[PATCH v4 2/2] btrfs-progs: cmds: Add subcommand that dumps file extents
From: Sidong Yang <hidden>
Date: 2021-07-18 06:46:28
Subsystem:
kernel build + files below scripts/ (unless maintained elsewhere), the rest · Maintainers:
Nathan Chancellor, Nicolas Schier, Linus Torvalds
This patch adds an subcommand in inspect-internal. It dumps file extents of the file that user provided. It helps to show the internal information about file extents comprise the file. Signed-off-by: Sidong Yang <redacted> --- Makefile | 2 +- cmds/commands.h | 2 +- cmds/inspect-dump-file-extents.c | 134 +++++++++++++++++++++++++++++++ cmds/inspect.c | 1 + 4 files changed, 137 insertions(+), 2 deletions(-) create mode 100644 cmds/inspect-dump-file-extents.c
diff --git a/Makefile b/Makefile
index a1cc457b..911e16de 100644
--- a/Makefile
+++ b/Makefile@@ -156,7 +156,7 @@ cmds_objects = cmds/subvolume.o cmds/filesystem.o cmds/device.o cmds/scrub.o \ cmds/restore.o cmds/rescue.o cmds/rescue-chunk-recover.o \ cmds/rescue-super-recover.o \ cmds/property.o cmds/filesystem-usage.o cmds/inspect-dump-tree.o \ - cmds/inspect-dump-super.o cmds/inspect-tree-stats.o cmds/filesystem-du.o \ + cmds/inspect-dump-super.o cmds/inspect-tree-stats.o cmds/inspect-dump-file-extents.o cmds/filesystem-du.o \ mkfs/common.o check/mode-common.o check/mode-lowmem.o libbtrfs_objects = common/send-stream.o common/send-utils.o kernel-lib/rbtree.o btrfs-list.o \ kernel-lib/radix-tree.o common/extent-cache.o kernel-shared/extent_io.o \
diff --git a/cmds/commands.h b/cmds/commands.h
index 8fa85d6c..55de248e 100644
--- a/cmds/commands.h
+++ b/cmds/commands.h@@ -154,5 +154,5 @@ DECLARE_COMMAND(select_super); DECLARE_COMMAND(dump_super); DECLARE_COMMAND(debug_tree); DECLARE_COMMAND(rescue); - +DECLARE_COMMAND(inspect_dump_file_extents); #endif
diff --git a/cmds/inspect-dump-file-extents.c b/cmds/inspect-dump-file-extents.c
new file mode 100644
index 00000000..5e5bc6f7
--- /dev/null
+++ b/cmds/inspect-dump-file-extents.c@@ -0,0 +1,134 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include <unistd.h> +#include <stdio.h> +#include <fcntl.h> + +#include <sys/ioctl.h> + +#include "common/utils.h" +#include "cmds/commands.h" +#include "kernel-shared/print-tree.h" + +static const char * const cmd_inspect_dump_file_extents_usage[] = { + "btrfs inspect-internal dump-extent path", + "Dump file extent in a textual form", + NULL +}; + +static int cmd_inspect_dump_file_extents(const struct cmd_struct *cmd, + int argc, char **argv) +{ + int fd; + struct stat statbuf; + struct btrfs_ioctl_ino_lookup_args lookup; + struct btrfs_ioctl_search_args args; + struct btrfs_ioctl_search_key *sk = &args.key; + struct btrfs_file_extent_item *extent_item; + struct btrfs_ioctl_search_header *header; + u64 buf_off; + u64 len; + u64 start; + u64 disk_bytenr; + u64 disk_num_bytes; + u64 offset; + int ret; + int i; + char compress_str[BTRFS_COMPRESS_STR_LEN]; + + fd = open(argv[optind], O_RDONLY); + if (fd < 0) { + error("cannot open %s: %m", argv[optind]); + ret = 1; + goto out; + } + + if (fstat(fd, &statbuf) < 0) { + error("failed to fstat %s: %m", argv[optind]); + ret = 1; + goto out; + } + + lookup.treeid = 0; + lookup.objectid = BTRFS_FIRST_FREE_OBJECTID; + + if (ioctl(fd, BTRFS_IOC_INO_LOOKUP, &lookup) < 0) { + error("failed to lookup inode %s: %m", argv[optind]); + ret = 1; + goto out; + } + + sk->tree_id = lookup.treeid; + sk->min_objectid = statbuf.st_ino; + sk->max_objectid = statbuf.st_ino; + sk->min_offset = 0; + sk->max_offset = UINT64_MAX; + sk->min_transid = 0; + sk->max_transid = UINT64_MAX; + sk->min_type = sk->max_type = BTRFS_EXTENT_DATA_KEY; + sk->nr_items = UINT32_MAX; + +again: + if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args)) { + error("failed to search tree ioctl %s: %m", argv[optind]); + ret = 1; + goto out; + } + + buf_off = 0; + for(i=0; i<sk->nr_items; ++i) { + header = (struct btrfs_ioctl_search_header *)(args.buf + buf_off); + + if (btrfs_search_header_type(header) == BTRFS_EXTENT_DATA_KEY) { + extent_item = (struct btrfs_file_extent_item *)(header + 1); + start = btrfs_search_header_offset(header); + + printf("type = %s, start = %llu, ", + btrfs_file_extent_type_to_str(extent_item->type), start); + switch (extent_item->type) { + case BTRFS_FILE_EXTENT_INLINE: + len = le64_to_cpu(extent_item->ram_bytes); + printf("len = %llu\n", len); + break; + case BTRFS_FILE_EXTENT_REG: + case BTRFS_FILE_EXTENT_PREALLOC: + len = le64_to_cpu(extent_item->num_bytes); + disk_bytenr = le64_to_cpu(extent_item->disk_bytenr); + disk_num_bytes = le64_to_cpu(extent_item->disk_num_bytes); + offset = le64_to_cpu(extent_item->offset); + btrfs_compress_type_to_str(extent_item->compression, compress_str); + printf("len = %llu, disk_bytenr = %llu, disk_num_bytes = %llu," + " offset = %llu, compression = %s\n", + len, disk_bytenr, disk_num_bytes, offset, compress_str); + + break; + } + + } + buf_off += sizeof(*header) + btrfs_search_header_len(header); + } + if (sk->nr_items > 512) { + sk->nr_items = UINT32_MAX; + sk->min_offset = start + 1; + goto again; + } + ret = 0; +out: + close(fd); + return ret; +} +DEFINE_SIMPLE_COMMAND(inspect_dump_file_extents, "dump-file-extents");
diff --git a/cmds/inspect.c b/cmds/inspect.c
index 2ef5f4b6..dfb0e27b 100644
--- a/cmds/inspect.c
+++ b/cmds/inspect.c@@ -696,6 +696,7 @@ static const struct cmd_group inspect_cmd_group = { &cmd_struct_inspect_dump_tree, &cmd_struct_inspect_dump_super, &cmd_struct_inspect_tree_stats, + &cmd_struct_inspect_dump_file_extents, NULL } };
--
2.25.1