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-rw-r--r--lib/ext2fs/closefs.c521
1 files changed, 521 insertions, 0 deletions
diff --git a/lib/ext2fs/closefs.c b/lib/ext2fs/closefs.c
new file mode 100644
index 0000000..69cbdd8
--- /dev/null
+++ b/lib/ext2fs/closefs.c
@@ -0,0 +1,521 @@
+/*
+ * closefs.c --- close an ext2 filesystem
+ *
+ * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
+ *
+ * %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 <stdio.h>
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <time.h>
+#include <string.h>
+
+#include "ext2_fs.h"
+#include "ext2fsP.h"
+
+static int test_root(unsigned int a, unsigned int b)
+{
+ while (1) {
+ if (a < b)
+ return 0;
+ if (a == b)
+ return 1;
+ if (a % b)
+ return 0;
+ a = a / b;
+ }
+}
+
+int ext2fs_bg_has_super(ext2_filsys fs, dgrp_t group)
+{
+ if (group == 0)
+ return 1;
+ if (ext2fs_has_feature_sparse_super2(fs->super)) {
+ if (group == fs->super->s_backup_bgs[0] ||
+ group == fs->super->s_backup_bgs[1])
+ return 1;
+ return 0;
+ }
+ if ((group <= 1) || !ext2fs_has_feature_sparse_super(fs->super))
+ return 1;
+ if (!(group & 1))
+ return 0;
+ if (test_root(group, 3) || (test_root(group, 5)) ||
+ test_root(group, 7))
+ return 1;
+
+ return 0;
+}
+
+/*
+ * ext2fs_super_and_bgd_loc2()
+ * @fs: ext2 fs pointer
+ * @group given block group
+ * @ret_super_blk: if !NULL, returns super block location
+ * @ret_old_desc_blk: if !NULL, returns location of the old block
+ * group descriptor
+ * @ret_new_desc_blk: if !NULL, returns location of meta_bg block
+ * group descriptor
+ * @ret_used_blks: if !NULL, returns number of blocks used by
+ * super block and group_descriptors.
+ *
+ * Returns errcode_t of 0
+ */
+errcode_t ext2fs_super_and_bgd_loc2(ext2_filsys fs,
+ dgrp_t group,
+ blk64_t *ret_super_blk,
+ blk64_t *ret_old_desc_blk,
+ blk64_t *ret_new_desc_blk,
+ blk_t *ret_used_blks)
+{
+ blk64_t group_block, super_blk = 0, old_desc_blk = 0, new_desc_blk = 0;
+ unsigned int meta_bg, meta_bg_size;
+ blk_t numblocks = 0;
+ blk64_t old_desc_blocks;
+ int has_super;
+
+ group_block = ext2fs_group_first_block2(fs, group);
+ if (group_block == 0 && fs->blocksize == 1024)
+ group_block = 1; /* Deal with 1024 blocksize && bigalloc */
+
+ if (ext2fs_has_feature_meta_bg(fs->super))
+ old_desc_blocks = fs->super->s_first_meta_bg;
+ else
+ old_desc_blocks =
+ fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
+
+ has_super = ext2fs_bg_has_super(fs, group);
+
+ if (has_super) {
+ super_blk = group_block;
+ numblocks++;
+ }
+ meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
+ meta_bg = group / meta_bg_size;
+
+ if (!ext2fs_has_feature_meta_bg(fs->super) ||
+ (meta_bg < fs->super->s_first_meta_bg)) {
+ if (has_super) {
+ old_desc_blk = group_block + 1;
+ numblocks += old_desc_blocks;
+ }
+ } else {
+ if (((group % meta_bg_size) == 0) ||
+ ((group % meta_bg_size) == 1) ||
+ ((group % meta_bg_size) == (meta_bg_size-1))) {
+ if (has_super)
+ has_super = 1;
+ new_desc_blk = group_block + has_super;
+ numblocks++;
+ }
+ }
+
+ if (ret_super_blk)
+ *ret_super_blk = super_blk;
+ if (ret_old_desc_blk)
+ *ret_old_desc_blk = old_desc_blk;
+ if (ret_new_desc_blk)
+ *ret_new_desc_blk = new_desc_blk;
+ if (ret_used_blks)
+ *ret_used_blks = numblocks;
+
+ return 0;
+}
+
+/*
+ * This function returns the location of the superblock, block group
+ * descriptors for a given block group. It currently returns the
+ * number of free blocks assuming that inode table and allocation
+ * bitmaps will be in the group. This is not necessarily the case
+ * when the flex_bg feature is enabled, so callers should take care!
+ * It was only really intended for use by mke2fs, and even there it's
+ * not that useful.
