Add `--offset` option to allows users to specify an offset in the file where the filesystem will begin.
Suggested-by: Pavel Otchertsov <[email protected]> Closes: https://lore.kernel.org/r/caaxntogtd2nkknbphz+ver7nvnwvt0u02e+c8pn8zvfcxp5...@mail.gmail.com Signed-off-by: Gao Xiang <[email protected]> --- I plan to apply this version. dump/main.c | 10 ++++++++++ fsck/main.c | 10 ++++++++++ fuse/main.c | 5 ++--- include/erofs/config.h | 3 --- include/erofs/internal.h | 2 ++ lib/blobchunk.c | 1 + lib/io.c | 12 +++++++----- mkfs/main.c | 9 +++++++++ 8 files changed, 41 insertions(+), 11 deletions(-) diff --git a/dump/main.c b/dump/main.c index 293093d..a89fc6b 100644 --- a/dump/main.c +++ b/dump/main.c @@ -80,6 +80,7 @@ static struct option long_options[] = { {"device", required_argument, NULL, 3}, {"path", required_argument, NULL, 4}, {"ls", no_argument, NULL, 5}, + {"offset", required_argument, NULL, 6}, {0, 0, 0, 0}, }; @@ -124,6 +125,7 @@ static void usage(int argc, char **argv) " --device=X specify an extra device to be used together\n" " --ls show directory contents (INODE required)\n" " --nid=# show the target inode info of nid #\n" + " --offset=# skip # bytes at the beginning of IMAGE\n" " --path=X show the target inode info of path X\n", argv[0]); } @@ -136,6 +138,7 @@ static void erofsdump_print_version(void) static int erofsdump_parse_options_cfg(int argc, char **argv) { int opt, err; + char *endptr; while ((opt = getopt_long(argc, argv, "SVesh", long_options, NULL)) != -1) { @@ -177,6 +180,13 @@ static int erofsdump_parse_options_cfg(int argc, char **argv) case 5: dumpcfg.show_subdirectories = true; break; + case 6: + sbi.diskoffset = strtoull(optarg, &endptr, 0); + if (*endptr != '\0') { + erofs_err("invalid disk offset %s", optarg); + return -EINVAL; + } + break; default: return -EINVAL; } diff --git a/fsck/main.c b/fsck/main.c index 26cd131..e5c37be 100644 --- a/fsck/main.c +++ b/fsck/main.c @@ -48,6 +48,7 @@ static struct option long_options[] = { {"no-preserve", no_argument, 0, 9}, {"no-preserve-owner", no_argument, 0, 10}, {"no-preserve-perms", no_argument, 0, 11}, + {"offset", required_argument, 0, 12}, {0, 0, 0, 0}, }; @@ -97,6 +98,7 @@ static void usage(int argc, char **argv) " --device=X specify an extra device to be used together\n" " --extract[=X] check if all files are well encoded, optionally\n" " extract to X\n" + " --offset=# skip # bytes at the beginning of IMAGE\n" "\n" " -a, -A, -y no-op, for compatibility with fsck of other filesystems\n" "\n" @@ -123,6 +125,7 @@ static void erofsfsck_print_version(void) static int erofsfsck_parse_options_cfg(int argc, char **argv) { + char *endptr; int opt, ret; bool has_opt_preserve = false; @@ -216,6 +219,13 @@ static int erofsfsck_parse_options_cfg(int argc, char **argv) fsckcfg.preserve_perms = false; has_opt_preserve = true; break; + case 12: + sbi.diskoffset = strtoull(optarg, &endptr, 0); + if (*endptr != '\0') { + erofs_err("invalid disk offset %s", optarg); + return -EINVAL; + } + break; default: return -EINVAL; } diff --git a/fuse/main.c b/fuse/main.c index 5b2c64d..f07165c 100644 --- a/fuse/main.c +++ b/fuse/main.c @@ -547,7 +547,7 @@ static void usage(void) #endif fputs("usage: [options] IMAGE MOUNTPOINT\n\n" "Options:\n" - " --offset=# skip # bytes when reading IMAGE\n" + " --offset=# skip # bytes at the beginning of IMAGE\n" " --dbglevel=# set output message level to # (maximum 9)\n" " --device=# specify an extra device to be used together\n" #if FUSE_MAJOR_VERSION < 3 @@ -676,8 +676,7 @@ int main(int argc, char *argv[]) if (fusecfg.odebug && cfg.c_dbg_lvl < EROFS_DBG) cfg.c_dbg_lvl = EROFS_DBG; - cfg.c_offset = fusecfg.offset; - + sbi.diskoffset = fusecfg.offset; ret = dev_open_ro(&sbi, fusecfg.disk); if (ret) { fprintf(stderr, "failed to open: %s\n", fusecfg.disk); diff --git a/include/erofs/config.h b/include/erofs/config.h index e342722..89fe522 100644 --- a/include/erofs/config.h +++ b/include/erofs/config.h @@ -83,9 +83,6 @@ struct erofs_configure { char *fs_config_file; char *block_list_file; #endif - - /* offset when reading multi partition images */ - u64 c_offset; }; extern struct erofs_configure cfg; diff --git a/include/erofs/internal.h b/include/erofs/internal.h index 4d794ae..78b9f32 100644 --- a/include/erofs/internal.h +++ b/include/erofs/internal.h @@ -110,6 +110,8 @@ struct erofs_sb_info { struct erofs_xattr_prefix_item *xattr_prefixes; int devfd, devblksz; + /* offset when reading multi-part images */ + u64 diskoffset; u64 devsz; dev_t dev; unsigned int nblobs; diff --git a/lib/blobchunk.c b/lib/blobchunk.c index e4d0bad..6d2501e 100644 --- a/lib/blobchunk.c +++ b/lib/blobchunk.c @@ -448,6 +448,7 @@ int erofs_mkfs_dump_blobs(struct erofs_sb_info *sbi) pos_out = erofs_btell(bh, false); remapped_base = erofs_blknr(sbi, pos_out); + pos_out += sbi->diskoffset; if (blobfile) { pos_in = 0; ret = erofs_copy_file_range(fileno(blobfile), &pos_in, diff --git a/lib/io.c b/lib/io.c index c92f16c..bfae73a 100644 --- a/lib/io.c +++ b/lib/io.c @@ -194,6 +194,7 @@ int dev_write(struct erofs_sb_info *sbi, const void *buf, u64 offset, size_t len return -EINVAL; } + offset += sbi->diskoffset; if (offset >= sbi->devsz || len > sbi->devsz || offset > sbi->devsz - len) { erofs_err("Write posion[%" PRIu64 ", %zd] is too large beyond the end of device(%" PRIu64 ").", @@ -230,7 +231,7 @@ int dev_fillzero(struct erofs_sb_info *sbi, u64 offset, size_t len, bool padding #if defined(HAVE_FALLOCATE) && defined(FALLOC_FL_PUNCH_HOLE) if (!padding && fallocate(sbi->devfd, FALLOC_FL_PUNCH_HOLE | - FALLOC_FL_KEEP_SIZE, offset, len) >= 0) + FALLOC_FL_KEEP_SIZE, offset + sbi->diskoffset, len) >= 0) return 0; #endif while (len > erofs_blksiz(sbi)) { @@ -255,7 +256,7 @@ int dev_fsync(struct erofs_sb_info *sbi) return 0; } -int dev_resize(struct erofs_sb_info *sbi, unsigned int blocks) +int dev_resize(struct erofs_sb_info *sbi, erofs_blk_t blocks) { int ret; struct stat st; @@ -271,6 +272,7 @@ int dev_resize(struct erofs_sb_info *sbi, unsigned int blocks) } length = (u64)blocks * erofs_blksiz(sbi); + length += sbi->diskoffset; if (st.st_size == length) return 0; if (st.st_size > length) @@ -281,7 +283,8 @@ int dev_resize(struct erofs_sb_info *sbi, unsigned int blocks) if (fallocate(sbi->devfd, 0, st.st_size, length) >= 0) return 0; #endif - return dev_fillzero(sbi, st.st_size, length, true); + return dev_fillzero(sbi, st.st_size - sbi->diskoffset, + length, true); } int dev_read(struct erofs_sb_info *sbi, int device_id, @@ -292,8 +295,6 @@ int dev_read(struct erofs_sb_info *sbi, int device_id, if (cfg.c_dry_run) return 0; - offset += cfg.c_offset; - if (!buf) { erofs_err("buf is NULL"); return -EINVAL; @@ -301,6 +302,7 @@ int dev_read(struct erofs_sb_info *sbi, int device_id, if (!device_id) { fd = sbi->devfd; + offset += sbi->diskoffset; } else { if (device_id > sbi->nblobs) { erofs_err("invalid device id %d", device_id); diff --git a/mkfs/main.c b/mkfs/main.c index f024026..0517849 100644 --- a/mkfs/main.c +++ b/mkfs/main.c @@ -71,6 +71,7 @@ static struct option long_options[] = { #ifdef HAVE_ZLIB {"gzip", no_argument, NULL, 517}, #endif + {"offset", required_argument, NULL, 518}, {0, 0, 0, 0}, }; @@ -151,6 +152,7 @@ static void usage(int argc, char **argv) " --ignore-mtime use build time instead of strict per-file modification time\n" " --max-extent-bytes=# set maximum decompressed extent size # in bytes\n" " --preserve-mtime keep per-file modification time strictly\n" + " --offset=# skip # bytes at the beginning of IMAGE.\n" " --aufs replace aufs special files with overlayfs metadata\n" " --tar=[fi] generate an image from tarball(s)\n" " --ovlfs-strip=<0,1> strip overlayfs metadata in the target image (e.g. whiteouts)\n" @@ -571,6 +573,13 @@ static int mkfs_parse_options_cfg(int argc, char *argv[]) case 517: gzip_supported = true; break; + case 518: + sbi.diskoffset = strtoull(optarg, &endptr, 0); + if (*endptr != '\0') { + erofs_err("invalid disk offset %s", optarg); + return -EINVAL; + } + break; case 'V': version(); exit(0); -- 2.39.3
