.\"
.TH DEBUGFS 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
.SH NAME
-debugfs \- ext2/ext3 file system debugger
+debugfs \- ext2/ext3/ext4 file system debugger
.SH SYNOPSIS
.B debugfs
[
-.B \-Vwci
+.B \-DVwcin
]
[
.B \-b
The
.B debugfs
program is an interactive file system debugger. It can be used to
-examine and change the state of an ext2 file system.
+examine and change the state of an ext2, ext3, or ext4 file system.
.br
.I device
-is the special file corresponding to the device containing the ext2
+is the special file corresponding to the device containing the
file system (e.g /dev/hdXX).
.SH OPTIONS
.TP
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
and execute them. When
.B debugfs
is finished executing those commands, it will exit.
-.TP
+.TP
+.I -D
+Causes
+.B debugfs
+to open the device using Direct I/O, bypassing the buffer cache. Note
+that some Linux devices, notably device mapper as of this writing, do
+not support Direct I/O.
+.TP
.I -R request
Causes
.B debugfs
.B debugfs
supports.
.TP
+.I blocks filespace
+Print the blocks used by the inode
+.I filespec
+to stdout.
+.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 block_dump [-f out_file] block_num
+Dump the contents of a block, optionally to
+.IR out_file .
+.TP
.I cat filespec
Dump the contents of the inode
.I filespec
Change the root directory to be the directory
.IR filespec .
.TP
-.I close
-Close the currently open file system.
+.I close [-a]
+Close the currently open file system. If the
+.I -a
+option is specified, write out any changes to the superblock and block
+group descriptors to all of the backup superblocks, not just to the
+master superblock.
.TP
.I clri file
Clear the contents of the inode
.IR file .
.TP
-.I dump [-p] filspec out_file
+.I dirsearch filespec filename
+Search the directory
+.I filespec
+for
+.IR filename .
+.TP
+.I dump [-p] filespec out_file
Dump the contents of the inode
.I filespec
to the output file
to match
.IR filespec .
.TP
+.I dump_mmp
+Display the multiple-mount protection (mmp) field values.
+.TP
+.I dx_hash [-h hash_alg] [-s hash_seed] filename
+Calculate the directory hash of
+.IR filename .
+The hash algorithm specified with
+.I -h
+may be "legacy" "half_md4" or "tea".
+The hash seed specified with
+.I -s
+must be in UUID format.
+.TP
+.I dump_extents [-n] [-l] filespec
+Dump the the extent tree of the inode
+.IR filespec .
+The
+.I -n
+flag will cause
+.I dump_extents
+to only display the interior nodes in the extent tree. The
+.I -l
+flag cause
+.I dump_extents
+to only display the leaf nodes in the extent tree.
+.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
+may not necessarily by accurate and does not indicate a problem or
+corruption in the file system.)
+.TP
.I expand_dir filespec
Expand the directory
.IR filespec .
or clearing any filesystem features that were requested, print the current
state of the filesystem feature set.
.TP
+.I filefrag [-dvr] filespec
+Print the number of contiguous extents in
+.IR filespec .
+If
+.I filespec
+is a directory and the
+.I -d
+option is not specified,
+.I filefrag
+will print the number of contiguous extents for each file in
+the directory. The
+.I -v
+option will cause
+.I filefrag
+print a tabular listing of the contiguous extents in the
+file. The
+.I -r
+option will cause
+.I filefrag
+to do a recursive listing of the directory.
+.TP
.I find_free_block [count [goal]]
Find the first
.I count
.I block
will be marked as not allocated.
.TP
-.I freei filespec
+.I freefrag [-c chunk_kb ]
+Report free space fragmentation on the currently open file system.
+If the
+.I \-c
+option is specified then the filefrag command will print how many free
+chunks of size
+.I chunk_kb
+can be found in the file system. The chunk size must be a power of two
+and be larger than the file system block size.
+.TP
+.I freei filespec [num]
Free the inode specified by
.IR filespec .
+If
+.I num
+is specified, also clear num-1 inodes after the specified inode.
.TP
.I help
Print a list of commands understood by
-.BR debugfs (8).
+.BR debugfs .
+.TP
+.I htree_dump filespec
+Dump the hash-indexed directory
+.IR filespec ,
+showing its tree structure.
.TP
.I icheck block ...
Print a listing of the inodes which use the one or more blocks specified
.I \-b
options.
.TP
-.I ls [-l] [-d] [-p] filespec
+.I ls [-l] [-c] [-d] [-p] 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 \-c
+flag causes directory block checksums (if present) to be displayed.
+The
.I \-d
flag will list deleted entries in the directory.
The
.I \-p
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-prinitng characters at the end of filenames.
+non-printing characters at the end of filenames.
.TP
.I modify_inode filespec
Modify the contents of the inode structure in the inode
.I minor
device numbers must be specified.
.TP
-.I ncheck inode_num ...
+.I ncheck [-c] inode_num ...
Take the requested list of inode numbers, and print a listing of pathnames
-to those inodes.
+to those inodes. The
+.I -c
+flag will enable checking the file type information in the directory
+entry to make sure it matches the inode's type.
.TP
-.I open [-w] [-e] [-f] [-i] [-c] [-b blocksize] [-s superblock] device
+.I open [-w] [-e] [-f] [-i] [-c] [-D] [-b blocksize] [-s superblock] device
Open a filesystem for editing. The
.I -f
flag forces the filesystem to be opened even if there are some unknown
prevent the filesystem from being opened. The
.I -e
flag causes the filesystem to be opened in exclusive mode. The
-.IR -b ", " -c ", " -i ", " -s ", and " -w
+.IR -b ", " -c ", " -i ", " -s ", " -w ", and " -D
options behave the same as the command-line options to
.BR debugfs .
.TP
+.I punch filespec start_blk [end_blk]
+Delete the blocks in the inode ranging from
+.I start_blk
+to
+.IR end_blk .
+If
+.I end_blk
+is omitted then this command will function as a truncate command; that
+is, all of the blocks starting at
+.I start_blk
+through to the end of the file will be deallocated.
+.TP
+.I symlink filespec target
+Make a symbolic link.
+.TP
.I pwd
Print the current working directory.
.TP
has value
.I value.
.TP
-.I seti filespec
+.I seti filespec [num]
Mark inode
.I filespec
-as in use in the inode bitmap.
+as in use in the inode bitmap. If
+.I num
+is specified, also set num-1 inodes after the specified inode.
.TP
.I set_inode_field filespec field value
Modify the inode specified by
can be displayed by using the command:
.B set_inode_field -l
.TP
+.I set_mmp_value field value
+Modify the multiple-mount protection (mmp) data so that the
+mmp field
+.I field
+has value
+.I value.
+The list of valid mmp fields which can be set via this command
+can be displayed by using the command:
+.B set_mmp_value -l
+.TP
.I set_super_value field value
Set the superblock field
.I field
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.
+lost+found directory.
.TP
.I unlink pathname
Remove the link specified by
and copy the contents of
.I source_file
into the destination file.
+.TP
+.I zap_block [-f file] [-o offset] [-l length] [-p pattern] block_num
+Zero, or pattern-fill, portions of a block within a file or
+within the filesystem.
+.TP
+.I zap_block [-f file] [-b bit] block_num
+Bit-flip portions of a block within a file or
+within the filesystem.
.SH ENVIRONMENT VARIABLES
.TP
.B DEBUGFS_PAGER, PAGER
The
-.BR debugfs (8)
+.B debugfs
program always pipes the output of the some commands through a
pager program. These commands include:
.IR show_super_stats ,
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff