Later we'll need to know which compression method to use for the metadata file in order to initialise a valid metadata file descriptor, and that requires reading an initial chunk. So it makes sense to combine the open_metadata() function with restore_init() which reads the preamble from the metadata file.
Signed-off-by: Andrew Price <[email protected]> --- gfs2/edit/savemeta.c | 77 ++++++++++++++++++++------------------------ 1 file changed, 35 insertions(+), 42 deletions(-) diff --git a/gfs2/edit/savemeta.c b/gfs2/edit/savemeta.c index ad565c1f..f77c6bf7 100644 --- a/gfs2/edit/savemeta.c +++ b/gfs2/edit/savemeta.c @@ -999,45 +999,6 @@ void savemeta(char *out_fn, int saveoption, int gziplevel) exit(0); } -static off_t restore_init(struct metafd *mfd, struct savemeta_header *smh) -{ - int err; - unsigned i; - size_t rs; - char buf[256]; - off_t startpos = 0; - struct gfs2_meta_header sbmh; - - err = read_header(mfd, smh); - if (err < 0) { - exit(1); - } else if (check_header(smh) != 0) { - printf("No valid file header found. Falling back to old format...\n"); - } else if (err == 0) { - startpos = sizeof(*smh); - } - - mfd->seek(mfd, startpos, SEEK_SET); - rs = mfd->read(mfd, buf, sizeof(buf)); - if (rs != sizeof(buf)) { - fprintf(stderr, "Error: File is too small.\n"); - exit(1); - } - /* Scan for the beginning of the file body. Required to support old formats(?). */ - for (i = 0; i < (256 - sizeof(struct saved_metablock) - sizeof(sbmh)); i++) { - off_t off = i + sizeof(struct saved_metablock); - - memcpy(&sbmh, &buf[off], sizeof(sbmh)); - if (sbmh.mh_magic == cpu_to_be32(GFS2_MAGIC) && - sbmh.mh_type == cpu_to_be32(GFS2_METATYPE_SB)) - break; - } - if (i == (sizeof(buf) - sizeof(struct saved_metablock) - sizeof(sbmh))) - i = 0; - return startpos + i; /* File offset of saved sb */ -} - - static int restore_block(struct metafd *mfd, struct saved_metablock *svb, char *buf, uint16_t maxlen) { int ret; @@ -1223,8 +1184,15 @@ static void complain(const char *complaint) "<dest file system>\n"); } -static int open_metadata(const char *path, struct metafd *mfd) +static int restore_init(const char *path, struct metafd *mfd, struct savemeta_header *smh, off_t *pos) { + struct gfs2_meta_header sbmh; + off_t startpos = 0; + char buf[256]; + unsigned i; + size_t rs; + int err; + mfd->filename = path; mfd->fd = open(path, O_RDONLY|O_CLOEXEC); if (mfd->fd < 0) { @@ -1241,6 +1209,32 @@ static int open_metadata(const char *path, struct metafd *mfd) perror("gzdopen"); return 1; } + err = read_header(mfd, smh); + if (err < 0) { + return 1; + } else if (check_header(smh) != 0) { + printf("No valid file header found. Falling back to old format...\n"); + } else if (err == 0) { + startpos = sizeof(*smh); + } + mfd->seek(mfd, startpos, SEEK_SET); + rs = mfd->read(mfd, buf, sizeof(buf)); + if (rs != sizeof(buf)) { + fprintf(stderr, "Error: File is too small.\n"); + return 1; + } + /* Scan for the beginning of the file body. Required to support old formats(?). */ + for (i = 0; i < (256 - sizeof(struct saved_metablock) - sizeof(sbmh)); i++) { + off_t off = i + sizeof(struct saved_metablock); + + memcpy(&sbmh, &buf[off], sizeof(sbmh)); + if (sbmh.mh_magic == cpu_to_be32(GFS2_MAGIC) && + sbmh.mh_type == cpu_to_be32(GFS2_METATYPE_SB)) + break; + } + if (i == (sizeof(buf) - sizeof(struct saved_metablock) - sizeof(sbmh))) + i = 0; + *pos = startpos + i; /* File offset of saved sb */ return 0; } @@ -1257,7 +1251,7 @@ void restoremeta(const char *in_fn, const char *out_device, uint64_t printonly) if (!printonly && !out_device) complain("No destination file system specified."); - error = open_metadata(in_fn, &mfd); + error = restore_init(in_fn, &mfd, &smh, &pos); if (error != 0) exit(error); @@ -1270,7 +1264,6 @@ void restoremeta(const char *in_fn, const char *out_device, uint64_t printonly) optional block no */ printonly = check_keywords(out_device); - pos = restore_init(&mfd, &smh); error = restore_super(&mfd, pos); if (error) exit(1); -- 2.24.1
