| Message ID | 1517831434-125895-1-git-send-email-marco.antonio.780@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Mon, Feb 05, 2018 at 09:50:34AM -0200, Marco A Benatto wrote: > Today, xfs_mdrestore from stdin will fail if the -i flag is > specified, because it attempts to rewind the stream after > the initial read of the metablock. This fails, and > results in an abort with "specified file is not a metadata > dump." > > Read the metablock exactly once in main(), validate the magic, > print informational flags if requested, and then pass it to > perform_restore() which will then continue the restore process. > > Reported-by: Darrick J. Wong <darrick.wong@oracle.com> > Signed-off-by: Marco A Benatto <marco.antonio.780@gmail.com> Looks ok, Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> > --- > mdrestore/xfs_mdrestore.c | 68 +++++++++++++++++++++++------------------------ > 1 file changed, 33 insertions(+), 35 deletions(-) > > diff --git a/mdrestore/xfs_mdrestore.c b/mdrestore/xfs_mdrestore.c > index 0bb4ac8..cbabd56 100644 > --- a/mdrestore/xfs_mdrestore.c > +++ b/mdrestore/xfs_mdrestore.c > @@ -51,57 +51,55 @@ print_progress(const char *fmt, ...) > progress_since_warning = 1; > } > > +/* > + * perform_restore() -- do the actual work to restore the metadump > + * > + * @src_f: A FILE pointer to the source metadump > + * @dst_fd: the file descriptor for the target file > + * @is_target_file: designates whether the target is a regular file > + * @mbp: pointer to metadump's first xfs_metablock, read and verified by the caller > + * > + * src_f should be positioned just past a read the previously validated metablock > + */ > static void > perform_restore( > FILE *src_f, > int dst_fd, > - int is_target_file) > + int is_target_file, > + const struct xfs_metablock *mbp) > { > - xfs_metablock_t *metablock; /* header + index + blocks */ > + struct xfs_metablock *metablock; /* header + index + blocks */ > __be64 *block_index; > char *block_buffer; > int block_size; > int max_indices; > int cur_index; > int mb_count; > - xfs_metablock_t tmb; > xfs_sb_t sb; > int64_t bytes_read; > > - /* > - * read in first blocks (superblock 0), set "inprogress" flag for it, > - * read in the rest of the file, and if complete, clear SB 0's > - * "inprogress flag" > - */ > - > - if (fread(&tmb, sizeof(tmb), 1, src_f) != 1) > - fatal("error reading from file: %s\n", strerror(errno)); > - > - if (be32_to_cpu(tmb.mb_magic) != XFS_MD_MAGIC) > - fatal("specified file is not a metadata dump\n"); > - > - block_size = 1 << tmb.mb_blocklog; > + block_size = 1 << mbp->mb_blocklog; > max_indices = (block_size - sizeof(xfs_metablock_t)) / sizeof(__be64); > > metablock = (xfs_metablock_t *)calloc(max_indices + 1, block_size); > if (metablock == NULL) > fatal("memory allocation failure\n"); > > - mb_count = be16_to_cpu(tmb.mb_count); > + mb_count = be16_to_cpu(mbp->mb_count); > if (mb_count == 0 || mb_count > max_indices) > fatal("bad block count: %u\n", mb_count); > > block_index = (__be64 *)((char *)metablock + sizeof(xfs_metablock_t)); > block_buffer = (char *)metablock + block_size; > > - if (fread(block_index, block_size - sizeof(tmb), 1, src_f) != 1) > + if (fread(block_index, block_size - sizeof(struct xfs_metablock), 1, src_f) != 1) > fatal("error reading from file: %s\n", strerror(errno)); > > if (block_index[0] != 0) > fatal("first block is not the primary superblock\n"); > > > - if (fread(block_buffer, mb_count << tmb.mb_blocklog, > + if (fread(block_buffer, mb_count << mbp->mb_blocklog, > 1, src_f) != 1) > fatal("error reading from file: %s\n", strerror(errno)); > > @@ -148,7 +146,7 @@ perform_restore( > > for (cur_index = 0; cur_index < mb_count; cur_index++) { > if (pwrite(dst_fd, &block_buffer[cur_index << > - tmb.mb_blocklog], block_size, > + mbp->mb_blocklog], block_size, > be64_to_cpu(block_index[cur_index]) << > BBSHIFT) < 0) > fatal("error writing block %llu: %s\n", > @@ -167,11 +165,11 @@ perform_restore( > if (mb_count > max_indices) > fatal("bad block count: %u\n", mb_count); > > - if (fread(block_buffer, mb_count << tmb.mb_blocklog, > + if (fread(block_buffer, mb_count << mbp->mb_blocklog, > 1, src_f) != 1) > fatal("error reading from file: %s\n", strerror(errno)); > > - bytes_read += block_size + (mb_count << tmb.mb_blocklog); > + bytes_read += block_size + (mb_count << mbp->mb_blocklog); > } > > if (progress_since_warning) > @@ -211,6 +209,7 @@ main( > int open_flags; > struct stat statbuf; > int is_target_file; > + struct xfs_metablock mb; > > progname = basename(argv[0]); > > @@ -237,7 +236,12 @@ main( > if (!show_info && argc - optind != 2) > usage(); > > - /* open source */ > + /* > + * open source and test if this really is a dump. The first metadump block > + * will be passed to perform_restore() which will continue to read the > + * file from this point. This avoids rewind the stream, which causes > + * restore to fail when source was being read from stdin. > + */ > if (strcmp(argv[optind], "-") == 0) { > src_f = stdin; > if (isatty(fileno(stdin))) > @@ -248,15 +252,12 @@ main( > fatal("cannot open source dump file\n"); > } > > - if (show_info) { > - xfs_metablock_t mb; > - > - if (fread(&mb, sizeof(mb), 1, src_f) != 1) > - fatal("error reading from file: %s\n", strerror(errno)); > - > - if (be32_to_cpu(mb.mb_magic) != XFS_MD_MAGIC) > - fatal("specified file is not a metadata dump\n"); > + if (fread(&mb, sizeof(mb), 1, src_f) != 1) > + fatal("error reading from file: %s\n", strerror(errno)); > + if (mb.mb_magic != cpu_to_be32(XFS_MD_MAGIC)) > + fatal("specified file is not a metadata dump\n"); > > + if (show_info) { > if (mb.mb_info & XFS_METADUMP_INFO_FLAGS) { > printf("%s: %sobfuscated, %s log, %s metadata blocks\n", > argv[optind], > @@ -270,9 +271,6 @@ main( > > if (argc - optind == 1) > exit(0); > - > - /* Go back to the beginning for the restore function */ > - fseek(src_f, 0L, SEEK_SET); > } > > optind++; > @@ -301,7 +299,7 @@ main( > if (dst_fd < 0) > fatal("couldn't open target \"%s\"\n", argv[optind]); > > - perform_restore(src_f, dst_fd, is_target_file); > + perform_restore(src_f, dst_fd, is_target_file, &mb); > > close(dst_fd); > if (src_f != stdin) > -- > 1.8.3.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/mdrestore/xfs_mdrestore.c b/mdrestore/xfs_mdrestore.c index 0bb4ac8..cbabd56 100644 --- a/mdrestore/xfs_mdrestore.c +++ b/mdrestore/xfs_mdrestore.c @@ -51,57 +51,55 @@ print_progress(const char *fmt, ...) progress_since_warning = 1; } +/* + * perform_restore() -- do the actual work to restore the metadump + * + * @src_f: A FILE pointer to the source metadump + * @dst_fd: the file descriptor for the target file + * @is_target_file: designates whether the target is a regular file + * @mbp: pointer to metadump's first xfs_metablock, read and verified by the caller + * + * src_f should be positioned just past a read the previously validated metablock + */ static void perform_restore( FILE *src_f, int dst_fd, - int is_target_file) + int is_target_file, + const struct xfs_metablock *mbp) { - xfs_metablock_t *metablock; /* header + index + blocks */ + struct xfs_metablock *metablock; /* header + index + blocks */ __be64 *block_index; char *block_buffer; int block_size; int max_indices; int cur_index; int mb_count; - xfs_metablock_t tmb; xfs_sb_t sb; int64_t bytes_read; - /* - * read in first blocks (superblock 0), set "inprogress" flag for it, - * read in the rest of the file, and if complete, clear SB 0's - * "inprogress flag" - */ - - if (fread(&tmb, sizeof(tmb), 1, src_f) != 1) - fatal("error reading from file: %s\n", strerror(errno)); - - if (be32_to_cpu(tmb.mb_magic) != XFS_MD_MAGIC) - fatal("specified file is not a metadata dump\n"); - - block_size = 1 << tmb.mb_blocklog; + block_size = 1 << mbp->mb_blocklog; max_indices = (block_size - sizeof(xfs_metablock_t)) / sizeof(__be64); metablock = (xfs_metablock_t *)calloc(max_indices + 1, block_size); if (metablock == NULL) fatal("memory allocation failure\n"); - mb_count = be16_to_cpu(tmb.mb_count); + mb_count = be16_to_cpu(mbp->mb_count); if (mb_count == 0 || mb_count > max_indices) fatal("bad block count: %u\n", mb_count); block_index = (__be64 *)((char *)metablock + sizeof(xfs_metablock_t)); block_buffer = (char *)metablock + block_size; - if (fread(block_index, block_size - sizeof(tmb), 1, src_f) != 1) + if (fread(block_index, block_size - sizeof(struct xfs_metablock), 1, src_f) != 1) fatal("error reading from file: %s\n", strerror(errno)); if (block_index[0] != 0) fatal("first block is not the primary superblock\n"); - if (fread(block_buffer, mb_count << tmb.mb_blocklog, + if (fread(block_buffer, mb_count << mbp->mb_blocklog, 1, src_f) != 1) fatal("error reading from file: %s\n", strerror(errno)); @@ -148,7 +146,7 @@ perform_restore( for (cur_index = 0; cur_index < mb_count; cur_index++) { if (pwrite(dst_fd, &block_buffer[cur_index << - tmb.mb_blocklog], block_size, + mbp->mb_blocklog], block_size, be64_to_cpu(block_index[cur_index]) << BBSHIFT) < 0) fatal("error writing block %llu: %s\n", @@ -167,11 +165,11 @@ perform_restore( if (mb_count > max_indices) fatal("bad block count: %u\n", mb_count); - if (fread(block_buffer, mb_count << tmb.mb_blocklog, + if (fread(block_buffer, mb_count << mbp->mb_blocklog, 1, src_f) != 1) fatal("error reading from file: %s\n", strerror(errno)); - bytes_read += block_size + (mb_count << tmb.mb_blocklog); + bytes_read += block_size + (mb_count << mbp->mb_blocklog); } if (progress_since_warning) @@ -211,6 +209,7 @@ main( int open_flags; struct stat statbuf; int is_target_file; + struct xfs_metablock mb; progname = basename(argv[0]); @@ -237,7 +236,12 @@ main( if (!show_info && argc - optind != 2) usage(); - /* open source */ + /* + * open source and test if this really is a dump. The first metadump block + * will be passed to perform_restore() which will continue to read the + * file from this point. This avoids rewind the stream, which causes + * restore to fail when source was being read from stdin. + */ if (strcmp(argv[optind], "-") == 0) { src_f = stdin; if (isatty(fileno(stdin))) @@ -248,15 +252,12 @@ main( fatal("cannot open source dump file\n"); } - if (show_info) { - xfs_metablock_t mb; - - if (fread(&mb, sizeof(mb), 1, src_f) != 1) - fatal("error reading from file: %s\n", strerror(errno)); - - if (be32_to_cpu(mb.mb_magic) != XFS_MD_MAGIC) - fatal("specified file is not a metadata dump\n"); + if (fread(&mb, sizeof(mb), 1, src_f) != 1) + fatal("error reading from file: %s\n", strerror(errno)); + if (mb.mb_magic != cpu_to_be32(XFS_MD_MAGIC)) + fatal("specified file is not a metadata dump\n"); + if (show_info) { if (mb.mb_info & XFS_METADUMP_INFO_FLAGS) { printf("%s: %sobfuscated, %s log, %s metadata blocks\n", argv[optind], @@ -270,9 +271,6 @@ main( if (argc - optind == 1) exit(0); - - /* Go back to the beginning for the restore function */ - fseek(src_f, 0L, SEEK_SET); } optind++; @@ -301,7 +299,7 @@ main( if (dst_fd < 0) fatal("couldn't open target \"%s\"\n", argv[optind]); - perform_restore(src_f, dst_fd, is_target_file); + perform_restore(src_f, dst_fd, is_target_file, &mb); close(dst_fd); if (src_f != stdin)
Today, xfs_mdrestore from stdin will fail if the -i flag is specified, because it attempts to rewind the stream after the initial read of the metablock. This fails, and results in an abort with "specified file is not a metadata dump." Read the metablock exactly once in main(), validate the magic, print informational flags if requested, and then pass it to perform_restore() which will then continue the restore process. Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Marco A Benatto <marco.antonio.780@gmail.com> --- mdrestore/xfs_mdrestore.c | 68 +++++++++++++++++++++++------------------------ 1 file changed, 33 insertions(+), 35 deletions(-)