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-rw-r--r--lib/ext2fs/alloc.c554
1 files changed, 554 insertions, 0 deletions
diff --git a/lib/ext2fs/alloc.c b/lib/ext2fs/alloc.c
new file mode 100644
index 0000000..3fd9216
--- /dev/null
+++ b/lib/ext2fs/alloc.c
@@ -0,0 +1,554 @@
+/*
+ * alloc.c --- allocate new inodes, blocks for ext2fs
+ *
+ * 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>
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#include "ext2_fs.h"
+#include "ext2fs.h"
+
+#define min(a, b) ((a) < (b) ? (a) : (b))
+
+#undef DEBUG
+
+#ifdef DEBUG
+# define dbg_printf(f, a...) do {printf(f, ## a); fflush(stdout); } while (0)
+#else
+# define dbg_printf(f, a...)
+#endif
+
+/*
+ * Clear the uninit block bitmap flag if necessary
+ */
+void ext2fs_clear_block_uninit(ext2_filsys fs, dgrp_t group)
+{
+ if (group >= fs->group_desc_count ||
+ !ext2fs_has_group_desc_csum(fs) ||
+ !(ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT)))
+ return;
+
+ /* uninit block bitmaps are now initialized in read_bitmaps() */
+
+ ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT);
+ ext2fs_group_desc_csum_set(fs, group);
+ ext2fs_mark_super_dirty(fs);
+ ext2fs_mark_bb_dirty(fs);
+}
+
+/*
+ * Check for uninit inode bitmaps and deal with them appropriately
+ */
+static void check_inode_uninit(ext2_filsys fs, ext2fs_inode_bitmap map,
+ dgrp_t group)
+{
+ ext2_ino_t i, ino;
+
+ if (group >= fs->group_desc_count ||
+ !ext2fs_has_group_desc_csum(fs) ||
+ !(ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT)))
+ return;
+
+ ino = (group * fs->super->s_inodes_per_group) + 1;
+ for (i=0; i < fs->super->s_inodes_per_group; i++, ino++)
+ ext2fs_fast_unmark_inode_bitmap2(map, ino);
+
+ ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT);
+ /* Mimics what the kernel does */
+ ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT);
+ ext2fs_group_desc_csum_set(fs, group);
+ ext2fs_mark_ib_dirty(fs);
+ ext2fs_mark_super_dirty(fs);
+}
+
+/*
+ * Right now, just search forward from the parent directory's block
+ * group to find the next free inode.
+ *
+ * Should have a special policy for directories.
+ */
+errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir,
+ int mode EXT2FS_ATTR((unused)),
+ ext2fs_inode_bitmap map, ext2_ino_t *ret)
+{
+ ext2_ino_t start_inode = 0;
+ ext2_ino_t i, ino_in_group, upto, first_zero;
+ errcode_t retval;
+ dgrp_t group;
+
+ EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+ if (!map)
+ map = fs->inode_map;
+ if (!map)
+ return EXT2_ET_NO_INODE_BITMAP;
+
+ if (dir > 0) {
+ group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super);
+ start_inode = (group * EXT2_INODES_PER_GROUP(fs->super)) + 1;
+ }
+ if (start_inode < EXT2_FIRST_INODE(fs->super))
+ start_inode = EXT2_FIRST_INODE(fs->super);
+ if (start_inode > fs->super->s_inodes_count)
+ return EXT2_ET_INODE_ALLOC_FAIL;
+ i = start_inode;
+ do {
+ ino_in_group = (i - 1) % EXT2_INODES_PER_GROUP(fs->super);
+ group = (i - 1) / EXT2_INODES_PER_GROUP(fs->super);
+
+ check_inode_uninit(fs, map, group);
+ upto = i + (EXT2_INODES_PER_GROUP(fs->super) - ino_in_group);
+ if (i < start_inode && upto >= start_inode)
+ upto = start_inode - 1;
+ if (upto > fs->super->s_inodes_count)
+ upto = fs->super->s_inodes_count;
+
+ retval = ext2fs_find_first_zero_inode_bitmap2(map, i, upto,
+ &first_zero);
+ if (retval == 0) {
+ i = first_zero;
+ break;
+ }
+ if (retval != ENOENT)
+ return EXT2_ET_INODE_ALLOC_FAIL;
+ i = upto + 1;
+ if (i > fs->super->s_inodes_count)
+ i = EXT2_FIRST_INODE(fs->super);
+ } while (i != start_inode);
+
+ if (ext2fs_test_inode_bitmap2(map, i))
+ return EXT2_ET_INODE_ALLOC_FAIL;
+ *ret = i;
+ return 0;
+}
+
+/*
+ * Stupid algorithm --- we now just search forward starting from the
+ * goal. Should put in a smarter one someday....
