Return-Path: Received: from mail-io1-f65.google.com ([209.85.166.65]:44573 "EHLO mail-io1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725958AbfAAVIM (ORCPT ); Tue, 1 Jan 2019 16:08:12 -0500 Received: by mail-io1-f65.google.com with SMTP id r200so23239203iod.11 for ; Tue, 01 Jan 2019 13:08:11 -0800 (PST) From: Artem Blagodarenko To: linux-ext4@vger.kernel.org Cc: adilger.kernel@dilger.ca Subject: [PATCH v6 4/4] ext2fs: automaticlly open backup superblocks Date: Tue, 1 Jan 2019 22:07:37 +0100 Message-Id: <20190101210737.87248-5-c17828@cray.com> In-Reply-To: <20190101210737.87248-1-c17828@cray.com> References: <20190101210737.87248-1-c17828@cray.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: e2image and e2fsck automatically try to open some backup superblocks, if only blocksize is set or passed superblock can't be opened. Try few backup superblocks (e.g. {1, 3, 5, 7, 9} * blocksize * 8). This code is moved to lib/support/. Signed-off-by: Artem Blagodarenko --- e2fsck/e2fsck.h | 2 - e2fsck/message.c | 3 +- e2fsck/unix.c | 14 +++-- e2fsck/util.c | 73 ------------------------- lib/support/Makefile.in | 8 ++- lib/support/sb_backup.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++++ lib/support/sb_backup.h | 20 +++++++ misc/e2image.c | 7 +++ 8 files changed, 185 insertions(+), 82 deletions(-) diff --git a/e2fsck/e2fsck.h b/e2fsck/e2fsck.h index 1c7a67cb..8576ef24 100644 --- a/e2fsck/e2fsck.h +++ b/e2fsck/e2fsck.h @@ -633,8 +633,6 @@ extern void e2fsck_write_inode_full(e2fsck_t ctx, unsigned long ino, #ifdef MTRACE extern void mtrace_print(char *mesg); #endif -extern blk64_t get_backup_sb(e2fsck_t ctx, ext2_filsys fs, - const char *name, io_manager manager); extern int ext2_file_type(unsigned int mode); extern int write_all(int fd, char *buf, size_t count); void dump_mmp_msg(struct mmp_struct *mmp, const char *fmt, ...) diff --git a/e2fsck/message.c b/e2fsck/message.c index 727f71d5..ffb40730 100644 --- a/e2fsck/message.c +++ b/e2fsck/message.c @@ -465,7 +465,8 @@ static _INLINE_ void expand_percent_expression(FILE *f, ext2_filsys fs, fprintf(f, "%*lld", width, (long long) ctx->blkcount); break; case 'S': - fprintf(f, "%llu", get_backup_sb(NULL, fs, NULL, NULL)); + fprintf(f, "%llu", get_first_backup_sb(NULL, NULL, fs, + NULL, NULL)); break; case 's': fprintf(f, "%*s", width, ctx->str ? ctx->str : "NULL"); diff --git a/e2fsck/unix.c b/e2fsck/unix.c index ddcf52a4..4ffc039e 100644 --- a/e2fsck/unix.c +++ b/e2fsck/unix.c @@ -1489,11 +1489,17 @@ restart: retval ? _("Superblock invalid,") : _("Group descriptors look bad...")); orig_superblock = ctx->superblock; - get_backup_sb(ctx, fs, ctx->filesystem_name, io_ptr); - if (fs) - ext2fs_close_free(&fs); orig_retval = retval; - retval = try_open_fs(ctx, flags, io_ptr, &fs); + retval = try_backups(ctx->filesystem_name, + ctx->io_options, + flags, &ctx->superblock, + &ctx->blocksize, io_ptr, &fs); + if (retval == 0) { + fs->priv_data = ctx; + e2fsck_set_bitmap_type(fs, + EXT2FS_BMAP64_RBTREE, + "default", NULL); + } if ((orig_retval == 0) && retval != 0) { if (fs) ext2fs_close_free(&fs); diff --git a/e2fsck/util.c b/e2fsck/util.c index db6a1cc1..e2caf3a2 100644 --- a/e2fsck/util.c +++ b/e2fsck/util.c @@ -549,79 +549,6 @@ void mtrace_print(char *mesg) } #endif -blk64_t get_backup_sb(e2fsck_t ctx, ext2_filsys fs, const char *name, - io_manager manager) -{ - struct ext2_super_block *sb; - io_channel io = NULL; - void *buf = NULL; - int blocksize; - blk64_t superblock, ret_sb = 8193; - - if (fs && fs->super) { - ret_sb = (fs->super->s_blocks_per_group + - fs->super->s_first_data_block); - if (ctx) { - ctx->superblock = ret_sb; - ctx->blocksize = fs->blocksize; - } - return ret_sb; - } - - if (ctx) { - if (ctx->blocksize) { - ret_sb = ctx->blocksize * 8; - if (ctx->blocksize == 1024) - ret_sb++; - ctx->superblock = ret_sb; - return ret_sb; - } - ctx->superblock = ret_sb; - ctx->blocksize = 1024; - } - - if (!name || !manager) - goto cleanup; - - if (manager->open(name, 0, &io) != 0) - goto cleanup; - - if (ext2fs_get_mem(SUPERBLOCK_SIZE, &buf)) - goto cleanup; - sb = (struct ext2_super_block *) buf; - - for (blocksize = EXT2_MIN_BLOCK_SIZE; - blocksize <= EXT2_MAX_BLOCK_SIZE ; blocksize *= 2) { - superblock = blocksize*8; - if (blocksize == 1024) - superblock++; - io_channel_set_blksize(io, blocksize); - if (io_channel_read_blk64(io, superblock, - -SUPERBLOCK_SIZE, buf)) - continue; -#ifdef WORDS_BIGENDIAN - if (sb->s_magic == ext2fs_swab16(EXT2_SUPER_MAGIC)) - ext2fs_swap_super(sb); -#endif - if ((sb->s_magic == EXT2_SUPER_MAGIC) && - (EXT2_BLOCK_SIZE(sb) == blocksize)) { - ret_sb = superblock; - if (ctx) { - ctx->superblock = superblock; - ctx->blocksize = blocksize; - } - break; - } - } - -cleanup: - if (io) - io_channel_close(io); - if (buf) - ext2fs_free_mem(&buf); - return (ret_sb); -} - /* * Given a mode, return the ext2 file type */ diff --git a/lib/support/Makefile.in b/lib/support/Makefile.in index 1d278642..03fdf555 100644 --- a/lib/support/Makefile.in +++ b/lib/support/Makefile.in @@ -22,7 +22,8 @@ OBJS= cstring.o \ quotaio.o \ quotaio_v2.o \ quotaio_tree.o \ - dict.o + dict.o \ + sb_backup.o SRCS= $(srcdir)/argv_parse.c \ $(srcdir)/cstring.c \ @@ -35,7 +36,8 @@ SRCS= $(srcdir)/argv_parse.c \ $(srcdir)/quotaio.c \ $(srcdir)/quotaio_tree.c \ $(srcdir)/quotaio_v2.c \ - $(srcdir)/dict.c + $(srcdir)/dict.c \ + $(srcdir)/sb_backup.c LIBRARY= libsupport LIBDIR= support @@ -168,3 +170,5 @@ quotaio_v2.o: $(srcdir)/quotaio_v2.c $(top_builddir)/lib/config.h \ $(srcdir)/quotaio_tree.h dict.o: $(srcdir)/dict.c $(top_builddir)/lib/config.h \ $(top_builddir)/lib/dirpaths.h $(srcdir)/dict.h +sb_backup.o: $(srcdir)/sb_backup.c $(top_builddir)/lib/config.h \ + $(srcdir)/sb_backup.h diff --git a/lib/support/sb_backup.c b/lib/support/sb_backup.c new file mode 100644 index 00000000..cfa671e5 --- /dev/null +++ b/lib/support/sb_backup.c @@ -0,0 +1,140 @@ +/* + * sb_backup.c -- helper functions for getting backup superblocks + * + * %Begin-Header% + * This file may be redistributed under the terms of the GNU Library + * General Public License, version 2. + * %End-Header% + */ + + +#include "config.h" +#include +#include + +#include "ext2fs/ext2_fs.h" +#include "ext2fs/ext2fs.h" + +blk64_t get_first_backup_sb(blk64_t *superblock, unsigned int *block_size, + ext2_filsys fs, const char *name, + io_manager manager) +{ + struct ext2_super_block *sb; + io_channel io = NULL; + void *buf = NULL; + int try_blocksize; + blk64_t try_superblock, ret_sb = 8193; + + /* superblock and block_size can be NULL if fs->super is passed */ + if (fs && fs->super) { + ret_sb = fs->super->s_blocks_per_group + + fs->super->s_first_data_block; + if (superblock) + *superblock = ret_sb; + if (block_size) + *block_size = fs->blocksize; + return ret_sb; + } + + if (*block_size) { + ret_sb = *block_size * 8; + if (*block_size == 1024) + ret_sb++; + *superblock = ret_sb; + return ret_sb; + } + + *superblock = ret_sb; + *block_size = 1024; + + if (!name || !manager) + goto cleanup; + + if (manager->open(name, 0, &io) != 0) + goto cleanup; + + if (ext2fs_get_mem(SUPERBLOCK_SIZE, &buf)) + goto cleanup; + sb = (struct ext2_super_block *) buf; + + for (try_blocksize = EXT2_MIN_BLOCK_SIZE; + try_blocksize <= EXT2_MAX_BLOCK_SIZE ; try_blocksize *= 2) { + try_superblock = try_blocksize*8; + if (try_blocksize == 1024) + try_superblock++; + io_channel_set_blksize(io, try_blocksize); + if (io_channel_read_blk64(io, try_superblock, + -SUPERBLOCK_SIZE, buf)) + continue; +#ifdef WORDS_BIGENDIAN + if (sb->s_magic == ext2fs_swab16(EXT2_SUPER_MAGIC)) + ext2fs_swap_super(sb); +#endif + if ((sb->s_magic == EXT2_SUPER_MAGIC) && + (EXT2_BLOCK_SIZE(sb) == try_blocksize)) { + ret_sb = try_superblock; + *superblock = try_superblock; + *block_size = try_blocksize; + break; + } + } + +cleanup: + if (io) + io_channel_close(io); + if (buf) + ext2fs_free_mem(&buf); + return ret_sb; +} + +errcode_t try_backups(const char *name, const char *io_options, + int flags, blk64_t *superblock, + unsigned int *block_size, io_manager manager, + ext2_filsys *ret_fs) +{ + errcode_t retval, retval2; + blk64_t try_block_number; + unsigned int i; + + /* + * Get first superblock location based on heuristic. + * Blocksize is also returned and used to find next + * superblock copy location. + */ + try_block_number = get_first_backup_sb(superblock, block_size, + *ret_fs, name, manager); + retval = ext2fs_open2(name, io_options, flags, try_block_number, + *block_size, manager, ret_fs); + if (!retval) + return 0; + + /* + * Try 3d, 5th, 7th, 9th superblock copy + */ + for (i = 3; i <= 9; i += 2) { + try_block_number = (i * (*block_size) * 8); + if (*block_size == 1024) + try_block_number++; + if (*ret_fs) { + ext2fs_free(*ret_fs); + *ret_fs = NULL; + } + retval2 = ext2fs_open2(name, io_options, flags, + try_block_number, *block_size, manager, + ret_fs); + /* + * Partition is too small to have this superblock copy. + * Return previous reading return code + */ + if (retval2 == EXT2_ET_SHORT_READ) + break; + + retval = retval2; + if (!retval) { + *superblock = try_block_number; + break; + } + } + + return retval; +} diff --git a/lib/support/sb_backup.h b/lib/support/sb_backup.h new file mode 100644 index 00000000..1e18e37c --- /dev/null +++ b/lib/support/sb_backup.h @@ -0,0 +1,20 @@ +/* + * sb_backup.h -- helper functions for getting backup superblocks + * + * %Begin-Header% + * This file may be redistributed under the terms of the GNU Library + * General Public License, version 2. + * %End-Header% + */ + +#include "ext2fs/ext2_fs.h" +#include "ext2fs/ext2fs.h" + +blk64_t get_first_backup_sb(blk64_t *superblock, unsigned int *block_size, + ext2_filsys fs, const char *name, + io_manager manager); + +errcode_t try_backups(const char *name, const char *io_options, + int flags, blk64_t *superblock, + unsigned int *block_size, io_manager manager, + ext2_filsys *ret_fs); diff --git a/misc/e2image.c b/misc/e2image.c index 3c881fee..786282ec 100644 --- a/misc/e2image.c +++ b/misc/e2image.c @@ -1623,6 +1623,13 @@ int main (int argc, char ** argv) sprintf(offset_opt, "offset=%llu", source_offset); retval = ext2fs_open2(device_name, offset_opt, open_flag, superblock, blocksize, unix_io_manager, &fs); + if (retval & (superblock | blocksize)) { + printf(_("Try backups in other location.\n")); + retval = try_backups(device_name, offset_opt, open_flag, + &superblock, &blocksize, + unix_io_manager, &fs); + printf(_("Use superblock %i.\n"), superblock); + } if (retval) { com_err (program_name, retval, _("while trying to open %s"), device_name); -- 2.14.3