+ *
+ * The ext2fs_super_and_bgd_loc2() function is 64-bit block number
+ * capable and returns the number of blocks used by super block and
+ * group descriptors.
+ */
+int ext2fs_super_and_bgd_loc(ext2_filsys fs,
+ dgrp_t group,
+ blk_t *ret_super_blk,
+ blk_t *ret_old_desc_blk,
+ blk_t *ret_new_desc_blk,
+ int *ret_meta_bg)
+{
+ blk64_t ret_super_blk2;
+ blk64_t ret_old_desc_blk2;
+ blk64_t ret_new_desc_blk2;
+ blk_t ret_used_blks;
+ blk_t numblocks;
+ unsigned int meta_bg_size;
+
+ ext2fs_super_and_bgd_loc2(fs, group, &ret_super_blk2,
+ &ret_old_desc_blk2,
+ &ret_new_desc_blk2,
+ &ret_used_blks);
+
+ numblocks = ext2fs_group_blocks_count(fs, group);
+
+ if (ret_super_blk)
+ *ret_super_blk = (blk_t)ret_super_blk2;
+ if (ret_old_desc_blk)
+ *ret_old_desc_blk = (blk_t)ret_old_desc_blk2;
+ if (ret_new_desc_blk)
+ *ret_new_desc_blk = (blk_t)ret_new_desc_blk2;
+ if (ret_meta_bg) {
+ meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
+ *ret_meta_bg = group / meta_bg_size;
+ }
+
+ numblocks -= 2 + fs->inode_blocks_per_group + ret_used_blks;
+
+ return numblocks;
+}
+
+/*
+ * This function forces out the primary superblock. We need to only
+ * write out those fields which we have changed, since if the
+ * filesystem is mounted, it may have changed some of the other
+ * fields.
+ *
+ * It takes as input a superblock which has already been byte swapped
+ * (if necessary).
+ *
+ */
+static errcode_t write_primary_superblock(ext2_filsys fs,
+ struct ext2_super_block *super)
+{
+ __u16 *old_super, *new_super;
+ int check_idx, write_idx, size;
+ errcode_t retval;
+
+ if (!fs->io->manager->write_byte || !fs->orig_super) {
+ fallback:
+ io_channel_set_blksize(fs->io, SUPERBLOCK_OFFSET);
+ retval = io_channel_write_blk64(fs->io, 1, -SUPERBLOCK_SIZE,
+ super);
+ io_channel_set_blksize(fs->io, fs->blocksize);
+ return retval;
+ }
+
+ old_super = (__u16 *) fs->orig_super;
+ new_super = (__u16 *) super;
+
+ for (check_idx = 0; check_idx < SUPERBLOCK_SIZE/2; check_idx++) {
+ if (old_super[check_idx] == new_super[check_idx])
+ continue;
+ write_idx = check_idx;
+ for (check_idx++; check_idx < SUPERBLOCK_SIZE/2; check_idx++)
+ if (old_super[check_idx] == new_super[check_idx])
+ break;
+ size = 2 * (check_idx - write_idx);
+#if 0
+ printf("Writing %d bytes starting at %d\n",
+ size, write_idx*2);
+#endif
+ retval = io_channel_write_byte(fs->io,
+ SUPERBLOCK_OFFSET + (2 * write_idx), size,
+ new_super + write_idx);
+ if (retval == EXT2_ET_UNIMPLEMENTED)
+ goto fallback;
+ if (retval)
+ return retval;
+ }
+ memcpy(fs->orig_super, super, SUPERBLOCK_SIZE);
+ return 0;
+}
+
+
+/*
+ * Updates the revision to EXT2_DYNAMIC_REV
+ */
+void ext2fs_update_dynamic_rev(ext2_filsys fs)
+{
+ struct ext2_super_block *sb = fs->super;
+
+ if (sb->s_rev_level > EXT2_GOOD_OLD_REV)
+ return;
+
+ sb->s_rev_level = EXT2_DYNAMIC_REV;
+ sb->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
+ sb->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
+ /* s_uuid is handled by e2fsck already */
+ /* other fields should be left alone */
+}
+
+static errcode_t write_backup_super(ext2_filsys fs, dgrp_t group,
+ blk64_t group_block,
