.SH SYNOPSIS
.B debugfs
[
-.B \-DVwci
+.B \-DVwcin
]
[
.B \-b
data_source_device
]
[
+.B \-z
+.I undo_file
+]
+[
device
]
.SH DESCRIPTION
.B debugfs
program is an interactive file system debugger. It can be used to
examine and change the state of an ext2, ext3, or ext4 file system.
-.br
+.PP
.I device
-is the special file corresponding to the device containing the
-file system (e.g /dev/hdXX).
+is a block device (e.g., /dev/sdXX) or a file containing the file system.
.SH OPTIONS
.TP
.I \-w
Specifies that the file system should be opened in read-write mode.
Without this option, the file system is opened in read-only mode.
.TP
+.I \-n
+Disables metadata checksum verification. This should only be used if
+you believe the metadata to be correct despite the complaints of
+e2fsprogs.
+.TP
.I \-c
Specifies that the file system should be opened in catastrophic mode, in
which the inode and group bitmaps are not read initially. This can be
-useful for filesystems with significant corruption, but because of this,
-catastrophic mode forces the filesystem to be opened read-only.
+useful for file systems with significant corruption, but because of this,
+catastrophic mode forces the file system to be opened read-only.
.TP
.I \-i
Specifies that
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.
+Forces the use of the given block size (in bytes) for the file system,
+rather than detecting the correct block size automatically. (This
+option is rarely needed; it is used primarily when the file system is
+extremely badly damaged/corrupted.)
.TP
.I -s superblock
Causes the file system superblock to be read from the given block
number, instead of using the primary superblock (located at an offset of
-1024 bytes from the beginning of the filesystem). If you specify the
+1024 bytes from the beginning of the file system). If you specify the
.I -s
-option, you must also provide the blocksize of the filesystem via the
+option, you must also provide the blocksize of the file system via the
.I -b
-option.
+option. (This
+option is rarely needed; it is used primarily when the file system is
+extremely badly damaged/corrupted.)
.TP
.I -f cmd_file
Causes
print the version number of
.B debugfs
and exit.
+.TP
+.BI \-z " undo_file"
+Before overwriting a file system block, write the old contents of the block to
+an undo file. This undo file can be used with e2undo(8) to restore the old
+contents of the file system should something go wrong. If the empty string is
+passed as the undo_file argument, the undo file will be written to a file named
+debugfs-\fIdevice\fR.e2undo in the directory specified via the
+\fIE2FSPROGS_UNDO_DIR\fR environment variable.
+
+WARNING: The undo file cannot be used to recover from a power or system crash.
.SH SPECIFYING FILES
Many
.B debugfs
commands take a
.I filespec
as an argument to specify an inode (as opposed to a pathname)
-in the filesystem which is currently opened by
+in the file system which is currently opened by
.BR debugfs .
The
.I filespec
number surrounded by angle brackets, e.g.,
.IR <2> .
The second form is a pathname; if the pathname is prefixed by a forward slash
-('/'), then it is interpreted relative to the root of the filesystem
+('/'), then it is interpreted relative to the root of the file system
which is currently opened by
.BR debugfs .
If not, the pathname is
.B debugfs
supports.
.TP
-.BI blocks " filespace"
+.BI blocks " filespec"
Print the blocks used by the inode
.I filespec
to stdout.
.TP
-.BI bmap " filespec logical_block"
-Print the physical block number corresponding to the logical block number
+.BI bmap " [ -a ] filespec logical_block [physical_block]"
+Print or set the physical block number corresponding to the logical block number
.I logical_block
in the inode
.IR filespec .
+If the
+.I \-a
+flag is specified, try to allocate a block if necessary.
.TP
-.BI block_dump " [-f filespec] block_num"
-Dump the filesystem block given by
+.BI block_dump " '[ -x ] [-f filespec] block_num"
+Dump the file system block given by
.I block_num
in hex and ASCII format to the console. If the
-.I -f
+.I \-f
option is specified, the block number is relative to the start of the given
.BR filespec .
+If the
+.I \-x
+option is specified, the block is interpreted as an extended attribute
+block and printed to show the structure of extended attribute data
+structures.
.TP
.BI cat " filespec"
Dump the contents of the inode
Clear the contents of the inode
.IR filespec .
.TP
+.BI copy_inode " source_inode destination_inode"
+Copy the contents of the inode structure in
+.I source_inode
+and use it to overwrite the inode structure at
+.IR destination_inode .
+.TP
.BI dirsearch " filespec filename"
Search the directory
.I filespec
for
.IR filename .
.TP
-.B dirty
-Mark the filesystem as dirty, so that the superblocks will be written on exit.
+.BI dirty " [-clean]"
+Mark the file system as dirty, so that the superblocks will be written on exit.
+Additionally, clear the superblock's valid flag, or set it if
+.I -clean
+is specified.
.TP
.BI dump " [-p] filespec out_file"
Dump the contents of the inode
to match
.IR filespec .
