4.t

早期freebsd实现

.sp
.LP
.B "BAD RETURN STATE \fIS\fP FROM DESCEND"
.br
An internal error has caused an impossible state \fIS\fP to be returned
from the routine that descends the file system directory structure.
.I Fsck
exits.
See a guru.
.sp
.LP
.B "BAD STATE \fIS\fP FOR ROOT INODE"
.br
An internal error has caused an impossible state \fIS\fP to be assigned
to the root inode.
.I Fsck
exits.
See a guru.
.NH 2 
Phase 3 \- Check Connectivity
.PP
This phase concerns itself with the directory connectivity seen in
Phase 2.
This section lists error conditions resulting from
unreferenced directories,
and missing or full
.I lost+found
directories.
.sp
.LP
.B "UNREF DIR I=\fII\fP OWNER=\fIO\fP MODE=\fIM\fP SIZE=\fIS\fP MTIME=\fIT\fP (RECONNECT)"
.br
The directory inode \fII\fP was not connected to a directory entry
when the file system was traversed.
The owner \fIO\fP, mode \fIM\fP, size \fIS\fP, and
modify time \fIT\fP of directory inode \fII\fP are printed.
When preen'ing, the directory is reconnected if its size is non-zero,
otherwise it is cleared.
.LP
Possible responses to the RECONNECT prompt are:
.IP YES
reconnect directory inode \fII\fP to the file system in the
directory for lost files (usually \fIlost+found\fP).
This may invoke the
.I lost+found
error condition in Phase 3
if there are problems connecting directory inode \fII\fP to \fIlost+found\fP.
This may also invoke the CONNECTED error condition in Phase 3 if the link
was successful.
.IP NO
ignore this error condition.
This will always invoke the UNREF error condition in Phase 4.
.sp
.LP
.B "NO lost+found DIRECTORY (CREATE)"
.br
There is no
.I lost+found
directory in the root directory of the file system;
When preen'ing
.I fsck
tries to create a \fIlost+found\fP directory.
.LP
Possible responses to the CREATE prompt are:
.IP YES
create a \fIlost+found\fP directory in the root of the file system.
This may raise the message:
.br
.B "NO SPACE LEFT IN / (EXPAND)"
.br
See below for the possible responses.
Inability to create a \fIlost+found\fP directory generates the message:
.br
.B "SORRY. CANNOT CREATE lost+found DIRECTORY"
.br
and aborts the attempt to linkup the lost inode.
This will always invoke the UNREF error condition in Phase 4.
.IP NO
abort the attempt to linkup the lost inode.
This will always invoke the UNREF error condition in Phase 4.
.sp
.LP
.B "lost+found IS NOT A DIRECTORY (REALLOCATE)"
.br
The entry for
.I lost+found
is not a directory.
.LP
Possible responses to the REALLOCATE prompt are:
.IP YES
allocate a directory inode, and change \fIlost+found\fP to reference it.
The previous inode reference by the \fIlost+found\fP name is not cleared.
Thus it will either be reclaimed as an UNREF'ed inode or have its
link count ADJUST'ed later in this Phase.
Inability to create a \fIlost+found\fP directory generates the message:
.br
.B "SORRY. CANNOT CREATE lost+found DIRECTORY"
.br
and aborts the attempt to linkup the lost inode.
This will always invoke the UNREF error condition in Phase 4.
.IP NO
abort the attempt to linkup the lost inode.
This will always invoke the UNREF error condition in Phase 4.
.sp
.LP
.B "NO SPACE LEFT IN /lost+found (EXPAND)"
.br
There is no space to add another entry to the
.I lost+found
directory in the root directory
of the file system.
When preen'ing the 
.I lost+found
directory is expanded.
.LP
Possible responses to the EXPAND prompt are:
.IP YES
the 
.I lost+found
directory is expanded to make room for the new entry.
