blob: 1d663870c9bb84301df752f9ad407bf6d4d9c821 [file] [log] [blame]
/*
node.c (09.10.09)
exFAT file system implementation library.
Free exFAT implementation.
Copyright (C) 2010-2014 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 2 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, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "exfat.h"
#include <errno.h>
#include <string.h>
#include <inttypes.h>
/* on-disk nodes iterator */
struct iterator
{
cluster_t cluster;
off64_t offset;
int contiguous;
char* chunk;
};
struct exfat_node* exfat_get_node(struct exfat_node* node)
{
/* if we switch to multi-threaded mode we will need atomic
increment here and atomic decrement in exfat_put_node() */
node->references++;
return node;
}
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);
}
}
}
/**
* 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;
}
/**
* Cluster + offset from the beginning of the directory to absolute offset.
*/
static off64_t co2o(struct exfat* ef, cluster_t cluster, off64_t offset)
{
return exfat_c2o(ef, cluster) + offset % CLUSTER_SIZE(*ef->sb);
}
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;
}
if (exfat_pread(ef->dev, it->chunk, CLUSTER_SIZE(*ef->sb),
exfat_c2o(ef, it->cluster)) < 0)
{
exfat_error("failed to read directory cluster %#x", it->cluster);
return -EIO;
}
return 0;
}
static void closedir(struct iterator* it)
{
it->cluster = 0;
it->offset = 0;
it->contiguous = 0;
free(it->chunk);
it->chunk = NULL;
}
static bool fetch_next_entry(struct exfat* ef, const struct exfat_node* parent,
struct iterator* it)
{
/* move iterator to the next entry in the directory */
it->offset += sizeof(struct exfat_entry);
/* fetch the next cluster if needed */
if ((it->offset & (CLUSTER_SIZE(*ef->sb) - 1)) == 0)
{
/* reached the end of directory; the caller should check this
condition too */
if (it->offset >= parent->size)
return true;
it->cluster = exfat_next_cluster(ef, parent, it->cluster);
if (CLUSTER_INVALID(it->cluster))
{
exfat_error("invalid cluster 0x%x while reading directory",
it->cluster);
return false;
}
if (exfat_pread(ef->dev, it->chunk, CLUSTER_SIZE(*ef->sb),
exfat_c2o(ef, it->cluster)) < 0)
{
exfat_error("failed to read the next directory cluster %#x",
it->cluster);
return false;
}
}
return true;
}
static struct exfat_node* allocate_node(void)
{
struct exfat_node* node = malloc(sizeof(struct exfat_node));
if (node == NULL)
{
exfat_error("failed to allocate node");
return NULL;
}
memset(node, 0, sizeof(struct exfat_node));
return node;
}
static void init_node_meta1(struct exfat_node* node,
const struct exfat_entry_meta1* meta1)
{
node->flags = le16_to_cpu(meta1->attrib);
node->mtime = exfat_exfat2unix(meta1->mdate, meta1->mtime,
meta1->mtime_cs);
/* there is no centiseconds field for atime */
node->atime = exfat_exfat2unix(meta1->adate, meta1->atime, 0);
}
static void init_node_meta2(struct exfat_node* node,
const struct exfat_entry_meta2* meta2)
{
node->size = le64_to_cpu(meta2->size);
node->start_cluster = le32_to_cpu(meta2->start_cluster);
node->fptr_cluster = node->start_cluster;
if (meta2->flags & EXFAT_FLAG_CONTIGUOUS)
node->flags |= EXFAT_ATTRIB_CONTIGUOUS;
}
static const struct exfat_entry* get_entry_ptr(const struct exfat* ef,
const struct iterator* it)
{
return (const struct exfat_entry*)
(it->chunk + it->offset % CLUSTER_SIZE(*ef->sb));
}
static bool check_node(const struct exfat_node* node, uint16_t actual_checksum,
uint16_t reference_checksum, uint64_t valid_size)
{
char buffer[UTF8_BYTES(EXFAT_NAME_MAX) + 1];
/*
Validate checksum first. If it's invalid all other fields probably
contain just garbage.
