIM interface
*
* Special keys and recommended hash table size
*/
#define NOTRIM_KEY 1 /* never written, so don't call trim for it */
#define SINGLETON_KEY 2 /* only block being freed, so trim it now */
#define FIRST_VALID_KEY 3 /* first valid key describing a block range */
#define MAXTRIMIO 1024 /* maximum expected outstanding trim requests */
extern struct vop_vector ffs_vnodeops1;
extern struct vop_vector ffs_fifoops1;
extern struct vop_vector ffs_vnodeops2;
extern struct vop_vector ffs_fifoops2;
/*
* Soft update function prototypes.
*/
int softdep_check_suspend(struct mount *, struct vnode *,
int, int, int, int);
void softdep_get_depcounts(struct mount *, int *, int *);
void softdep_initialize(void);
void softdep_uninitialize(void);
int softdep_mount(struct vnode *, struct mount *, struct fs *,
struct ucred *);
void softdep_unmount(struct mount *);
int softdep_move_dependencies(struct buf *, struct buf *);
int softdep_flushworklist(struct mount *, int *, struct thread *);
int softdep_flushfiles(struct mount *, int, struct thread *);
void softdep_update_inodeblock(struct inode *, struct buf *, int);
void softdep_load_inodeblock(struct inode *);
void softdep_freefile(struct vnode *, ino_t, int);
int softdep_request_cleanup(struct fs *, struct vnode *,
struct ucred *, int);
void softdep_setup_freeblocks(struct inode *, off_t, int);
void softdep_setup_inomapdep(struct buf *, struct inode *, ino_t, int);
void softdep_setup_blkmapdep(struct buf *, struct mount *, ufs2_daddr_t,
int, int);
void softdep_setup_allocdirect(struct inode *, ufs_lbn_t, ufs2_daddr_t,
ufs2_daddr_t, long, long, struct buf *);
void softdep_setup_allocext(struct inode *, ufs_lbn_t, ufs2_daddr_t,
ufs2_daddr_t, long, long, struct buf *);
void softdep_setup_allocindir_meta(struct buf *, struct inode *,
struct buf *, int, ufs2_daddr_t);
void softdep_setup_allocindir_page(struct inode *, ufs_lbn_t,
struct buf *, int, ufs2_daddr_t, ufs2_daddr_t, struct buf *);
void softdep_setup_blkfree(struct mount *, struct buf *, ufs2_daddr_t, int,
struct workhead *);
void softdep_setup_inofree(struct mount *, struct buf *, ino_t,
struct workhead *);
void softdep_setup_sbupdate(struct ufsmount *, struct fs *, struct buf *);
void softdep_fsync_mountdev(struct vnode *);
int softdep_sync_metadata(struct vnode *);
int softdep_sync_buf(struct vnode *, struct buf *, int);
int softdep_fsync(struct vnode *);
int softdep_prealloc(struct vnode *, int);
int softdep_journal_lookup(struct mount *, struct vnode **);
void softdep_journal_freeblocks(struct inode *, struct ucred *, off_t, int);
void softdep_journal_fsync(struct inode *);
void softdep_buf_append(struct buf *, struct workhead *);
void softdep_inode_append(struct inode *, struct ucred *, struct workhead *);
void softdep_freework(struct workhead *);
/*
* Things to request flushing in softdep_request_cleanup()
*/
#define FLUSH_INODES 1
#define FLUSH_INODES_WAIT 2
#define FLUSH_BLOCKS 3
#define FLUSH_BLOCKS_WAIT 4
/*
* Flag to ffs_syncvnode() to request flushing of data only,
* but skip the ffs_update() on the inode itself. Used to avoid
* deadlock when flushing snapshot inodes while holding snaplk.
*/
#define NO_INO_UPDT 0x00000001
/*
* Request data sync only from ffs_syncvnode(), not touching even more
* metadata than NO_INO_UPDT.
*/
#define DATA_ONLY 0x00000002
int ffs_rdonly(struct inode *);
TAILQ_HEAD(snaphead, inode);
struct snapdata {
LIST_ENTRY(snapdata) sn_link;
struct snaphead sn_head;
daddr_t sn_listsize;
daddr_t *sn_blklist;
struct lock sn_lock;
};
#endif /* _KERNEL */
#endif /* !_UFS_FFS_EXTERN_H */