If the attempted expansion fails
.I fsck
prints the message:
.br
.B "SORRY. NO SPACE IN lost+found DIRECTORY"
.br
and aborts the attempt to linkup the lost inode.
This will always invoke the UNREF error condition in Phase 4.
Clean out unnecessary entries in
.I lost+found .
This error is fatal if the file system is being preen'ed.
.IP NO
abort the attempt to linkup the lost inode.
This will always invoke the UNREF error condition in Phase 4.
.sp
.LP
.B "DIR I=\fII1\fP CONNECTED. PARENT WAS I=\fII2\fP"
.br
This is an advisory message indicating a directory inode \fII1\fP was
successfully connected to the
.I lost+found
directory.
The parent inode \fII2\fP of the directory inode \fII1\fP is
replaced by the inode number of the
.I lost+found
directory.
.sp
.LP
.B "DIRECTORY \fIF\fP LENGTH \fIS\fP NOT MULTIPLE OF \fIB\fP (ADJUST)
.br
A directory \fIF\fP has been found with size \fIS\fP that is not
a multiple of the directory blocksize \fIB\fP
(this can reoccur in Phase 3 if it is not adjusted in Phase 2).
.LP
Possible responses to the ADJUST prompt are:
.IP YES
the length is rounded up to the appropriate block size.
This error can occur on 4.2BSD file systems.
Thus when preen'ing the file system only a warning is printed
and the directory is adjusted.
.IP NO
ignore the error condition.
.sp
.LP
.B "BAD INODE \fIS\fP TO DESCEND"
.br
An internal error has caused an impossible state \fIS\fP to be passed to the
routine that descends the file system directory structure.
.I Fsck
exits.
See a guru.
.NH 2 
Phase 4 \- Check Reference Counts
.PP
This phase concerns itself with the link count information
seen in Phase 2 and Phase 3.
This section lists error conditions resulting from
unreferenced files,
missing or full
.I lost+found
directory,
incorrect link counts for files, directories, symbolic links, or special files,
unreferenced files, symbolic links, and directories,
and bad or duplicate blocks in files, symbolic links, and directories.
All errors in this phase are correctable if the file system is being preen'ed
except running out of space in the \fIlost+found\fP directory.
.sp
.LP
.B "UNREF FILE I=\fII\fP OWNER=\fIO\fP MODE=\fIM\fP SIZE=\fIS\fP MTIME=\fIT\fP (RECONNECT)"
.br
Inode \fII\fP was not connected to a directory entry
when the file system was traversed.
The owner \fIO\fP, mode \fIM\fP, size \fIS\fP, and
modify time \fIT\fP of inode \fII\fP are printed.
When preen'ing the file is cleared if either its size or its
link count is zero,
otherwise it is reconnected.
.LP
Possible responses to the RECONNECT prompt are:
.IP YES
reconnect inode \fII\fP to the file system in the directory for
lost files (usually \fIlost+found\fP).
This may invoke the
.I lost+found
error condition in Phase 4
if there are problems connecting inode \fII\fP to
.I lost+found .
.IP NO
ignore this error condition.
This will always invoke the CLEAR error condition in Phase 4.
.sp
.LP
.B "(CLEAR)"
.br
The inode mentioned in the immediately previous error condition can not be
reconnected.
This cannot occur if the file system is being preen'ed,
since lack of space to reconnect files is a fatal error.
.LP
Possible responses to the CLEAR prompt are:
.IP YES
de-allocate the inode mentioned in the immediately previous error condition by zeroing its contents.
.IP NO
ignore this error condition.
.sp
.LP
.B "NO lost+found DIRECTORY (CREATE)"
.br
There is no
.I lost+found
directory in the root directory of the file system;
When preen'ing
.I fsck
tries to create a \fIlost+found\fP directory.
.LP
Possible responses to the CREATE prompt are:
.IP YES
create a \fIlost+found\fP directory in the root of the file system.
This may raise the message:
.br
.B "NO SPACE LEFT IN / (EXPAND)"
.br
See below for the possible responses.
Inability to create a \fIlost+found\fP directory generates the message:
.br
.B "SORRY. CANNOT CREATE lost+found DIRECTORY"
.br
and aborts the attempt to linkup the lost inode.
This will always invoke the UNREF error condition in Phase 4.
.IP NO
abort the attempt to linkup the lost inode.
This will always invoke the UNREF error condition in Phase 4.
.sp
.LP
.B "lost+found IS NOT A DIRECTORY (REALLOCATE)"
.br
The entry for
.I lost+found
is not a directory.
.LP
Possible responses to the REALLOCATE prompt are:
.IP YES
allocate a directory inode, and change \fIlost+found\fP to reference it.
The previous inode reference by the \fIlost+found\fP name is not cleared.
Thus it will either be reclaimed as an UNREF'ed inode or have its
link count ADJUST'ed later in this Phase.
Inability to create a \fIlost+found\fP directory generates the message:
.br
.B "SORRY. CANNOT CREATE lost+found DIRECTORY"
.br
and aborts the attempt to linkup the lost inode.
This will always invoke the UNREF error condition in Phase 4.
.IP NO
abort the attempt to linkup the lost inode.
This will always invoke the UNREF error condition in Phase 4.
.sp
.LP
.B "NO SPACE LEFT IN /lost+found (EXPAND)"
.br
There is no space to add another entry to the
.I lost+found
directory in the root directory
of the file system.
When preen'ing the 
.I lost+found
directory is expanded.
.LP
Possible responses to the EXPAND prompt are:
.IP YES
the 
.I lost+found
directory is expanded to make room for the new entry.
If the attempted expansion fails
.I fsck
prints the message:
.br
.B "SORRY. NO SPACE IN lost+found DIRECTORY"
.br
and aborts the attempt to linkup the lost inode.
This will always invoke the UNREF error condition in Phase 4.
Clean out unnecessary entries in
.I lost+found .
This error is fatal if the file system is being preen'ed.
.IP NO
abort the attempt to linkup the lost inode.
This will always invoke the UNREF error condition in Phase 4.
.sp
.LP
.B "LINK COUNT \fItype\fP I=\fII\fP OWNER=\fIO\fP MODE=\fIM\fP SIZE=\fIS\fP MTIME=\fIT\fP COUNT=\fIX\fP SHOULD BE \fIY\fP (ADJUST)"
.br
The link count for inode \fII\fP,
is \fIX\fP but should be \fIY\fP.
The owner \fIO\fP, mode \fIM\fP, size \fIS\fP, and modify time \fIT\fP
are printed.
When preen'ing the link count is adjusted unless the number of references
is increasing, a condition that should never occur unless precipitated
by a hardware failure.
When the number of references is increasing under preen mode,
.I fsck
exits with the message:
.br
.B "LINK COUNT INCREASING"
.LP
Possible responses to the ADJUST prompt are:
.IP YES
replace the link count of file inode \fII\fP with \fIY\fP.
.IP NO
ignore this error condition.
.sp
.LP
.B "UNREF \fItype\fP I=\fII\fP OWNER=\fIO\fP MODE=\fIM\fP SIZE=\fIS\fP MTIME=\fIT\fP (CLEAR)"
.br
Inode \fII\fP, was not connected to a directory entry when the
file system was traversed.
The owner \fIO\fP, mode \fIM\fP, size \fIS\fP,
and modify time \fIT\fP of inode \fII\fP
are printed.
When preen'ing,
this is a file that was not connected because its size or link count was zero,
hence it is cleared.
.LP
Possible responses to the CLEAR prompt are:
.IP YES
de-allocate inode \fII\fP by zeroing its contents.
.IP NO
ignore this error condition.