*/
if (actual_checksum != reference_checksum)
{
exfat_get_name(node, buffer, sizeof(buffer) - 1);
exfat_error("'%s' has invalid checksum (%#hx != %#hx)", buffer,
actual_checksum, reference_checksum);
return false;
}
/*
exFAT does not support sparse files but allows files with uninitialized
clusters. For such files valid_size means initialized data size and
cannot be greater than file size. See SetFileValidData() function
description in MSDN.
*/
if (valid_size > node->size)
{
exfat_get_name(node, buffer, sizeof(buffer) - 1);
exfat_error("'%s' has valid size (%"PRIu64") greater than size "
"(%"PRIu64")", buffer, valid_size, node->size);
return false;
}
return true;
}
/*
* Reads one entry in directory at position pointed by iterator and fills
* node structure.
*/
static int readdir(struct exfat* ef, const struct exfat_node* parent,
struct exfat_node** node, struct iterator* it)
{
int rc = -EIO;
const struct exfat_entry* entry;
const struct exfat_entry_meta1* meta1;
const struct exfat_entry_meta2* meta2;
const struct exfat_entry_name* file_name;
const struct exfat_entry_upcase* upcase;
const struct exfat_entry_bitmap* bitmap;
const struct exfat_entry_label* label;
uint8_t continuations = 0;
le16_t* namep = NULL;
uint16_t reference_checksum = 0;
uint16_t actual_checksum = 0;
uint64_t valid_size = 0;
*node = NULL;
for (;;)
{
if (it->offset >= parent->size)
{
if (continuations != 0)
{
exfat_error("expected %hhu continuations", continuations);
goto error;
}
return -ENOENT; /* that's OK, means end of directory */
}
entry = get_entry_ptr(ef, it);
switch (entry->type)
{
case EXFAT_ENTRY_FILE:
if (continuations != 0)
{
exfat_error("expected %hhu continuations before new entry",
continuations);
goto error;
}
meta1 = (const struct exfat_entry_meta1*) entry;
continuations = meta1->continuations;
/* each file entry must have at least 2 continuations:
info and name */
if (continuations < 2)
{
exfat_error("too few continuations (%hhu)", continuations);
goto error;
}
if (continuations > 1 +
DIV_ROUND_UP(EXFAT_NAME_MAX, EXFAT_ENAME_MAX))
{
exfat_error("too many continuations (%hhu)", continuations);
goto error;
}
reference_checksum = le16_to_cpu(meta1->checksum);
actual_checksum = exfat_start_checksum(meta1);
*node = allocate_node();
if (*node == NULL)
{
rc = -ENOMEM;
goto error;
}
/* new node has zero reference counter */
(*node)->entry_cluster = it->cluster;
(*node)->entry_offset = it->offset;
init_node_meta1(*node, meta1);
namep = (*node)->name;
break;
case EXFAT_ENTRY_FILE_INFO:
if (continuations < 2)
{
exfat_error("unexpected continuation (%hhu)",
continuations);
goto error;
}
meta2 = (const struct exfat_entry_meta2*) entry;
if (meta2->flags & ~(EXFAT_FLAG_ALWAYS1 | EXFAT_FLAG_CONTIGUOUS))
{
exfat_error("unknown flags in meta2 (0x%hhx)", meta2->flags);
goto error;
}
init_node_meta2(*node, meta2);
actual_checksum = exfat_add_checksum(entry, actual_checksum);
valid_size = le64_to_cpu(meta2->valid_size);
/* empty files must be marked as non-contiguous */