+ struct ext2_super_block *super_shadow)
+{
+ errcode_t retval;
+ dgrp_t sgrp = group;
+
+ if (sgrp > ((1 << 16) - 1))
+ sgrp = (1 << 16) - 1;
+
+ super_shadow->s_block_group_nr = ext2fs_cpu_to_le16(sgrp);
+
+ retval = ext2fs_superblock_csum_set(fs, super_shadow);
+ if (retval)
+ return retval;
+
+ return io_channel_write_blk64(fs->io, group_block, -SUPERBLOCK_SIZE,
+ super_shadow);
+}
+
+errcode_t ext2fs_flush(ext2_filsys fs)
+{
+ return ext2fs_flush2(fs, 0);
+}
+
+errcode_t ext2fs_flush2(ext2_filsys fs, int flags)
+{
+ dgrp_t i;
+ errcode_t retval;
+ unsigned long fs_state;
+ __u32 feature_incompat;
+ struct ext2_super_block *super_shadow = 0;
+ struct opaque_ext2_group_desc *group_shadow = 0;
+#ifdef WORDS_BIGENDIAN
+ struct ext2_group_desc *gdp;
+ dgrp_t j;
+#endif
+ char *group_ptr;
+ blk64_t old_desc_blocks;
+ struct ext2fs_numeric_progress_struct progress;
+
+ EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+ if ((fs->flags & EXT2_FLAG_SUPER_ONLY) == 0 &&
+ !ext2fs_has_feature_journal_dev(fs->super) &&
+ fs->group_desc == NULL)
+ return EXT2_ET_NO_GDESC;
+
+ fs_state = fs->super->s_state;
+ feature_incompat = fs->super->s_feature_incompat;
+
+ fs->super->s_wtime = fs->now ? fs->now : time(NULL);
+ fs->super->s_block_group_nr = 0;
+
+ /*
+ * If the write_bitmaps() function is present, call it to
+ * flush the bitmaps. This is done this way so that a simple
+ * program that doesn't mess with the bitmaps doesn't need to
+ * drag in the bitmaps.c code.
+ *
+ * Bitmap checksums live in the group descriptor, so the
+ * bitmaps need to be written before the descriptors.
+ */
+ if (fs->write_bitmaps) {
+ retval = fs->write_bitmaps(fs);
+ if (retval)
+ goto errout;
+ }
+
+ /*
+ * Set the state of the FS to be non-valid. (The state has
+ * already been backed up earlier, and will be restored after
+ * we write out the backup superblocks.)
+ */
+ fs->super->s_state &= ~EXT2_VALID_FS;
+ ext2fs_clear_feature_journal_needs_recovery(fs->super);
+
+ /* Byte swap the superblock and the group descriptors if necessary */
+#ifdef WORDS_BIGENDIAN
+ retval = EXT2_ET_NO_MEMORY;
+ retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super_shadow);
+ if (retval)
+ goto errout;
+ memcpy(super_shadow, fs->super, sizeof(struct ext2_super_block));
+ ext2fs_swap_super(super_shadow);
+
+ if (((fs->flags & EXT2_FLAG_SUPER_ONLY) == 0) &&
+ !ext2fs_has_feature_journal_dev(fs->super)) {
+ retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize,
+ &group_shadow);
+ if (retval)
+ goto errout;
+ memcpy(group_shadow, fs->group_desc, (size_t) fs->blocksize *
+ fs->desc_blocks);
+
+ for (j = 0; j < fs->group_desc_count; j++) {
+ gdp = ext2fs_group_desc(fs, group_shadow, j);
+ ext2fs_swap_group_desc2(fs, gdp);
+ }
+ }
+#else
+ super_shadow = fs->super;
+ group_shadow = fs->group_desc;
+#endif
+
+ /*
+ * If this is an external journal device, don't write out the
+ * block group descriptors or any of the backup superblocks
+ */
+ if (ext2fs_has_feature_journal_dev(fs->super))
+ goto write_primary_superblock_only;
+
+ /*
+ * Write out the master group descriptors, and the backup
+ * superblocks and group descriptors.
+ */
+ group_ptr = (char *) group_shadow;
+ if (ext2fs_has_feature_meta_bg(fs->super)) {
+ old_desc_blocks = fs->super->s_first_meta_bg;
+ if (old_desc_blocks > fs->desc_blocks)
+ old_desc_blocks = fs->desc_blocks;
+ } else
+ old_desc_blocks = fs->desc_blocks;
+
+ if (fs->progress_ops && fs->progress_ops->init)
+ (fs->progress_ops->init)(fs, &progress, NULL,
+ fs->group_desc_count);
+
+
+ for (i = 0; i < fs->group_desc_count; i++) {
+ blk64_t super_blk, old_desc_blk, new_desc_blk;
+
+ if (fs->progress_ops && fs->progress_ops->update)
+ (fs->progress_ops->update)(fs, &progress, i);
+ ext2fs_super_and_bgd_loc2(fs, i, &super_blk, &old_desc_blk,
+ &new_desc_blk, 0);
+
+ if (!(fs->flags & EXT2_FLAG_MASTER_SB_ONLY) &&i && super_blk) {
+ retval = write_backup_super(fs, i, super_blk,
+ super_shadow);
+ if (retval)
+ goto errout;
+ }
+ if (fs->flags & EXT2_FLAG_SUPER_ONLY)
+ continue;
+ if ((old_desc_blk) &&
+ (!(fs->flags & EXT2_FLAG_MASTER_SB_ONLY) || (i == 0))) {
+ retval = io_channel_write_blk64(fs->io,
+ old_desc_blk, old_desc_blocks, group_ptr);
+ if (retval)
+ goto errout;
+ }
+ if (new_desc_blk) {
+ int meta_bg = i / EXT2_DESC_PER_BLOCK(fs->super);
+
+ retval = io_channel_write_blk64(fs->io, new_desc_blk,
+ 1, group_ptr + (meta_bg*fs->blocksize));
+ if (retval)
+ goto errout;
+ }
+ }
+
+ if (fs->progress_ops && fs->progress_ops->close)
+ (fs->progress_ops->close)(fs, &progress, NULL);
+
+write_primary_superblock_only:
+ /*
+ * Write out master superblock. This has to be done
+ * separately, since it is located at a fixed location
+ * (SUPERBLOCK_OFFSET). We flush all other pending changes
+ * out to disk first, just to avoid a race condition with an
+ * insy-tinsy window....
+ */
+
+ fs->super->s_block_group_nr = 0;
+ fs->super->s_state = fs_state;
+ fs->super->s_feature_incompat = feature_incompat;
+#ifdef WORDS_BIGENDIAN
+ *super_shadow = *fs->super;
+ ext2fs_swap_super(super_shadow);
+#endif
+
+ retval = ext2fs_superblock_csum_set(fs, super_shadow);
+ if (retval)
+ return retval;
+
+ if (!(flags & EXT2_FLAG_FLUSH_NO_SYNC)) {
+ retval = io_channel_flush(fs->io);
+ if (retval)
+ goto errout;
+ }
+ retval = write_primary_superblock(fs, super_shadow);
+ if (retval)
+ goto errout;
+
+ fs->flags &= ~EXT2_FLAG_DIRTY;
+
+ if (!(flags & EXT2_FLAG_FLUSH_NO_SYNC)) {
+ retval = io_channel_flush(fs->io);
+ if (retval)
+ goto errout;
+ }
+errout:
+ fs->super->s_state = fs_state;
+#ifdef WORDS_BIGENDIAN
+ if (super_shadow)
+ ext2fs_free_mem(&super_shadow);
+ if (group_shadow)
+ ext2fs_free_mem(&group_shadow);
+#endif
+ return retval;
+}
+
+errcode_t ext2fs_close_free(ext2_filsys *fs_ptr)
+{
+ errcode_t ret;
+ ext2_filsys fs = *fs_ptr;
+
+ ret = ext2fs_close2(fs, 0);
+ if (ret)
+ ext2fs_free(fs);
+ *fs_ptr = NULL;
+ return ret;
+}
+
+errcode_t ext2fs_close(ext2_filsys fs)
+{
+ return ext2fs_close2(fs, 0);
+}
+
+errcode_t ext2fs_close2(ext2_filsys fs, int flags)
+{
+ errcode_t retval;
+ int meta_blks;
+ io_stats stats = 0;
+
+ EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+ if (fs->write_bitmaps) {
+ retval = fs->write_bitmaps(fs);
+ if (retval)
+ return retval;
+ }
+ if (fs->super->s_kbytes_written &&
+ fs->io->manager->get_stats)
+ fs->io->manager->get_stats(fs->io, &stats);
+ if (stats && stats->bytes_written && (fs->flags & EXT2_FLAG_RW)) {
+ fs->super->s_kbytes_written += stats->bytes_written >> 10;
+ meta_blks = fs->desc_blocks + 1;
+ if (!(fs->flags & EXT2_FLAG_SUPER_ONLY))
+ fs->super->s_kbytes_written += meta_blks /
+ (fs->blocksize / 1024);
+ if ((fs->flags & EXT2_FLAG_DIRTY) == 0)
+ fs->flags |= EXT2_FLAG_SUPER_ONLY | EXT2_FLAG_DIRTY;
+ }
+ if (fs->flags & EXT2_FLAG_DIRTY) {
+ retval = ext2fs_flush2(fs, flags);
+ if (retval)
+ return retval;
+ }
+
+ retval = ext2fs_mmp_stop(fs);
+ if (retval)
+ return retval;
+
+ ext2fs_free(fs);
+ return 0;
+}
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-09 22:35:09 +0000