.sp
.LP
.B "BAD/DUP \fItype\fP I=\fII\fP OWNER=\fIO\fP MODE=\fIM\fP SIZE=\fIS\fP MTIME=\fIT\fP (CLEAR)"
.br
Phase 1 or Phase 1b have found duplicate blocks
or bad blocks associated with
inode \fII\fP.
The owner \fIO\fP, mode \fIM\fP, size \fIS\fP,
and modify time \fIT\fP of inode \fII\fP
are printed.
This error cannot arise when the file system is being preen'ed,
as it would have caused a fatal error earlier.
.LP
Possible responses to the CLEAR prompt are:
.IP YES
de-allocate inode \fII\fP by zeroing its contents.
.IP NO
ignore this error condition.
.NH 2 
Phase 5 - Check Cyl groups
.PP
This phase concerns itself with the free-block and used-inode maps.
This section lists error conditions resulting from
allocated blocks in the free-block maps,
free blocks missing from free-block maps,
and the total free-block count incorrect.
It also lists error conditions resulting from
free inodes in the used-inode maps,
allocated inodes missing from used-inode maps,
and the total used-inode count incorrect.
.sp
.LP
.B "CG \fIC\fP: BAD MAGIC NUMBER"
.br
The magic number of cylinder group \fIC\fP is wrong.
This usually indicates that the cylinder group maps have been destroyed.
When running manually the cylinder group is marked as needing
to be reconstructed.
This error is fatal if the file system is being preen'ed.
.sp
.LP
.B "BLK(S) MISSING IN BIT MAPS (SALVAGE)"
.br
A cylinder group block map is missing some free blocks.
During preen'ing the maps are reconstructed.
.LP
Possible responses to the SALVAGE prompt are:
.IP YES
reconstruct the free block map.
.IP NO
ignore this error condition.
.sp
.LP
.B "SUMMARY INFORMATION BAD (SALVAGE)"
.br
The summary information was found to be incorrect.
When preen'ing,
the summary information is recomputed.
.LP
Possible responses to the SALVAGE prompt are:
.IP YES
reconstruct the summary information.
.IP NO
ignore this error condition.
.sp
.LP
.B "FREE BLK COUNT(S) WRONG IN SUPERBLOCK (SALVAGE)"
.br
The superblock free block information was found to be incorrect.
When preen'ing,
the superblock free block information is recomputed.
.LP
Possible responses to the SALVAGE prompt are:
.IP YES
reconstruct the superblock free block information.
.IP NO
ignore this error condition.
.NH 2 
Cleanup
.PP
Once a file system has been checked, a few cleanup functions are performed.
This section lists advisory messages about
the file system
and modify status of the file system.
.sp
.LP
.B "\fIV\fP files, \fIW\fP used, \fIX\fP free (\fIY\fP frags, \fIZ\fP blocks)"
.br
This is an advisory message indicating that
the file system checked contained
\fIV\fP files using
\fIW\fP fragment sized blocks leaving
\fIX\fP fragment sized blocks free in the file system.
The numbers in parenthesis breaks the free count down into
\fIY\fP free fragments and
\fIZ\fP free full sized blocks.
.sp
.LP
.B "***** REBOOT UNIX *****"
.br
This is an advisory message indicating that
the root file system has been modified by
.I fsck.
If UNIX is not rebooted immediately,
the work done by
.I fsck
may be undone by the in-core copies of tables
UNIX keeps.
When preen'ing,
.I fsck
will exit with a code of 4.
The standard auto-reboot script distributed with 4.3BSD 
interprets an exit code of 4 by issuing a reboot system call.
.sp
.LP
.B "***** FILE SYSTEM WAS MODIFIED *****"
.br
This is an advisory message indicating that
the current file system was modified by
.I fsck.
If this file system is mounted or is the current root file system,
.I fsck
should be halted and UNIX rebooted.
If UNIX is not rebooted immediately,
the work done by
.I fsck
may be undone by the in-core copies of tables
UNIX keeps.