.TP
-.B dump_mmp
-Display the multiple-mount protection (mmp) field values.
+.BI dump_mmp " [mmp_block]"
+Display the multiple-mount protection (mmp) field values. If
+.I mmp_block
+is specified then verify and dump the MMP values from the given block
+number, otherwise use the
+.B s_mmp_block
+field in the superblock to locate and use the existing MMP block.
.TP
.BI dx_hash " [-h hash_alg] [-s hash_seed] filename"
Calculate the directory hash of
must be in UUID format.
.TP
.BI dump_extents " [-n] [-l] filespec"
-Dump the the extent tree of the inode
+Dump the extent tree of the inode
.IR filespec .
The
.I -n
.IP
(Please note that the length and range of blocks for the last extent in
an interior node is an estimate by the extents library functions, and is
-not stored in filesystem data structures. Hence, the values displayed
+not stored in file system data structures. Hence, the values displayed
may not necessarily by accurate and does not indicate a problem or
corruption in the file system.)
.TP
+.B dump_unused
+Dump unused blocks which contain non-null bytes.
+.TP
+.BI ea_get " [-f outfile]|[-xVC] [-r] filespec attr_name"
+Retrieve the value of the extended attribute
+.I attr_name
+in the file
+.I filespec
+and write it either to stdout or to \fIoutfile\fR.
+.TP
+.BI ea_list " filespec
+List the extended attributes associated with the file
+.I filespec
+to standard output.
+.TP
+.BI ea_set " [-f infile] [-r] filespec attr_name attr_value
+Set the value of the extended attribute
+.I attr_name
+in the file
+.I filespec
+to the string value
+.I attr_value
+or read it from \fIinfile\fR.
+.TP
+.BI ea_rm " filespec attr_names...
+Remove the extended attribute
+.I attr_name
+from the file \fIfilespec\fR.
+.TP
.BI expand_dir " filespec"
Expand the directory
.IR filespec .
.TP
+.BI fallocate " filespec start_block [end_block]
+Allocate and map uninitialized blocks into \fIfilespec\fR between
+logical block \fIstart_block\fR and \fIend_block\fR, inclusive. If
+\fIend_block\fR is not supplied, this function maps until it runs out
+of free disk blocks or the maximum file size is reached. Existing
+mappings are left alone.
+.TP
.BI feature " [fs_feature] [-fs_feature] ..."
-Set or clear various filesystem features in the superblock. After setting
-or clearing any filesystem features that were requested, print the current
-state of the filesystem feature set.
+Set or clear various file system features in the superblock. After setting
+or clearing any file system features that were requested, print the current
+state of the file system feature set.
.TP
.BI filefrag " [-dvr] filespec"
Print the number of contiguous extents in
.I num
is specified, also clear num-1 inodes after the specified inode.
.TP
+.BI get_quota " quota_type id"
+Display quota information for given quota type (user, group, or project) and ID.
+.TP
.B help
Print a list of commands understood by
.BR debugfs .
Print a listing of the inodes which use the one or more blocks specified
on the command line.
.TP
+.BI inode_dump " [-b]|[-e]|[-x] filespec"
+Print the contents of the inode data structure in hex and ASCII format.
+The
+.I \-b
+option causes the command to only dump the contents of the
+.B i_blocks
+array. The
+.I \-e
+option causes the command to only dump the contents of the extra inode
+space, which is used to store in-line extended attributes. The
+.I \-x
+option causes the command to dump the extra inode space interpreted and
+extended attributes. This is useful to debug corrupted inodes
+containing extended attributes.
+.TP
.BI imap " filespec"
Print the location of the inode data structure (in the inode table)
of the inode
program. This is just a call to the low-level library, which sets up
the superblock and block descriptors.
.TP
+.BI journal_close
+Close the open journal.
+.TP
+.BI journal_open " [-c] [-v ver] [-f ext_jnl]
+Opens the journal for reading and writing. Journal checksumming can
+be enabled by supplying \fI-c\fR; checksum formats 2 and 3 can be
+selected with the \fI-v\fR option. An external journal can be loaded
+from \fIext_jnl\fR.
+.TP
+.BI journal_run
+Replay all transactions in the open journal.
+.TP
+.BI journal_write " [-b blocks] [-r revoke] [-c] file
+Write a transaction to the open journal. The list of blocks to write
+should be supplied as a comma-separated list in \fIblocks\fR; the
+blocks themselves should be readable from \fIfile\fR. A list of
+blocks to revoke can be supplied as a comma-separated list in
+\fIrevoke\fR. By default, a commit record is written at the end; the
+\fI-c\fR switch writes an uncommitted transaction.
+.TP
.BI kill_file " filespec"
Deallocate the inode
.I filespec
.B debugfs
process to
.I directory
-on the native filesystem.
+on the native file system.
+.TP
+.BI list_quota " quota_type"
+Display quota information for given quota type (user, group, or project).