+ */
+errcode_t ext2fs_new_block3(ext2_filsys fs, blk64_t goal,
+ ext2fs_block_bitmap map, blk64_t *ret,
+ struct blk_alloc_ctx *ctx)
+{
+ errcode_t retval;
+ blk64_t b = 0;
+ errcode_t (*gab)(ext2_filsys fs, blk64_t goal, blk64_t *ret);
+ errcode_t (*gab2)(ext2_filsys, blk64_t, blk64_t *,
+ struct blk_alloc_ctx *);
+
+ EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+ if (!map) {
+ /*
+ * In case there are clients out there whose get_alloc_block
+ * handlers call ext2fs_new_block2 with a NULL block map,
+ * temporarily swap out the function pointer so that we don't
+ * end up in an infinite loop.
+ */
+ if (fs->get_alloc_block2) {
+ gab2 = fs->get_alloc_block2;
+ fs->get_alloc_block2 = NULL;
+ retval = gab2(fs, goal, &b, ctx);
+ fs->get_alloc_block2 = gab2;
+ goto allocated;
+ } else if (fs->get_alloc_block) {
+ gab = fs->get_alloc_block;
+ fs->get_alloc_block = NULL;
+ retval = gab(fs, goal, &b);
+ fs->get_alloc_block = gab;
+ goto allocated;
+ }
+ }
+ if (!map)
+ map = fs->block_map;
+ if (!map)
+ return EXT2_ET_NO_BLOCK_BITMAP;
+ if (!goal || (goal >= ext2fs_blocks_count(fs->super)))
+ goal = fs->super->s_first_data_block;
+ goal &= ~EXT2FS_CLUSTER_MASK(fs);
+
+ retval = ext2fs_find_first_zero_block_bitmap2(map,
+ goal, ext2fs_blocks_count(fs->super) - 1, &b);
+ if ((retval == ENOENT) && (goal != fs->super->s_first_data_block))
+ retval = ext2fs_find_first_zero_block_bitmap2(map,
+ fs->super->s_first_data_block, goal - 1, &b);
+allocated:
+ if (retval == ENOENT)
+ return EXT2_ET_BLOCK_ALLOC_FAIL;
+ if (retval)
+ return retval;
+
+ ext2fs_clear_block_uninit(fs, ext2fs_group_of_blk2(fs, b));
+ *ret = b;
+ return 0;
+}
+
+errcode_t ext2fs_new_block2(ext2_filsys fs, blk64_t goal,
+ ext2fs_block_bitmap map, blk64_t *ret)
+{
+ return ext2fs_new_block3(fs, goal, map, ret, NULL);
+}
+
+errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal,
+ ext2fs_block_bitmap map, blk_t *ret)
+{
+ errcode_t retval;
+ blk64_t val;
+ retval = ext2fs_new_block2(fs, goal, map, &val);
+ if (!retval)
+ *ret = (blk_t) val;
+ return retval;
+}
+
+/*
+ * This function zeros out the allocated block, and updates all of the
+ * appropriate filesystem records.
+ */
+errcode_t ext2fs_alloc_block3(ext2_filsys fs, blk64_t goal, char *block_buf,
+ blk64_t *ret, struct blk_alloc_ctx *ctx)
+{
+ errcode_t retval;
+ blk64_t block;
+
+ if (fs->get_alloc_block2) {
+ retval = (fs->get_alloc_block2)(fs, goal, &block, ctx);
+ if (retval)
+ goto fail;
+ } else if (fs->get_alloc_block) {
+ retval = (fs->get_alloc_block)(fs, goal, &block);
+ if (retval)
+ goto fail;
+ } else {
+ if (!fs->block_map) {
+ retval = ext2fs_read_block_bitmap(fs);
+ if (retval)
+ goto fail;
+ }
+
+ retval = ext2fs_new_block3(fs, goal, 0, &block, ctx);
+ if (retval)
+ goto fail;
+ }
+
+ if (block_buf) {
+ memset(block_buf, 0, fs->blocksize);
+ retval = io_channel_write_blk64(fs->io, block, 1, block_buf);
+ } else
+ retval = ext2fs_zero_blocks2(fs, block, 1, NULL, NULL);
+ if (retval)
+ goto fail;
+
+ ext2fs_block_alloc_stats2(fs, block, +1);
+ *ret = block;
+
+fail:
+ return retval;
+}
+
+errcode_t ext2fs_alloc_block2(ext2_filsys fs, blk64_t goal,
+ char *block_buf, blk64_t *ret)
+{
+ return ext2fs_alloc_block3(fs, goal, block_buf, ret, NULL);
+}
+
+errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
+ char *block_buf, blk_t *ret)
+{
+ errcode_t retval;
+ blk64_t ret64, goal64 = goal;
+ retval = ext2fs_alloc_block3(fs, goal64, block_buf, &ret64, NULL);
+ if (!retval)
+ *ret = (blk_t)ret64;
+ return retval;
+}
+
+errcode_t ext2fs_get_free_blocks2(ext2_filsys fs, blk64_t start, blk64_t finish,
+ int num, ext2fs_block_bitmap map, blk64_t *ret)
+{
+ blk64_t b = start;
+ int c_ratio;
+
+ EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+ if (!map)
+ map = fs->block_map;
+ if (!map)
+ return EXT2_ET_NO_BLOCK_BITMAP;
+ if (!b)
+ b = fs->super->s_first_data_block;
+ if (!finish)
+ finish = start;
+ if (!num)
+ num = 1;
+ c_ratio = 1 << ext2fs_get_bitmap_granularity(map);
+ b &= ~(c_ratio - 1);
+ finish &= ~(c_ratio -1);
+ do {
+ if (b + num - 1 >= ext2fs_blocks_count(fs->super)) {
+ if (finish > start)
+ return EXT2_ET_BLOCK_ALLOC_FAIL;
+ b = fs->super->s_first_data_block;
+ }
+ if (ext2fs_fast_test_block_bitmap_range2(map, b, num)) {
+ *ret = b;
+ return 0;
+ }
+ b += c_ratio;
+ } while (b != finish);
+ return EXT2_ET_BLOCK_ALLOC_FAIL;
+}
+
+errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish,
+ int num, ext2fs_block_bitmap map, blk_t *ret)
+{
+ errcode_t retval;
+ blk64_t val;
+ retval = ext2fs_get_free_blocks2(fs, start, finish, num, map, &val);
+ if(!retval)
+ *ret = (blk_t) val;
+ return retval;
+}
+
+void ext2fs_set_alloc_block_callback(ext2_filsys fs,
+ errcode_t (*func)(ext2_filsys fs,
+ blk64_t goal,
+ blk64_t *ret),
+ errcode_t (**old)(ext2_filsys fs,
+ blk64_t goal,
+ blk64_t *ret))
+{
+ if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS)
+ return;
+
+ if (old)
+ *old = fs->get_alloc_block;
+
+ fs->get_alloc_block = func;
+}
+
+blk64_t ext2fs_find_inode_goal(ext2_filsys fs, ext2_ino_t ino,
+ struct ext2_inode *inode, blk64_t lblk)
+{
+ dgrp_t group;
+ __u8 log_flex;
+ struct ext2fs_extent extent;
+ ext2_extent_handle_t handle = NULL;
+ errcode_t err;
+
+ /* Make sure data stored in inode->i_block is neither fast symlink nor
+ * inline data.
+ */
+ if (inode == NULL || ext2fs_is_fast_symlink(inode) ||
+ inode->i_flags & EXT4_INLINE_DATA_FL)
+ goto no_blocks;
+
+ if (inode->i_flags & EXT4_EXTENTS_FL) {
+ err = ext2fs_extent_open2(fs, ino, inode, &handle);
+ if (err)
+ goto no_blocks;
+ err = ext2fs_extent_goto2(handle, 0, lblk);
+ if (err)
+ goto no_blocks;
+ err = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
+ if (err)
+ goto no_blocks;
+ ext2fs_extent_free(handle);
+ return extent.e_pblk + (lblk - extent.e_lblk);
+ }
+
+ /* block mapped file; see if block zero is mapped? */
+ if (inode->i_block[0])
+ return inode->i_block[0];
+
+no_blocks:
+ ext2fs_extent_free(handle);
+ log_flex = fs->super->s_log_groups_per_flex;
+ group = ext2fs_group_of_ino(fs, ino);
+ if (log_flex)
+ group = group & ~((1 << (log_flex)) - 1);
+ return ext2fs_group_first_block2(fs, group);
+}
+
+/*
+ * Starting at _goal_, scan around the filesystem to find a run of free blocks
+ * that's at least _len_ blocks long. Possible flags:
+ * - EXT2_NEWRANGE_EXACT_GOAL: The range of blocks must start at _goal_.
+ * - EXT2_NEWRANGE_MIN_LENGTH: do not return a allocation shorter than _len_.
+ * - EXT2_NEWRANGE_ZERO_BLOCKS: Zero blocks pblk to pblk+plen before returning.
+ *
+ * The starting block is returned in _pblk_ and the length is returned via
+ * _plen_. The blocks are not marked in the bitmap; the caller must mark
+ * however much of the returned run they actually use, hopefully via
+ * ext2fs_block_alloc_stats_range().
+ *
+ * This function can return a range that is longer than what was requested.
+ */
+errcode_t ext2fs_new_range(ext2_filsys fs, int flags, blk64_t goal,
+ blk64_t len, ext2fs_block_bitmap map, blk64_t *pblk,
+ blk64_t *plen)
+{
+ errcode_t retval;
+ blk64_t start, end, b;
+ int looped = 0;
+ blk64_t max_blocks = ext2fs_blocks_count(fs->super);
+ errcode_t (*nrf)(ext2_filsys fs, int flags, blk64_t goal,
+ blk64_t len, blk64_t *pblk, blk64_t *plen);
+
+ dbg_printf("%s: flags=0x%x goal=%llu len=%llu\n", __func__, flags,
+ goal, len);
+ EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+ if (len == 0 || (flags & ~EXT2_NEWRANGE_ALL_FLAGS))
+ return EXT2_ET_INVALID_ARGUMENT;
+
+ if (!map && fs->new_range) {
+ /*
+ * In case there are clients out there whose new_range
+ * handlers call ext2fs_new_range with a NULL block map,
+ * temporarily swap out the function pointer so that we don't
+ * end up in an infinite loop.
+ */
+ nrf = fs->new_range;
+ fs->new_range = NULL;
+ retval = nrf(fs, flags, goal, len, pblk, plen);
+ fs->new_range = nrf;
+ if (retval)
+ return retval;
+ start = *pblk;
+ end = *pblk + *plen;
+ goto allocated;
+ }
+ if (!map)
+ map = fs->block_map;
+ if (!map)
+ return EXT2_ET_NO_BLOCK_BITMAP;
+ if (!goal || goal >= ext2fs_blocks_count(fs->super))
+ goal = fs->super->s_first_data_block;
+
+ start = goal;
+ while (!looped || start <= goal) {
+ retval = ext2fs_find_first_zero_block_bitmap2(map, start,
+ max_blocks - 1,
+ &start);
+ if (retval == ENOENT) {
+ /*
+ * If there are no free blocks beyond the starting
+ * point, try scanning the whole filesystem, unless the
+ * user told us only to allocate from _goal_, or if
+ * we're already scanning the whole filesystem.
+ */
+ if (flags & EXT2_NEWRANGE_FIXED_GOAL ||
+ start == fs->super->s_first_data_block)
+ goto fail;
+ start = fs->super->s_first_data_block;
+ continue;
+ } else if (retval)
+ goto errout;
+
+ if (flags & EXT2_NEWRANGE_FIXED_GOAL && start != goal)
+ goto fail;
+
+ b = min(start + len - 1, max_blocks - 1);
+ retval = ext2fs_find_first_set_block_bitmap2(map, start, b,
+ &end);
+ if (retval == ENOENT)
+ end = b + 1;
+ else if (retval)
+ goto errout;
+
+ if (!(flags & EXT2_NEWRANGE_MIN_LENGTH) ||
+ (end - start) >= len) {
+ /* Success! */
+ *pblk = start;
+ *plen = end - start;
+ dbg_printf("%s: new_range goal=%llu--%llu "
+ "blk=%llu--%llu %llu\n",
+ __func__, goal, goal + len - 1,
+ *pblk, *pblk + *plen - 1, *plen);
+allocated:
+ for (b = start; b < end;
+ b += fs->super->s_blocks_per_group)
+ ext2fs_clear_block_uninit(fs,
+ ext2fs_group_of_blk2(fs, b));
+ return 0;
+ }
+
+ if (flags & EXT2_NEWRANGE_FIXED_GOAL)
+ goto fail;
+ start = end;
+ if (start >= max_blocks) {
+ if (looped)
+ goto fail;
+ looped = 1;
+ start = fs->super->s_first_data_block;
+ }
+ }
+
+fail:
+ retval = EXT2_ET_BLOCK_ALLOC_FAIL;
+errout:
+ return retval;
+}
+
+void ext2fs_set_new_range_callback(ext2_filsys fs,
+ errcode_t (*func)(ext2_filsys fs, int flags, blk64_t goal,
+ blk64_t len, blk64_t *pblk, blk64_t *plen),
+ errcode_t (**old)(ext2_filsys fs, int flags, blk64_t goal,
+ blk64_t len, blk64_t *pblk, blk64_t *plen))
+{
+ if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS)
+ return;
+
+ if (old)
+ *old = fs->new_range;
+
+ fs->new_range = func;
+}
+
+errcode_t ext2fs_alloc_range(ext2_filsys fs, int flags, blk64_t goal,
+ blk_t len, blk64_t *ret)
+{
+ int newr_flags = EXT2_NEWRANGE_MIN_LENGTH;
+ errcode_t retval;
+ blk64_t plen;
+
+ EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+ if (len == 0 || (flags & ~EXT2_ALLOCRANGE_ALL_FLAGS))
+ return EXT2_ET_INVALID_ARGUMENT;
+
+ if (flags & EXT2_ALLOCRANGE_FIXED_GOAL)
+ newr_flags |= EXT2_NEWRANGE_FIXED_GOAL;
+
+ retval = ext2fs_new_range(fs, newr_flags, goal, len, NULL, ret, &plen);
+ if (retval)
+ return retval;
+
+ if (plen < len)
+ return EXT2_ET_BLOCK_ALLOC_FAIL;
+
+ if (flags & EXT2_ALLOCRANGE_ZERO_BLOCKS) {
+ retval = ext2fs_zero_blocks2(fs, *ret, len, NULL, NULL);
+ if (retval)
+ return retval;
+ }
+
+ ext2fs_block_alloc_stats_range(fs, *ret, len, +1);
+ return retval;
+}