Wrap the gzip functions that restoremeta uses and call them via function pointers, to provide the framework for supporting other compression methods.
Signed-off-by: Andrew Price <[email protected]> --- gfs2/edit/savemeta.c | 76 +++++++++++++++++++++++++++++++------------- 1 file changed, 54 insertions(+), 22 deletions(-) diff --git a/gfs2/edit/savemeta.c b/gfs2/edit/savemeta.c index 82d43d8f..ad565c1f 100644 --- a/gfs2/edit/savemeta.c +++ b/gfs2/edit/savemeta.c @@ -54,8 +54,43 @@ struct metafd { gzFile gzfd; const char *filename; int gziplevel; + int (*seek)(struct metafd *mfd, off_t off, int whence); + int (*read)(struct metafd *mfd, void *buf, unsigned len); + int (*iseof)(struct metafd *mfd); + void (*close)(struct metafd *mfd); + const char* (*strerr)(struct metafd *mfd); }; +static const char *gz_strerr(struct metafd *mfd) +{ + int err; + const char *errstr = gzerror(mfd->gzfd, &err); + + if (err == Z_ERRNO) + return strerror(errno); + return errstr; +} + +static int gz_seek(struct metafd *mfd, off_t off, int whence) +{ + return gzseek(mfd->gzfd, off, whence); +} + +static int gz_read(struct metafd *mfd, void *buf, unsigned len) +{ + return gzread(mfd->gzfd, buf, len); +} + +static int gz_iseof(struct metafd *mfd) +{ + return gzeof(mfd->gzfd); +} + +static void gz_close(struct metafd *mfd) +{ + gzclose(mfd->gzfd); +} + static uint64_t blks_saved; static uint64_t journal_blocks[MAX_JOURNALS_SAVED]; static uint64_t gfs1_journal_size = 0; /* in blocks */ @@ -853,8 +888,8 @@ static int read_header(struct metafd *mfd, struct savemeta_header *smh) size_t rs; struct savemeta_header smh_be = {0}; - gzseek(mfd->gzfd, 0, SEEK_SET); - rs = gzread(mfd->gzfd, &smh_be, sizeof(smh_be)); + mfd->seek(mfd, 0, SEEK_SET); + rs = mfd->read(mfd, &smh_be, sizeof(smh_be)); if (rs == -1) { perror("Failed to read savemeta file header"); return -1; @@ -982,8 +1017,8 @@ static off_t restore_init(struct metafd *mfd, struct savemeta_header *smh) startpos = sizeof(*smh); } - gzseek(mfd->gzfd, startpos, SEEK_SET); - rs = gzread(mfd->gzfd, buf, sizeof(buf)); + 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); @@ -1005,14 +1040,13 @@ static off_t restore_init(struct metafd *mfd, struct savemeta_header *smh) static int restore_block(struct metafd *mfd, struct saved_metablock *svb, char *buf, uint16_t maxlen) { - int gzerr; int ret; uint16_t checklen; const char *errstr; - ret = gzread(mfd->gzfd, svb, sizeof(*svb)); + ret = mfd->read(mfd, svb, sizeof(*svb)); if (ret < sizeof(*svb)) { - goto gzread_err; + goto read_err; } svb->blk = be64_to_cpu(svb->blk); svb->siglen = be16_to_cpu(svb->siglen); @@ -1036,21 +1070,19 @@ static int restore_block(struct metafd *mfd, struct saved_metablock *svb, char * } if (buf != NULL && maxlen != 0) { - ret = gzread(mfd->gzfd, buf, svb->siglen); + ret = mfd->read(mfd, buf, svb->siglen); if (ret < svb->siglen) { - goto gzread_err; + goto read_err; } } return 0; -gzread_err: - if (gzeof(mfd->gzfd)) +read_err: + if (mfd->iseof(mfd)) return 1; - errstr = gzerror(mfd->gzfd, &gzerr); - if (gzerr == Z_ERRNO) - errstr = strerror(errno); + errstr = mfd->strerr(mfd); fprintf(stderr, "Failed to restore block: %s\n", errstr); return -1; } @@ -1066,7 +1098,7 @@ static int restore_super(struct metafd *mfd, off_t pos) perror("Failed to restore super block"); exit(1); } - gzseek(mfd->gzfd, pos, SEEK_SET); + mfd->seek(mfd, pos, SEEK_SET); ret = restore_block(mfd, &svb, buf, sizeof(struct gfs2_sb)); if (ret == 1) { fprintf(stderr, "Reached end of file while restoring superblock\n"); @@ -1100,7 +1132,7 @@ static int find_highest_block(struct metafd *mfd, off_t pos, uint64_t fssize) struct saved_metablock svb = {0}; while (1) { - gzseek(mfd->gzfd, pos, SEEK_SET); + mfd->seek(mfd, pos, SEEK_SET); err = restore_block(mfd, &svb, NULL, 0); if (err == 1) break; @@ -1199,6 +1231,11 @@ static int open_metadata(const char *path, struct metafd *mfd) perror("Could not open metadata file"); return 1; } + mfd->seek = gz_seek; + mfd->read = gz_read; + mfd->iseof = gz_iseof; + mfd->close = gz_close; + mfd->strerr = gz_strerr; mfd->gzfd = gzdopen(mfd->fd, "rb"); if (!mfd->gzfd) { perror("gzdopen"); @@ -1207,11 +1244,6 @@ static int open_metadata(const char *path, struct metafd *mfd) return 0; } -static void close_metadata(struct metafd *mfd) -{ - gzclose(mfd->gzfd); -} - void restoremeta(const char *in_fn, const char *out_device, uint64_t printonly) { int error; @@ -1259,7 +1291,7 @@ void restoremeta(const char *in_fn, const char *out_device, uint64_t printonly) (printonly ? "print" : "restore"), (error ? "error" : "successful")); - close_metadata(&mfd); + mfd.close(&mfd); if (!printonly) close(sbd.device_fd); free(indirect); -- 2.24.1
