.\"
.TH DEBUGFS 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
.SH NAME
-debugfs \- ext2 file system debugger
+debugfs \- ext2/ext3 file system debugger
.SH SYNOPSIS
.B debugfs
[
+.B \-Vwci
+]
+[
.B \-b
blocksize
]
request
]
[
-.B \-V
-]
-[
-[
-.B \-w
-]
-[
-.B \-c
-]
-[
-.B \-i
+.B \-d
+data_source_device
]
[
device
]
-]
.SH DESCRIPTION
The
.B debugfs
.B debugfs
may fail in interesting ways if commands such as
.IR ls ", " dump ", "
-etc. are tried.
+etc. are tried without specifying the
+.I data_source_device
+using the
+.I \-d
+option.
.B debugfs
is a debugging tool. It has rough edges!
.TP
+.I -d data_source_device
+Used with the
+.I \-i
+option, specifies that
+.I data_source_device
+should be used when reading blocks not found in the ext2 image file.
+This includes data, directory, and indirect blocks.
+.TP
.I -b blocksize
Forces the use of the given block size for the file system, rather than
detecting the correct block size as normal.
.B debugfs
supports.
.TP
+.I bmap filespec logical_block
+Print the physical block number corresponding to the logical block number
+.I logical_block
+in the inode
+.IR filespec .
+.TP
.I cat filespec
Dump the contents of the inode
.I filespec
or clearing any filesystem features that were requested, print the current
state of the filesystem feature set.
.TP
-.I find_free_block [goal]
-Find the first free block, starting from
+.I find_free_block [count [goal]]
+Find the first
+.I count
+free blocks, starting from
.I goal
and allocate it.
.TP
specifies the permissions of the new inode. (If the directory bit is set
on the mode, the allocation routine will function differently.)
.TP
-.I freeb block
+.I freeb block [count]
Mark the block number
.I block
as not allocated.
+If the optional argument
+.I count
+is present, then
+.I count
+blocks starting at block number
+.I block
+will be marked as not allocated.
.TP
.I freei filespec
Free the inode specified by
Print a listing of the inodes which use the one or more blocks specified
on the command line.
.TP
-.I initialize device blocksize
+.I imap filespec
+Print the location of the inode data structure (in the inode table)
+of the inode
+.IR filespec .
+.TP
+.I init_filesys device blocksize
Create an ext2 file system on
.I device
with device size
.IR filespec .
Note this does not adjust the inode reference counts.
.TP
-.I logdump [-ac] [-b<block>] [-i<inode>] [-f<journal_file>] [output_file]
-Dump the contents of the ext3 journal.
-.TP
-.I ls [-l] filespec
+.I logdump [-acs] [-b<block>] [-i<filespec>] [-f<journal_file>] [output_file]
+Dump the contents of the ext3 journal. By default, the journal inode as
+specified in the superblock. However, this can be overridden with the
+.I \-i
+option, which uses an inode specifier to specify the journal to be
+used. A file containing journal data can be specified using the
+.I \-f
+option. Finally, the
+.I \-s
+option utilizes the backup information in the superblock to locate the
+journal.
+.IP
+The
+.I \-a
+option causes the
+.I logdump
+program to print the contents of all of the descriptor blocks.
+The
+.I \-b
+option causes
+.I logdump
+to print all journal records that are refer to the specified block.
+The
+.I \-c
+option will print out the contents of all of the data blocks selected by
+the
+.I \-a
+and
+.I \-b
+options.
+.TP
+.I ls [-l] [-d] filespec
Print a listing of the files in the directory
.IR filespec .
+The
+.I \-l
+flag will list files using a more verbose format.
+The
+.I \-d
+flag will list deleted entries in the directory.
.TP
.I modify_inode filespec
Modify the contents of the inode structure in the inode
Take the requested list of inode numbers, and print a listing of pathnames
to those inodes.
.TP
-.I open [-w] [-f] [-i] [-c] [-b blocksize] [-s superblock] device
+.I open [-w] [-e] [-f] [-i] [-c] [-b blocksize] [-s superblock] device
Open a filesystem for editing. The
-.I -w
-flag causes the filesystem to be opened for writing. The
.I -f
flag forces the filesystem to be opened even if there are some unknown
or incompatible filesystem features which would normally
prevent the filesystem from being opened. The
-.IR -c ", " -b ", " -i ", " and " -s
-options behave the same as those to
-.B debugfs
-itself.
+.I -e
+flag causes the filesystem to be opened in exclusive mode. The
+.IR -b ", " -c ", " -i ", " -s ", and " -w
+options behave the same as the command-line options to
+.BR debugfs .
.TP
.I pwd
Print the current working directory.
.I rmdir filespec
Remove the directory
.IR filespec .
-This function is currently not implemented.
.TP
-.I setb block
+.I setb block [count]
Mark the block number
.I block
as allocated.
+If the optional argument
+.I count
+is present, then
+.I count
+blocks starting at block number
+.I block
+will be marked as allocated.
+.TP
+.I set_block_group bgnum field value
+Modify the block group descriptor specified by
+.I bgnum
+so that the block group descriptor field
+.I field
+has value
+.I value.
.TP
.I seti filespec
Mark inode
.I filespec
as in use in the inode bitmap.
.TP
+.I set_inode_field filespec field value
+Modify the inode specified by
+.I filespec
+so that the inode field
+.I field
+has value
+.I value.
+The list of valid inode fields which can be set via this command
+can be displayed by using the command:
+.B set_inode_field -l
+.TP
.I set_super_value field value
Set the superblock field
.I field
Display the contents of the inode structure of the inode
.IR filespec .
.TP
-.I testb block
+.I testb block [count]
Test if the block number
.I block
is marked as allocated in the block bitmap.
+If the optional argument
+.I count
+is present, then
+.I count
+blocks starting at block number
+.I block
+will be tested.
.TP
.I testi filespec
Test if the inode
.I filespec
is marked as allocated in the inode bitmap.
.TP
+.I undel <inode num> [pathname]
+Undelete the specified inode number (which must be surrounded by angle
+brackets) so that it and its blocks are marked in use, and optionally
+link the recovered inode to the specified pathname. The
+.B e2fsck
+command should always be run after using the
+.B undel
+command to recover deleted files.
+.IP
+Note that if you are recovering a large number of deleted files, linking
+the inode to a directory may require the directory to be expanded, which
+could allocate a block that had been used by one of the
+yet-to-be-undeleted files. So it is safer to undelete all of the
+inodes without specifying a destination pathname, and then in a separate
+pass, use the debugfs
+.B link
+command to link the inode to the destination pathname, or use
+.B e2fsck
+to check the filesystem and link all of the recovered inodes to the
+lost+found dirctory.
+.TP
.I unlink pathname
Remove the link specified by
.I pathname
and copy the contents of
.I source_file
into the destination file.
+.SH ENVIRONMENT VARIABLES
+.TP
+.B DEBUGFS_PAGER, PAGER
+The
+.BR debugfs (8)
+program always pipes the output of the some commands through a
+pager program. These commands include:
+.IR show_super_stats ,
+.IR list_directory ,
+.IR show_inode_info ,
+.IR list_deleted_inodes ,
+and
+.IR htree_dump .
+The specific pager can explicitly specified by the
+.B DEBUGFS_PAGER
+environment variable, and if it is not set, by the
+.B PAGER
+environment variable.
+.IP
+Note that since a pager is always used, the
+.BR less (1)
+pager is not particularly appropriate, since it clears the screen before
+displaying the output of the command and clears the output the screen
+when the pager is exited. Many users prefer to use the
+.BR less (1)
+pager for most purposes, which is why the
+.B DEBUGFS_PAGER
+environment variable is available to override the more general
+.B PAGER
+environment variable.
.SH AUTHOR
.B debugfs
was written by Theodore Ts'o <tytso@mit.edu>.
.SH SEE ALSO
.BR dumpe2fs (8),
+.BR tune2fs (8),
.BR e2fsck (8),
.BR mke2fs (8)
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff