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authorbigbiff bigbiff <bigbiff@teamw.in>2013-01-28 14:14:25 +0100
committerDees_Troy <dees_troy@teamw.in>2013-01-28 16:24:04 +0100
commitca829c4b81bfcdb7ea676694c5cfd0b79ccbb646 (patch)
treec182c6075b31a4536edcfa41f290b5e7e6caa8c2 /exfat/cluster.c
parentMerge "Pull fix for exFAT from original source" into twrp2.4 (diff)
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Diffstat (limited to '')
-rw-r--r--exfat/cluster.c428
1 files changed, 0 insertions, 428 deletions
diff --git a/exfat/cluster.c b/exfat/cluster.c
deleted file mode 100644
index 6b0303df8..000000000
--- a/exfat/cluster.c
+++ /dev/null
@@ -1,428 +0,0 @@
-/*
- cluster.c (03.09.09)
- exFAT file system implementation library.
-
- Copyright (C) 2010-2012 Andrew Nayenko
-
- This program is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#include "exfat.h"
-#include <errno.h>
-#include <string.h>
-
-/*
- * Sector to absolute offset.
- */
-static off64_t s2o(const struct exfat* ef, off64_t sector)
-{
- return sector << ef->sb->sector_bits;
-}
-
-/*
- * Cluster to sector.
- */
-static off64_t c2s(const struct exfat* ef, cluster_t cluster)
-{
- if (cluster < EXFAT_FIRST_DATA_CLUSTER)
- exfat_bug("invalid cluster number %u", cluster);
- return le32_to_cpu(ef->sb->cluster_sector_start) +
- ((off64_t) (cluster - EXFAT_FIRST_DATA_CLUSTER) << ef->sb->spc_bits);
-}
-
-/*
- * Cluster to absolute offset.
- */
-off64_t exfat_c2o(const struct exfat* ef, cluster_t cluster)
-{
- return s2o(ef, c2s(ef, cluster));
-}
-
-/*
- * Sector to cluster.
- */
-static cluster_t s2c(const struct exfat* ef, off64_t sector)
-{
- return ((sector - le32_to_cpu(ef->sb->cluster_sector_start)) >>
- ef->sb->spc_bits) + EXFAT_FIRST_DATA_CLUSTER;
-}
-
-/*
- * Size in bytes to size in clusters (rounded upwards).
- */
-static uint32_t bytes2clusters(const struct exfat* ef, uint64_t bytes)
-{
- uint64_t cluster_size = CLUSTER_SIZE(*ef->sb);
- return (bytes + cluster_size - 1) / cluster_size;
-}
-
-cluster_t exfat_next_cluster(const struct exfat* ef,
- const struct exfat_node* node, cluster_t cluster)
-{
- le32_t next;
- off64_t fat_offset;
-
- if (cluster < EXFAT_FIRST_DATA_CLUSTER)
- exfat_bug("bad cluster 0x%x", cluster);
-
- if (IS_CONTIGUOUS(*node))
- return cluster + 1;
- fat_offset = s2o(ef, le32_to_cpu(ef->sb->fat_sector_start))
- + cluster * sizeof(cluster_t);
- exfat_pread(ef->dev, &next, sizeof(next), fat_offset);
- return le32_to_cpu(next);
-}
-
-cluster_t exfat_advance_cluster(const struct exfat* ef,
- struct exfat_node* node, uint32_t count)
-{
- uint32_t i;
-
- if (node->fptr_index > count)
- {
- node->fptr_index = 0;
- node->fptr_cluster = node->start_cluster;
- }
-
- for (i = node->fptr_index; i < count; i++)
- {
- node->fptr_cluster = exfat_next_cluster(ef, node, node->fptr_cluster);
- if (CLUSTER_INVALID(node->fptr_cluster))
- break; /* the caller should handle this and print appropriate
- error message */
- }
- node->fptr_index = count;
- return node->fptr_cluster;
-}
-
-static cluster_t find_bit_and_set(uint8_t* bitmap, size_t start, size_t end)
-{
- const size_t start_index = start / 8;
- const size_t end_index = DIV_ROUND_UP(end, 8);
- size_t i;
- size_t c;
-
- for (i = start_index; i < end_index; i++)
- {
- if (bitmap[i] == 0xff)
- continue;
- for (c = MAX(i * 8, start); c < MIN((i + 1) * 8, end); c++)
- if (BMAP_GET(bitmap, c) == 0)
- {
- BMAP_SET(bitmap, c);
- return c + EXFAT_FIRST_DATA_CLUSTER;
- }
- }
- return EXFAT_CLUSTER_END;
-}
-
-void exfat_flush_cmap(struct exfat* ef)
-{
- exfat_pwrite(ef->dev, ef->cmap.chunk, (ef->cmap.chunk_size + 7) / 8,
- exfat_c2o(ef, ef->cmap.start_cluster));
- ef->cmap.dirty = false;
-}
-
-static void set_next_cluster(const struct exfat* ef, int contiguous,
- cluster_t current, cluster_t next)
-{
- off64_t fat_offset;
- le32_t next_le32;
-
- if (contiguous)
- return;
- fat_offset = s2o(ef, le32_to_cpu(ef->sb->fat_sector_start))
- + current * sizeof(cluster_t);
- next_le32 = cpu_to_le32(next);
- exfat_pwrite(ef->dev, &next_le32, sizeof(next_le32), fat_offset);
-}
-
-static cluster_t allocate_cluster(struct exfat* ef, cluster_t hint)
-{
- cluster_t cluster;
-
- hint -= EXFAT_FIRST_DATA_CLUSTER;
- if (hint >= ef->cmap.chunk_size)
- hint = 0;
-
- cluster = find_bit_and_set(ef->cmap.chunk, hint, ef->cmap.chunk_size);
- if (cluster == EXFAT_CLUSTER_END)
- cluster = find_bit_and_set(ef->cmap.chunk, 0, hint);
- if (cluster == EXFAT_CLUSTER_END)
- {
- exfat_error("no free space left");
- return EXFAT_CLUSTER_END;
- }
-
- ef->cmap.dirty = true;
- return cluster;
-}
-
-static void free_cluster(struct exfat* ef, cluster_t cluster)
-{
- if (CLUSTER_INVALID(cluster))
- exfat_bug("freeing invalid cluster 0x%x", cluster);
- if (cluster - EXFAT_FIRST_DATA_CLUSTER >= ef->cmap.size)
- exfat_bug("freeing non-existing cluster 0x%x (0x%x)", cluster,
- ef->cmap.size);
-
- BMAP_CLR(ef->cmap.chunk, cluster - EXFAT_FIRST_DATA_CLUSTER);
- ef->cmap.dirty = true;
-}
-
-static void make_noncontiguous(const struct exfat* ef, cluster_t first,
- cluster_t last)
-{
- cluster_t c;
-
- for (c = first; c < last; c++)
- set_next_cluster(ef, 0, c, c + 1);
-}
-
-static int shrink_file(struct exfat* ef, struct exfat_node* node,
- uint32_t current, uint32_t difference);
-
-static int grow_file(struct exfat* ef, struct exfat_node* node,
- uint32_t current, uint32_t difference)
-{
- cluster_t previous;
- cluster_t next;
- uint32_t allocated = 0;
-
- if (difference == 0)
- exfat_bug("zero clusters count passed");
-
- if (node->start_cluster != EXFAT_CLUSTER_FREE)
- {
- /* get the last cluster of the file */
- previous = exfat_advance_cluster(ef, node, current - 1);
- if (CLUSTER_INVALID(previous))
- {
- exfat_error("invalid cluster 0x%x while growing", previous);
- return -EIO;
- }
- }
- else
- {
- if (node->fptr_index != 0)
- exfat_bug("non-zero pointer index (%u)", node->fptr_index);
- /* file does not have clusters (i.e. is empty), allocate
- the first one for it */
- previous = allocate_cluster(ef, 0);
- if (CLUSTER_INVALID(previous))
- return -ENOSPC;
- node->fptr_cluster = node->start_cluster = previous;
- allocated = 1;
- /* file consists of only one cluster, so it's contiguous */
- node->flags |= EXFAT_ATTRIB_CONTIGUOUS;
- }
-
- while (allocated < difference)
- {
- next = allocate_cluster(ef, previous + 1);
- if (CLUSTER_INVALID(next))
- {
- if (allocated != 0)
- shrink_file(ef, node, current + allocated, allocated);
- return -ENOSPC;
- }
- if (next != previous - 1 && IS_CONTIGUOUS(*node))
- {
- /* it's a pity, but we are not able to keep the file contiguous
- anymore */
- make_noncontiguous(ef, node->start_cluster, previous);
- node->flags &= ~EXFAT_ATTRIB_CONTIGUOUS;
- node->flags |= EXFAT_ATTRIB_DIRTY;
- }
- set_next_cluster(ef, IS_CONTIGUOUS(*node), previous, next);
- previous = next;
- allocated++;
- }
-
- set_next_cluster(ef, IS_CONTIGUOUS(*node), previous, EXFAT_CLUSTER_END);
- return 0;
-}
-
-static int shrink_file(struct exfat* ef, struct exfat_node* node,
- uint32_t current, uint32_t difference)
-{
- cluster_t previous;
- cluster_t next;
-
- if (difference == 0)
- exfat_bug("zero difference passed");
- if (node->start_cluster == EXFAT_CLUSTER_FREE)
- exfat_bug("unable to shrink empty file (%u clusters)", current);
- if (current < difference)
- exfat_bug("file underflow (%u < %u)", current, difference);
-
- /* crop the file */
- if (current > difference)
- {
- cluster_t last = exfat_advance_cluster(ef, node,
- current - difference - 1);
- if (CLUSTER_INVALID(last))
- {
- exfat_error("invalid cluster 0x%x while shrinking", last);
- return -EIO;
- }
- previous = exfat_next_cluster(ef, node, last);
- set_next_cluster(ef, IS_CONTIGUOUS(*node), last, EXFAT_CLUSTER_END);
- }
- else
- {
- previous = node->start_cluster;
- node->start_cluster = EXFAT_CLUSTER_FREE;
- }
- node->fptr_index = 0;
- node->fptr_cluster = node->start_cluster;
-
- /* free remaining clusters */
- while (difference--)
- {
- if (CLUSTER_INVALID(previous))
- {
- exfat_error("invalid cluster 0x%x while freeing after shrink",
- previous);
- return -EIO;
- }
- next = exfat_next_cluster(ef, node, previous);
- set_next_cluster(ef, IS_CONTIGUOUS(*node), previous,
- EXFAT_CLUSTER_FREE);
- free_cluster(ef, previous);
- previous = next;
- }
- return 0;
-}
-
-static void erase_raw(struct exfat* ef, size_t size, off64_t offset)
-{
- exfat_pwrite(ef->dev, ef->zero_cluster, size, offset);
-}
-
-static int erase_range(struct exfat* ef, struct exfat_node* node,
- uint64_t begin, uint64_t end)
-{
- uint64_t cluster_boundary;
- cluster_t cluster;
-
- if (begin >= end)
- return 0;
-
- cluster_boundary = (begin | (CLUSTER_SIZE(*ef->sb) - 1)) + 1;
- cluster = exfat_advance_cluster(ef, node,
- begin / CLUSTER_SIZE(*ef->sb));
- if (CLUSTER_INVALID(cluster))
- {
- exfat_error("invalid cluster 0x%x while erasing", cluster);
- return -EIO;
- }
- /* erase from the beginning to the closest cluster boundary */
- erase_raw(ef, MIN(cluster_boundary, end) - begin,
- exfat_c2o(ef, cluster) + begin % CLUSTER_SIZE(*ef->sb));
- /* erase whole clusters */
- while (cluster_boundary < end)
- {
- cluster = exfat_next_cluster(ef, node, cluster);
- /* the cluster cannot be invalid because we have just allocated it */
- if (CLUSTER_INVALID(cluster))
- exfat_bug("invalid cluster 0x%x after allocation", cluster);
- erase_raw(ef, CLUSTER_SIZE(*ef->sb), exfat_c2o(ef, cluster));
- cluster_boundary += CLUSTER_SIZE(*ef->sb);
- }
- return 0;
-}
-
-int exfat_truncate(struct exfat* ef, struct exfat_node* node, uint64_t size)
-{
- uint32_t c1 = bytes2clusters(ef, node->size);
- uint32_t c2 = bytes2clusters(ef, size);
- int rc = 0;
-
- if (node->references == 0 && node->parent)
- exfat_bug("no references, node changes can be lost");
-
- if (node->size == size)
- return 0;
-
- if (c1 < c2)
- rc = grow_file(ef, node, c1, c2 - c1);
- else if (c1 > c2)
- rc = shrink_file(ef, node, c1, c1 - c2);
-
- if (rc != 0)
- return rc;
-
- rc = erase_range(ef, node, node->size, size);
- if (rc != 0)
- return rc;
-
- exfat_update_mtime(node);
- node->size = size;
- node->flags |= EXFAT_ATTRIB_DIRTY;
- return 0;
-}
-
-uint32_t exfat_count_free_clusters(const struct exfat* ef)
-{
- uint32_t free_clusters = 0;
- uint32_t i;
-
- for (i = 0; i < ef->cmap.size; i++)
- if (BMAP_GET(ef->cmap.chunk, i) == 0)
- free_clusters++;
- return free_clusters;
-}
-
-static int find_used_clusters(const struct exfat* ef,
- cluster_t* a, cluster_t* b)
-{
- const cluster_t end = le32_to_cpu(ef->sb->cluster_count);
-
- /* find first used cluster */
- for (*a = *b + 1; *a < end; (*a)++)
- if (BMAP_GET(ef->cmap.chunk, *a - EXFAT_FIRST_DATA_CLUSTER))
- break;
- if (*a >= end)
- return 1;
-
- /* find last contiguous used cluster */
- for (*b = *a; *b < end; (*b)++)
- if (BMAP_GET(ef->cmap.chunk, *b - EXFAT_FIRST_DATA_CLUSTER) == 0)
- {
- (*b)--;
- break;
- }
-
- return 0;
-}
-
-int exfat_find_used_sectors(const struct exfat* ef, off64_t* a, off64_t* b)
-{
- cluster_t ca, cb;
-
- if (*a == 0 && *b == 0)
- ca = cb = EXFAT_FIRST_DATA_CLUSTER - 1;
- else
- {
- ca = s2c(ef, *a);
- cb = s2c(ef, *b);
- }
- if (find_used_clusters(ef, &ca, &cb) != 0)
- return 1;
- if (*a != 0 || *b != 0)
- *a = c2s(ef, ca);
- *b = c2s(ef, cb) + (CLUSTER_SIZE(*ef->sb) - 1) / SECTOR_SIZE(*ef->sb);
- return 0;
-}