From: Martin Wilck <mwi...@arcor.de> Update documentation for btrfs-debug-tree, and add pages for btrfs-search-metadata and btrfs-raw.
Signed-off-by: Martin Wilck <mwi...@arcor.de> --- Documentation/Makefile | 2 + Documentation/btrfs-debug-tree.txt | 10 +++++ Documentation/btrfs-raw.txt | 54 +++++++++++++++++++++++++++++ Documentation/btrfs-search-metadata.txt | 57 +++++++++++++++++++++++++++++++ 4 files changed, 123 insertions(+), 0 deletions(-) create mode 100644 Documentation/btrfs-raw.txt create mode 100644 Documentation/btrfs-search-metadata.txt diff --git a/Documentation/Makefile b/Documentation/Makefile index ef4f1bd..354c412 100644 --- a/Documentation/Makefile +++ b/Documentation/Makefile @@ -5,6 +5,8 @@ MAN8_TXT = MAN8_TXT += btrfs.txt MAN8_TXT += btrfs-convert.txt MAN8_TXT += btrfs-debug-tree.txt +MAN8_TXT += btrfs-raw.txt +MAN8_TXT += btrfs-search-metadata.txt MAN8_TXT += btrfs-find-root.txt MAN8_TXT += btrfs-image.txt MAN8_TXT += btrfs-map-logical.txt diff --git a/Documentation/btrfs-debug-tree.txt b/Documentation/btrfs-debug-tree.txt index 23fc115..69a547d 100644 --- a/Documentation/btrfs-debug-tree.txt +++ b/Documentation/btrfs-debug-tree.txt @@ -25,8 +25,18 @@ Print detailed extents info. Print info of btrfs device and root tree dirs only. -r:: Print info of roots only. +-u:: +Print info of UUID tree only. +-R:: +Print info of roots and root backups. +-t <object id>:: +Only print the subvolume tree with given object ID. +-B <backup_num>:: +Start at backup root from superblock rather than current root. -b <block_num>:: Print info of the specified block only. +-f:: +Follow (descend) the (sub)tree rooted at the block given with -b. EXIT STATUS ----------- diff --git a/Documentation/btrfs-raw.txt b/Documentation/btrfs-raw.txt new file mode 100644 index 0000000..ae7bd2d --- /dev/null +++ b/Documentation/btrfs-raw.txt @@ -0,0 +1,54 @@ +btrfs-raw(8) +============ + +NAME +---- +btrfs-raw - low-level manipulation of btrfs meta data blocks. + +SYNOPSIS +-------- +*btrfs-raw* [[-r|-w] <bytenr>] <device> + +DESCRIPTION +----------- +*btrfs-raw* is used to dump the raw contents of the given logical block +of a btrfs device to stdout, or write raw data read from stdin to the +given logical block. + +*THIS TOOL IS DANGEROUS; IT MAY CORRUPT YOUR FILESYSTEM BEYOND REPAIR!!* + +Please exert extreme caution when writing modified blocks to disk. You +should make a backup copy of the entire file system before doing so, even +if the file system is already corrupted. Make sure you have a thorough +understanding of the btrfs disk data structures before making any changes. + +*YOU USE THIS TOOL AT YOUR OWN RISK!* + +OPTIONS +------- +-r <bytenr>:: +Read the logical block starting at <bytenr> and write the raw contents +to stdout (caution, binary data). +-w <bytenr>:: +Write the logical block starting at <bytenr> to disk, reading data from +stdin. The tool will adjust the header checksum before writing to disk. + +EXIT STATUS +----------- +*btrfs-raw* will return 0 if no error happened. +If any problems happened, 1 will be returned. + +EXAMPLE +------- + +`btrfs-raw -r 874991616 /dev/sda >/tmp/blob` + +`btrfs-raw -w 874991616 /dev/sda </tmp/blob` + +Dump the data of the given block to a file and write it back. +Between these operations, a hex editor could be used to manually fix +inconsistencies in the meta data. + +SEE ALSO +-------- +`mkfs.btrfs`(8), `btrfs-debug-tree`(8) diff --git a/Documentation/btrfs-search-metadata.txt b/Documentation/btrfs-search-metadata.txt new file mode 100644 index 0000000..d97295b --- /dev/null +++ b/Documentation/btrfs-search-metadata.txt @@ -0,0 +1,57 @@ +btrfs-search-metadata(8) +======================== + +NAME +---- +btrfs-search-metadata - search for certain nodes or leaves in btrfs metadata + +SYNOPSIS +-------- +*btrfs-search-metadata* [options] <device> + +DESCRIPTION +----------- +*btrfs-search-metadata* is used to dump the meta data of a device, or to +selectively dump nodes or leaves matching certain conditions. + +Unlike `btrfs-dump-tree`, this tool will also find tree "branches" that +are disconnected from the root tree, and previous meta data copies. If a +corruption occurs, this may be useful for finding old, still healthy copies. + +This is maybe useful for analyzing filesystem state or inconsistence and has +a positive educational effect on understanding the internal structure. +<device> is the device file where the filesystem is stored. + +OPTIONS +------- +-k <object id>/<key type>/<offset>:: +Search for leaves and nodes containing the given key. +-g <generation>:: +Search for leaves and nodes with the given generation (transid). +-l <level>:: +Search for nodes with the given level, or leaves (level 0). +-t <object id>:: +Search for leaves and nodes with the given owner object ID. +-L:: +dump full content of found nodes or leaves, like btrfs-debug-tree. + +EXIT STATUS +----------- +*btrfs-search-metadata* will return 0 if no error happened. +If any problems happened, 1 will be returned. + +EXAMPLE +------- + +`btrfs-search-metadata -t 260 -l 0 -k 256/1/0 /dev/sda` + +Search the btrfs file system on `/dev/sda` for leaves belonging to +subvolume 260 and containing the first inode item (type 1: inode item, +object ID 256: first available object ID). + +See `ctree.h` in the btrfs source code and the btrfs Wiki for +assigned object IDs and key types. + +SEE ALSO +-------- +`mkfs.btrfs`(8), `btrfs-debug-tree`(8) -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