.TP
.BI ln " filespec dest_file"
Create a link named
.IR filespec .
Note this does not adjust the inode reference counts.
.TP
-.BI logdump " [-acs] [-b block] [-i filespec] [-f journal_file] [output_file]"
+.BI logdump " [-acsOS] [-b block] [-i filespec] [-f journal_file] [output_file]"
Dump the contents of the ext3 journal. By default, dump the journal inode as
specified in the superblock. However, this can be overridden with the
.I \-i
journal.
.IP
The
+.I \-S
+option causes
+.B logdump
+to print the contents of the journal superblock.
+.IP
+The
.I \-a
option causes the
.B logdump
.I \-b
option causes
.B logdump
-to print all journal records that are refer to the specified block.
+to print all journal records that refer to the specified block.
The
.I \-c
option will print out the contents of all of the data blocks selected by
and
.I \-b
options.
+.IP
+The
+.I \-O
+option causes logdump to display old (checkpointed) journal entries.
+This can be used to try to track down journal problems even after the
+journal has been replayed.
.TP
-.BI ls " [-d] [-l] [-p] filespec"
+.BI ls " [-l] [-c] [-d] [-p] [-r] filespec"
Print a listing of the files in the directory
.IR filespec .
The
+.I \-c
+flag causes directory block checksums (if present) to be displayed.
+The
.I \-d
flag will list deleted entries in the directory.
The
flag will list the files in a format which is more easily parsable by
scripts, as well as making it more clear when there are spaces or other
non-printing characters at the end of filenames.
+The
+.I \-r
+flag will force the printing of the filename, even if it is encrypted.
+.TP
+.BI list_deleted_inodes " [limit]"
+List deleted inodes, optionally limited to those deleted within
+.I limit
+seconds ago. Also available as
+.BR lsdel .
+.IP
+This command was useful for recovering from accidental file deletions
+for ext2 file systems. Unfortunately, it is not useful for this purpose
+if the files were deleted using ext3 or ext4, since the inode's
+data blocks are no longer available after the inode is released.
.TP
.BI modify_inode " filespec"
Modify the contents of the inode structure in the inode
flag will enable checking the file type information in the directory
entry to make sure it matches the inode's type.
.TP
-.BI open " [-weficD] [-b blocksize] [-s superblock] device"
-Open a filesystem for editing. The
+.BI open " [-weficD] [-b blocksize] [-d image_filename] [-s superblock] [-z undo_file] device"
+Open a file system for editing. 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
+flag forces the file system to be opened even if there are some unknown
+or incompatible file system features which would normally
+prevent the file system from being opened. The
.I -e
-flag causes the filesystem to be opened in exclusive mode. The
-.IR -b ", " -c ", " -i ", " -s ", " -w ", and " -D
+flag causes the file system to be opened in exclusive mode. The
+.IR -b ", " -c ", " -d ", " -i ", " -s ", " -w ", and " -D
options behave the same as the command-line options to
.BR debugfs .
.TP
.I start_blk
through to the end of the file will be deallocated.
.TP
-.I symlink filespec target
+.BI symlink " filespec target"
Make a symbolic link.
.TP
.B pwd
Quit
.B debugfs
.TP
-.BI rdump " directory destination"
+.BI rdump " directory[...] destination"
Recursively dump
-.I directory
+.IR directory ,
+or multiple
+.IR directories ,
and all its contents (including regular files, symbolic links, and other
directories) into the named
-.I destination
-which should be an existing directory on the native filesystem.
+.IR destination ,
+which should be an existing directory on the native file system.
.TP
.BI rm " pathname"
Unlink
Also available as
.BR set_bg .
.TP
+.BI set_current_time " time"
+Set current time in seconds since Unix epoch to use when setting file system
+fields.
+.TP
.BI seti " filespec [num]"
Mark inode
.I filespec
Also available as
.BR ssv .
.TP
+.B show_debugfs_params
+Display
+.B debugfs
+parameters such as information about currently opened file system.
+.TP
.BI show_super_stats " [-h]"
List the contents of the super block and the block group descriptors. If the
.I -h
Display the contents of the inode structure of the inode
.IR filespec .
.TP
+.B supported_features
+Display file system features supported by this version of
+.BR debugfs .
+.TP
.BI testb " block [count]"
Test if the block number
.I block
.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
+to check the file system and link all of the recovered inodes to the
lost+found directory.
.TP
.BI unlink " pathname"
.BI write " source_file out_file"
Copy the contents of
.I source_file
-into a newly-created file in the filesystem named
+into a newly-created file in the file system named
.IR out_file .
.TP
.BI zap_block " [-f filespec] [-o offset] [-l length] [-p pattern] block_num"
-.TP
Overwrite the block specified by
.I block_num
with zero (NUL) bytes, or if
.BR dumpe2fs (8),
.BR tune2fs (8),
.BR e2fsck (8),
-.BR mke2fs (8)
+.BR mke2fs (8),
+.BR ext4 (5)
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff