void exfat_put_node(struct exfat* ef, struct exfat_node* node)
{
if (--node->references < 0)
{
char buffer[UTF8_BYTES(EXFAT_NAME_MAX) + 1];
exfat_get_name(node, buffer, sizeof(buffer) - 1);
exfat_bug("reference counter of `%s' is below zero", buffer);
}
if (node->references == 0)
{
/* FIXME handle I/O error */
if (exfat_flush_node(ef, node) != 0)
exfat_bug("node flush failed");
if (node->flags & EXFAT_ATTRIB_UNLINKED)
{
/* free all clusters and node structure itself */
exfat_truncate(ef, node, 0, true);
free(node);
}
/* FIXME handle I/O error */
if (exfat_flush(ef) != 0)
exfat_bug("flush failed");
}
}
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 void dirck(struct exfat* ef, const char* path)
{
struct exfat_node* parent;
struct exfat_node* node;
struct exfat_iterator it;
int rc;
size_t path_length;
char* entry_path;
if (exfat_lookup(ef, &parent, path) != 0)
exfat_bug("directory '%s' is not found", path);
if (!(parent->flags & EXFAT_ATTRIB_DIR))
exfat_bug("'%s' is not a directory (0x%x)", path, parent->flags);
if (nodeck(ef, parent) != 0)
{
exfat_put_node(ef, parent);
return;
}
path_length = strlen(path);
entry_path = malloc(path_length + 1 + UTF8_BYTES(EXFAT_NAME_MAX) + 1);
if (entry_path == NULL)
{
exfat_put_node(ef, parent);
exfat_error("out of memory");
return;
}
strcpy(entry_path, path);
strcat(entry_path, "/");
rc = exfat_opendir(ef, parent, &it);
if (rc != 0)
{
free(entry_path);
exfat_put_node(ef, parent);
return;
}
while ((node = exfat_readdir(ef, &it)))
{
exfat_get_name(node, entry_path + path_length + 1,
UTF8_BYTES(EXFAT_NAME_MAX));
exfat_debug("%s: %s, %"PRIu64" bytes, cluster %u", entry_path,
IS_CONTIGUOUS(*node) ? "contiguous" : "fragmented",
node->size, node->start_cluster);
if (node->flags & EXFAT_ATTRIB_DIR)
{
directories_count++;
dirck(ef, entry_path);
}
else
{
files_count++;
nodeck(ef, node);
}
exfat_put_node(ef, node);
}
exfat_closedir(ef, &it);
exfat_put_node(ef, parent);
free(entry_path);
}
static int shrink_directory(struct exfat* ef, struct exfat_node* dir,
off64_t deleted_offset)
{
const struct exfat_node* node;
const struct exfat_node* last_node;
uint64_t entries = 1; /* a directory always has at leat 1 entry (EOD) */
uint64_t new_size;
struct exfat_entry eod;
off64_t eod_offset;
int rc;
if (!(dir->flags & EXFAT_ATTRIB_DIR))
exfat_bug("attempted to shrink a file");
if (!(dir->flags & EXFAT_ATTRIB_CACHED))
exfat_bug("attempted to shrink uncached directory");
for (last_node = node = dir->child; node; node = node->next)
{
if (deleted_offset < node->entry_offset)
{
/* there are other entries after the removed one, no way to shrink
this directory */
return 0;
}
if (last_node->entry_offset < node->entry_offset)
last_node = node;
}
if (last_node)
{
/* offset of the last entry */
entries += last_node->entry_offset / sizeof(struct exfat_entry);
/* two subentries with meta info */
entries += 2;
/* subentries with file name */
entries += DIV_ROUND_UP(utf16_length(last_node->name),
EXFAT_ENAME_MAX);
}
new_size = DIV_ROUND_UP(entries * sizeof(struct exfat_entry),
CLUSTER_SIZE(*ef->sb)) * CLUSTER_SIZE(*ef->sb);
if (new_size == dir->size)
return 0;
rc = exfat_truncate(ef, dir, new_size);
if (rc != 0)
return rc;
/* put EOD entry at the end of the last cluster */
memset(&eod, 0, sizeof(eod));
eod_offset = new_size - sizeof(struct exfat_entry);
if (last_node)
exfat_write_raw(&eod, sizeof(eod),
co2o(ef, last_node->entry_cluster, eod_offset), ef->fd);
else
exfat_write_raw(&eod, sizeof(eod),
co2o(ef, dir->start_cluster, eod_offset), ef->fd);
return 0;
}
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 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);
if (!set_next_cluster(ef, IS_CONTIGUOUS(*node), last,
EXFAT_CLUSTER_END))
return -EIO;
}
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);
if (!set_next_cluster(ef, IS_CONTIGUOUS(*node), previous,
EXFAT_CLUSTER_FREE))
return -EIO;
free_cluster(ef, previous);
previous = next;
}
return 0;
}
static int shrink_directory(struct exfat* ef, struct exfat_node* dir,
off64_t deleted_offset)
{
const struct exfat_node* node;
const struct exfat_node* last_node;
uint64_t entries = 0;
uint64_t new_size;
int rc;
if (!(dir->flags & EXFAT_ATTRIB_DIR))
exfat_bug("attempted to shrink a file");
if (!(dir->flags & EXFAT_ATTRIB_CACHED))
exfat_bug("attempted to shrink uncached directory");
for (last_node = node = dir->child; node; node = node->next)
{
if (deleted_offset < node->entry_offset)
{
/* there are other entries after the removed one, no way to shrink
this directory */
return 0;
}
if (last_node->entry_offset < node->entry_offset)
last_node = node;
}
if (last_node)
{
/* offset of the last entry */
entries += last_node->entry_offset / sizeof(struct exfat_entry);
/* two subentries with meta info */
entries += 2;
/* subentries with file name */
entries += DIV_ROUND_UP(utf16_length(last_node->name),
EXFAT_ENAME_MAX);
}
new_size = DIV_ROUND_UP(entries * sizeof(struct exfat_entry),
CLUSTER_SIZE(*ef->sb)) * CLUSTER_SIZE(*ef->sb);
if (new_size == 0) /* directory always has at least 1 cluster */
new_size = CLUSTER_SIZE(*ef->sb);
if (new_size == dir->size)
return 0;
rc = exfat_truncate(ef, dir, new_size, true);
if (rc != 0)
return rc;
return 0;
}
static void reset_cache(struct exfat* ef, struct exfat_node* node)
{
char buffer[UTF8_BYTES(EXFAT_NAME_MAX) + 1];
while (node->child)
{
struct exfat_node* p = node->child;
reset_cache(ef, p);
tree_detach(p);
free(p);
}
node->flags &= ~EXFAT_ATTRIB_CACHED;
if (node->references != 0)
{
exfat_get_name(node, buffer, sizeof(buffer) - 1);
exfat_warn("non-zero reference counter (%d) for '%s'",
node->references, buffer);
}
if (node != ef->root && (node->flags & EXFAT_ATTRIB_DIRTY))
{
exfat_get_name(node, buffer, sizeof(buffer) - 1);
exfat_bug("node '%s' is dirty", buffer);
}
while (node->references)
exfat_put_node(ef, node);
}
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;
}
/*
* Cluster to sector.
*/
static off_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) +
((off_t) (cluster - EXFAT_FIRST_DATA_CLUSTER) << ef->sb->spc_bits);
}
void exfat_flush_node(struct exfat* ef, struct exfat_node* node)
{
cluster_t cluster;
off64_t offset;
off64_t meta1_offset, meta2_offset;
struct exfat_entry_meta1 meta1;
struct exfat_entry_meta2 meta2;
if (ef->ro)
exfat_bug("unable to flush node to read-only FS");
if (node->parent == NULL)
return; /* do not flush unlinked node */
cluster = node->entry_cluster;
offset = node->entry_offset;
meta1_offset = co2o(ef, cluster, offset);
next_entry(ef, node->parent, &cluster, &offset);
meta2_offset = co2o(ef, cluster, offset);
exfat_read_raw(&meta1, sizeof(meta1), meta1_offset, ef->fd);
if (meta1.type != EXFAT_ENTRY_FILE)
exfat_bug("invalid type of meta1: 0x%hhx", meta1.type);
meta1.attrib = cpu_to_le16(node->flags);
exfat_unix2exfat(node->mtime, &meta1.mdate, &meta1.mtime, &meta1.mtime_cs);
exfat_unix2exfat(node->atime, &meta1.adate, &meta1.atime, NULL);
exfat_read_raw(&meta2, sizeof(meta2), meta2_offset, ef->fd);
if (meta2.type != EXFAT_ENTRY_FILE_INFO)
exfat_bug("invalid type of meta2: 0x%hhx", meta2.type);
meta2.size = meta2.real_size = cpu_to_le64(node->size);
meta2.start_cluster = cpu_to_le32(node->start_cluster);
meta2.flags = EXFAT_FLAG_ALWAYS1;
/* empty files must not be marked as contiguous */
if (node->size != 0 && IS_CONTIGUOUS(*node))
meta2.flags |= EXFAT_FLAG_CONTIGUOUS;
/* name hash remains unchanged, no need to recalculate it */
meta1.checksum = exfat_calc_checksum(&meta1, &meta2, node->name);
exfat_write_raw(&meta1, sizeof(meta1), meta1_offset, ef->fd);
exfat_write_raw(&meta2, sizeof(meta2), meta2_offset, ef->fd);
node->flags &= ~EXFAT_ATTRIB_DIRTY;
}
cluster_t exfat_next_cluster(const struct exfat* ef,
const struct exfat_node* node, cluster_t cluster)
{
le32_t next;
loff_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);
/* FIXME handle I/O error */
if (exfat_pread(ef->dev, &next, sizeof(next), fat_offset) < 0)
exfat_bug("failed to read the next cluster after %#x", cluster);
return le32_to_cpu(next);
}
void exfat_pwrite(struct exfat_dev* dev, const void* buffer, size_t size,
off_t offset)
{
#ifdef USE_UBLIO
if (ublio_pwrite(dev->ufh, buffer, size, offset) != size)
#else
if (pwrite(dev->fd, buffer, size, offset) != size)
#endif
exfat_bug("failed to write %zu bytes to file at %"PRIu64, size,
(uint64_t) offset);
}
void exfat_pread(struct exfat_dev* dev, void* buffer, size_t size,
off_t offset)
{
#ifdef USE_UBLIO
if (ublio_pread(dev->ufh, buffer, size, offset) != size)
#else
if (pread(dev->fd, buffer, size, offset) != size)
#endif
exfat_bug("failed to read %zu bytes from file at %"PRIu64, size,
(uint64_t) offset);
}
off64_t get_position(const struct fs_object* object)
{
const struct fs_object** pp;
off64_t position = 0;
for (pp = objects; *pp; pp++)
{
position = ROUND_UP(position, (*pp)->get_alignment());
if (*pp == object)
return position;
position += (*pp)->get_size();
}
exfat_bug("unknown object");
}
cluster_t exfat_next_cluster(const struct exfat* ef,
const struct exfat_node* node, cluster_t cluster)
{
le32_t next;
off_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);
}
/**
* This function must be called on rmdir and unlink (after the last
* exfat_put_node()) to free clusters.
*/
int exfat_cleanup_node(struct exfat* ef, struct exfat_node* node)
{
int rc = 0;
if (node->references != 0)
exfat_bug("unable to cleanup a node with %d references",
node->references);
if (node->flags & EXFAT_ATTRIB_UNLINKED)
{
/* free all clusters and node structure itself */
rc = exfat_truncate(ef, node, 0, true);
/* free the node even in case of error or its memory will be lost */
free(node);
}
return rc;
}
static int opendir(struct exfat* ef, const struct exfat_node* dir,
struct iterator* it)
{
if (!(dir->flags & EXFAT_ATTRIB_DIR))
exfat_bug("not a directory");
it->cluster = dir->start_cluster;
it->offset = 0;
it->contiguous = IS_CONTIGUOUS(*dir);
it->chunk = malloc(CLUSTER_SIZE(*ef->sb));
if (it->chunk == NULL)
{
exfat_error("out of memory");
return -ENOMEM;
}
exfat_read_raw(it->chunk, CLUSTER_SIZE(*ef->sb),
exfat_c2o(ef, it->cluster), ef->fd);
return 0;
}
void exfat_put_node(struct exfat* ef, struct exfat_node* node)
{
char buffer[UTF8_BYTES(EXFAT_NAME_MAX) + 1];
--node->references;
if (node->references < 0)
{
exfat_get_name(node, buffer, sizeof(buffer) - 1);
exfat_bug("reference counter of '%s' is below zero", buffer);
}
else if (node->references == 0 && node != ef->root)
{
if (node->flags & EXFAT_ATTRIB_DIRTY)
{
exfat_get_name(node, buffer, sizeof(buffer) - 1);
exfat_warn("dirty node '%s' with zero references", buffer);
}
}
}
void exfat_put_node(struct exfat* ef, struct exfat_node* node)
{
if (--node->references < 0)
{
char buffer[EXFAT_NAME_MAX + 1];
exfat_get_name(node, buffer, EXFAT_NAME_MAX);
exfat_bug("reference counter of `%s' is below zero", buffer);
}
if (node->references == 0)
{
if (node->flags & EXFAT_ATTRIB_DIRTY)
exfat_flush_node(ef, node);
if (node->flags & EXFAT_ATTRIB_UNLINKED)
{
/* free all clusters and node structure itself */
exfat_truncate(ef, node, 0);
free(node);
}
if (ef->cmap.dirty)
exfat_flush_cmap(ef);
}
}
void exfat_read_raw(void* buffer, size_t size, off_t offset, int fd)
{
if (pread(fd, buffer, size, offset) != size)
exfat_bug("failed to read %zu bytes from file at %"PRIu64, size,
(uint64_t) offset);
}
void exfat_write_raw(const void* buffer, size_t size, off_t offset, int fd)
{
if (pwrite(fd, buffer, size, offset) != size)
exfat_bug("failed to write %zu bytes to file at %"PRIu64, size,
(uint64_t) offset);
}