if ((*node)->size == 0 && (meta2->flags & EXFAT_FLAG_CONTIGUOUS))
{
exfat_error("empty file marked as contiguous (0x%hhx)",
meta2->flags);
goto error;
}
/* directories must be aligned on at cluster boundary */
if (((*node)->flags & EXFAT_ATTRIB_DIR) &&
(*node)->size % CLUSTER_SIZE(*ef->sb) != 0)
{
exfat_error("directory has invalid size %"PRIu64" bytes",
(*node)->size);
goto error;
}
--continuations;
break;
case EXFAT_ENTRY_FILE_NAME:
if (continuations == 0)
{
exfat_error("unexpected continuation");
goto error;
}
file_name = (const struct exfat_entry_name*) entry;
actual_checksum = exfat_add_checksum(entry, actual_checksum);
memcpy(namep, file_name->name,
MIN(EXFAT_ENAME_MAX,
((*node)->name + EXFAT_NAME_MAX - namep)) *
sizeof(le16_t));
namep += EXFAT_ENAME_MAX;
if (--continuations == 0)
{
if (!check_node(*node, actual_checksum, reference_checksum,
valid_size))
goto error;
if (!fetch_next_entry(ef, parent, it))
goto error;
return 0; /* entry completed */
}
break;
case EXFAT_ENTRY_UPCASE:
if (ef->upcase != NULL)
break;
upcase = (const struct exfat_entry_upcase*) entry;
if (CLUSTER_INVALID(le32_to_cpu(upcase->start_cluster)))
{
exfat_error("invalid cluster 0x%x in upcase table",
le32_to_cpu(upcase->start_cluster));
goto error;
}
if (le64_to_cpu(upcase->size) == 0 ||
le64_to_cpu(upcase->size) > 0xffff * sizeof(uint16_t) ||
le64_to_cpu(upcase->size) % sizeof(uint16_t) != 0)
{
exfat_error("bad upcase table size (%"PRIu64" bytes)",
le64_to_cpu(upcase->size));
goto error;
}
ef->upcase = malloc(le64_to_cpu(upcase->size));
if (ef->upcase == NULL)
{
exfat_error("failed to allocate upcase table (%"PRIu64" bytes)",
le64_to_cpu(upcase->size));
rc = -ENOMEM;
goto error;
}
ef->upcase_chars = le64_to_cpu(upcase->size) / sizeof(le16_t);
if (exfat_pread(ef->dev, ef->upcase, le64_to_cpu(upcase->size),
exfat_c2o(ef, le32_to_cpu(upcase->start_cluster))) < 0)
{
exfat_error("failed to read upper case table "
"(%"PRIu64" bytes starting at cluster %#x)",
le64_to_cpu(upcase->size),
le32_to_cpu(upcase->start_cluster));
goto error;
}
break;
case EXFAT_ENTRY_BITMAP:
bitmap = (const struct exfat_entry_bitmap*) entry;
ef->cmap.start_cluster = le32_to_cpu(bitmap->start_cluster);
if (CLUSTER_INVALID(ef->cmap.start_cluster))
{
exfat_error("invalid cluster 0x%x in clusters bitmap",
ef->cmap.start_cluster);
goto error;
}
ef->cmap.size = le32_to_cpu(ef->sb->cluster_count) -
EXFAT_FIRST_DATA_CLUSTER;
if (le64_to_cpu(bitmap->size) < DIV_ROUND_UP(ef->cmap.size, 8))
{
exfat_error("invalid clusters bitmap size: %"PRIu64
" (expected at least %u)",
le64_to_cpu(bitmap->size),
DIV_ROUND_UP(ef->cmap.size, 8));
goto error;
}
/* FIXME bitmap can be rather big, up to 512 MB */
ef->cmap.chunk_size = ef->cmap.size;
ef->cmap.chunk = malloc(BMAP_SIZE(ef->cmap.chunk_size));
if (ef->cmap.chunk == NULL)
{
exfat_error("failed to allocate clusters bitmap chunk "
"(%"PRIu64" bytes)", le64_to_cpu(bitmap->size));
rc = -ENOMEM;
goto error;
}
if (exfat_pread(ef->dev, ef->cmap.chunk,
BMAP_SIZE(ef->cmap.chunk_size),
exfat_c2o(ef, ef->cmap.start_cluster)) < 0)
{
exfat_error("failed to read clusters bitmap "
"(%"PRIu64" bytes starting at cluster %#x)",
le64_to_cpu(bitmap->size), ef->cmap.start_cluster);
goto error;
}
break;
case EXFAT_ENTRY_LABEL:
label = (const struct exfat_entry_label*) entry;
if (label->length > EXFAT_ENAME_MAX)
{
exfat_error("too long label (%hhu chars)", label->length);
goto error;
}
if (utf16_to_utf8(ef->label, label->name,
sizeof(ef->label) - 1, EXFAT_ENAME_MAX) != 0)
goto error;
break;
default:
if (entry->type & EXFAT_ENTRY_VALID)
{
exfat_error("unknown entry type 0x%hhx", entry->type);
goto error;
}
break;
}
if (!fetch_next_entry(ef, parent, it))
goto error;
}
/* we never reach here */
error:
free(*node);
*node = NULL;
return rc;
}
int exfat_cache_directory(struct exfat* ef, struct exfat_node* dir)
{
struct iterator it;
int rc;
struct exfat_node* node;
struct exfat_node* current = NULL;
if (dir->flags & EXFAT_ATTRIB_CACHED)
return 0; /* already cached */
rc = opendir(ef, dir, &it);
if (rc != 0)
return rc;
while ((rc = readdir(ef, dir, &node, &it)) == 0)
{
node->parent = dir;
if (current != NULL)
{
current->next = node;
node->prev = current;
}
else
dir->child = node;
current = node;
}
closedir(&it);
if (rc != -ENOENT)
{
/* rollback */
for (current = dir->child; current; current = node)
{
node = current->next;
free(current);
}
dir->child = NULL;
return rc;
}
dir->flags |= EXFAT_ATTRIB_CACHED;
return 0;
}
static void tree_attach(struct exfat_node* dir, struct exfat_node* node)
{
node->parent = dir;
if (dir->child)
{
dir->child->prev = node;
node->next = dir->child;
}
dir->child = node;
}
static void tree_detach(struct exfat_node* node)
{
if (node->prev)
node->prev->next = node->next;
else /* this is the first node in the list */
node->parent->child = node->next;
if (node->next)
node->next->prev = node->prev;
node->parent = NULL;
node->prev = NULL;
node->next = NULL;
}
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);
}
void exfat_reset_cache(struct exfat* ef)
{
reset_cache(ef, ef->root);
}
static bool next_entry(struct exfat* ef, const struct exfat_node* parent,
cluster_t* cluster, off64_t* offset)
{
*offset += sizeof(struct exfat_entry);
if (*offset % CLUSTER_SIZE(*ef->sb) == 0)
{
*cluster = exfat_next_cluster(ef, parent, *cluster);
if (CLUSTER_INVALID(*cluster))
{
exfat_error("invalid cluster %#x while getting next entry",
*cluster);
return false;
}
}
return true;
}
int 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 (!(node->flags & EXFAT_ATTRIB_DIRTY))
return 0; /* no need to flush */
if (ef->ro)
exfat_bug("unable to flush node to read-only FS");
if (node->parent == NULL)
return 0; /* do not flush unlinked node */
cluster = node->entry_cluster;
offset = node->entry_offset;
meta1_offset = co2o(ef, cluster, offset);
if (!next_entry(ef, node->parent, &cluster, &offset))
return -EIO;
meta2_offset = co2o(ef, cluster, offset);
if (exfat_pread(ef->dev, &meta1, sizeof(meta1), meta1_offset) < 0)
{
exfat_error("failed to read meta1 entry on flush");
return -EIO;
}
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);
if (exfat_pread(ef->dev, &meta2, sizeof(meta2), meta2_offset) < 0)
{
exfat_error("failed to read meta2 entry on flush");
return -EIO;
}
if (meta2.type != EXFAT_ENTRY_FILE_INFO)
exfat_bug("invalid type of meta2: 0x%hhx", meta2.type);
meta2.size = meta2.valid_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);
if (exfat_pwrite(ef->dev, &meta1, sizeof(meta1), meta1_offset) < 0)
{
exfat_error("failed to write meta1 entry on flush");
return -EIO;
}
if (exfat_pwrite(ef->dev, &meta2, sizeof(meta2), meta2_offset) < 0)
{
exfat_error("failed to write meta2 entry on flush");
return -EIO;
}
node->flags &= ~EXFAT_ATTRIB_DIRTY;
return 0;
}
static bool erase_entry(struct exfat* ef, struct exfat_node* node)
{
cluster_t cluster = node->entry_cluster;
off64_t offset = node->entry_offset;
int name_entries = DIV_ROUND_UP(utf16_length(node->name), EXFAT_ENAME_MAX);
uint8_t entry_type;
entry_type = EXFAT_ENTRY_FILE & ~EXFAT_ENTRY_VALID;
if (exfat_pwrite(ef->dev, &entry_type, 1, co2o(ef, cluster, offset)) < 0)
{
exfat_error("failed to erase meta1 entry");
return false;
}
if (!next_entry(ef, node->parent, &cluster, &offset))
return false;
entry_type = EXFAT_ENTRY_FILE_INFO & ~EXFAT_ENTRY_VALID;
if (exfat_pwrite(ef->dev, &entry_type, 1, co2o(ef, cluster, offset)) < 0)
{
exfat_error("failed to erase meta2 entry");
return false;
}
while (name_entries--)
{
if (!next_entry(ef, node->parent, &cluster, &offset))
return false;
entry_type = EXFAT_ENTRY_FILE_NAME & ~EXFAT_ENTRY_VALID;
if (exfat_pwrite(ef->dev, &entry_type, 1,
co2o(ef, cluster, offset)) < 0)
{
exfat_error("failed to erase name entry");
return false;
}
}
return true;
}
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;
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;
return exfat_truncate(ef, dir, new_size, true);
}
static int delete(struct exfat* ef, struct exfat_node* node)
{
struct exfat_node* parent = node->parent;
off64_t deleted_offset = node->entry_offset;
int rc;
exfat_get_node(parent);
if (!erase_entry(ef, node))
{
exfat_put_node(ef, parent);
return -EIO;
}
exfat_update_mtime(parent);
tree_detach(node);
rc = shrink_directory(ef, parent, deleted_offset);
node->flags |= EXFAT_ATTRIB_UNLINKED;
if (rc != 0)
{
exfat_flush_node(ef, parent);
exfat_put_node(ef, parent);
return rc;
}
rc = exfat_flush_node(ef, parent);
exfat_put_node(ef, parent);
return rc;
}
int exfat_unlink(struct exfat* ef, struct exfat_node* node)
{
if (node->flags & EXFAT_ATTRIB_DIR)
return -EISDIR;
return delete(ef, node);
}
int exfat_rmdir(struct exfat* ef, struct exfat_node* node)
{
int rc;
if (!(node->flags & EXFAT_ATTRIB_DIR))
return -ENOTDIR;
/* check that directory is empty */
rc = exfat_cache_directory(ef, node);
if (rc != 0)
return rc;
if (node->child)
return -ENOTEMPTY;
return delete(ef, node);
}
static int grow_directory(struct exfat* ef, struct exfat_node* dir,
uint64_t asize, uint32_t difference)
{
return exfat_truncate(ef, dir,
DIV_ROUND_UP(asize + difference, CLUSTER_SIZE(*ef->sb))
* CLUSTER_SIZE(*ef->sb), true);
}
static int find_slot(struct exfat* ef, struct exfat_node* dir,
cluster_t* cluster, off64_t* offset, int subentries)
{
struct iterator it;
int rc;
const struct exfat_entry* entry;
int contiguous = 0;
rc = opendir(ef, dir, &it);
if (rc != 0)
return rc;
for (;;)
{
if (contiguous == 0)
{
*cluster = it.cluster;
*offset = it.offset;
}
entry = get_entry_ptr(ef, &it);
if (entry->type & EXFAT_ENTRY_VALID)
contiguous = 0;
else
contiguous++;
if (contiguous == subentries)
break; /* suitable slot is found */
if (it.offset + sizeof(struct exfat_entry) >= dir->size)
{
rc = grow_directory(ef, dir, dir->size,
(subentries - contiguous) * sizeof(struct exfat_entry));
if (rc != 0)
{
closedir(&it);
return rc;
}
}
if (!fetch_next_entry(ef, dir, &it))
{
closedir(&it);
return -EIO;
}
}
closedir(&it);
return 0;
}
static int write_entry(struct exfat* ef, struct exfat_node* dir,
const le16_t* name, cluster_t cluster, off64_t offset, uint16_t attrib)
{
struct exfat_node* node;
struct exfat_entry_meta1 meta1;
struct exfat_entry_meta2 meta2;
const size_t name_length = utf16_length(name);
const int name_entries = DIV_ROUND_UP(name_length, EXFAT_ENAME_MAX);
int i;
node = allocate_node();
if (node == NULL)
return -ENOMEM;
node->entry_cluster = cluster;
node->entry_offset = offset;
memcpy(node->name, name, name_length * sizeof(le16_t));
memset(&meta1, 0, sizeof(meta1));
meta1.type = EXFAT_ENTRY_FILE;
meta1.continuations = 1 + name_entries;
meta1.attrib = cpu_to_le16(attrib);
exfat_unix2exfat(time(NULL), &meta1.crdate, &meta1.crtime,
&meta1.crtime_cs);
meta1.adate = meta1.mdate = meta1.crdate;
meta1.atime = meta1.mtime = meta1.crtime;
meta1.mtime_cs = meta1.crtime_cs; /* there is no atime_cs */
memset(&meta2, 0, sizeof(meta2));
meta2.type = EXFAT_ENTRY_FILE_INFO;
meta2.flags = EXFAT_FLAG_ALWAYS1;
meta2.name_length = name_length;
meta2.name_hash = exfat_calc_name_hash(ef, node->name);
meta2.start_cluster = cpu_to_le32(EXFAT_CLUSTER_FREE);
meta1.checksum = exfat_calc_checksum(&meta1, &meta2, node->name);
if (exfat_pwrite(ef->dev, &meta1, sizeof(meta1),
co2o(ef, cluster, offset)) < 0)
{
exfat_error("failed to write meta1 entry");
return -EIO;
}
if (!next_entry(ef, dir, &cluster, &offset))
return -EIO;
if (exfat_pwrite(ef->dev, &meta2, sizeof(meta2),
co2o(ef, cluster, offset)) < 0)
{
exfat_error("failed to write meta2 entry");
return -EIO;
}
for (i = 0; i < name_entries; i++)
{
struct exfat_entry_name name_entry = {EXFAT_ENTRY_FILE_NAME, 0};
memcpy(name_entry.name, node->name + i * EXFAT_ENAME_MAX,
MIN(EXFAT_ENAME_MAX, EXFAT_NAME_MAX - i * EXFAT_ENAME_MAX) *
sizeof(le16_t));
if (!next_entry(ef, dir, &cluster, &offset))
return -EIO;
if (exfat_pwrite(ef->dev, &name_entry, sizeof(name_entry),
co2o(ef, cluster, offset)) < 0)
{
exfat_error("failed to write name entry");
return -EIO;
}
}
init_node_meta1(node, &meta1);
init_node_meta2(node, &meta2);
tree_attach(dir, node);
exfat_update_mtime(dir);
return 0;
}
static int create(struct exfat* ef, const char* path, uint16_t attrib)
{
struct exfat_node* dir;
struct exfat_node* existing;
cluster_t cluster = EXFAT_CLUSTER_BAD;
off64_t offset = -1;
le16_t name[EXFAT_NAME_MAX + 1];
int rc;
rc = exfat_split(ef, &dir, &existing, name, path);
if (rc != 0)
return rc;
if (existing != NULL)
{
exfat_put_node(ef, existing);
exfat_put_node(ef, dir);
return -EEXIST;
}
rc = find_slot(ef, dir, &cluster, &offset,
2 + DIV_ROUND_UP(utf16_length(name), EXFAT_ENAME_MAX));
if (rc != 0)
{
exfat_put_node(ef, dir);
return rc;
}
rc = write_entry(ef, dir, name, cluster, offset, attrib);
if (rc != 0)
{
exfat_put_node(ef, dir);
return rc;
}
rc = exfat_flush_node(ef, dir);
exfat_put_node(ef, dir);
return rc;
}
int exfat_mknod(struct exfat* ef, const char* path)
{
return create(ef, path, EXFAT_ATTRIB_ARCH);
}
int exfat_mkdir(struct exfat* ef, const char* path)
{
int rc;
struct exfat_node* node;
rc = create(ef, path, EXFAT_ATTRIB_ARCH | EXFAT_ATTRIB_DIR);
if (rc != 0)
return rc;
rc = exfat_lookup(ef, &node, path);
if (rc != 0)
return 0;
/* directories always have at least one cluster */
rc = exfat_truncate(ef, node, CLUSTER_SIZE(*ef->sb), true);
if (rc != 0)
{
delete(ef, node);
exfat_put_node(ef, node);
return rc;
}
rc = exfat_flush_node(ef, node);
if (rc != 0)
{
delete(ef, node);
exfat_put_node(ef, node);
return rc;
}
exfat_put_node(ef, node);
return 0;
}
static int rename_entry(struct exfat* ef, struct exfat_node* dir,
struct exfat_node* node, const le16_t* name, cluster_t new_cluster,
off64_t new_offset)
{
struct exfat_entry_meta1 meta1;
struct exfat_entry_meta2 meta2;
cluster_t old_cluster = node->entry_cluster;
off64_t old_offset = node->entry_offset;
const size_t name_length = utf16_length(name);
const int name_entries = DIV_ROUND_UP(name_length, EXFAT_ENAME_MAX);
int i;
if (exfat_pread(ef->dev, &meta1, sizeof(meta1),
co2o(ef, old_cluster, old_offset)) < 0)
{
exfat_error("failed to read meta1 entry on rename");
return -EIO;
}
if (!next_entry(ef, node->parent, &old_cluster, &old_offset))
return -EIO;
if (exfat_pread(ef->dev, &meta2, sizeof(meta2),
co2o(ef, old_cluster, old_offset)) < 0)
{
exfat_error("failed to read meta2 entry on rename");
return -EIO;
}
meta1.continuations = 1 + name_entries;
meta2.name_hash = exfat_calc_name_hash(ef, name);
meta2.name_length = name_length;
meta1.checksum = exfat_calc_checksum(&meta1, &meta2, name);
if (!erase_entry(ef, node))
return -EIO;
node->entry_cluster = new_cluster;
node->entry_offset = new_offset;
if (exfat_pwrite(ef->dev, &meta1, sizeof(meta1),
co2o(ef, new_cluster, new_offset)) < 0)
{
exfat_error("failed to write meta1 entry on rename");
return -EIO;
}
if (!next_entry(ef, dir, &new_cluster, &new_offset))
return -EIO;
if (exfat_pwrite(ef->dev, &meta2, sizeof(meta2),
co2o(ef, new_cluster, new_offset)) < 0)
{
exfat_error("failed to write meta2 entry on rename");
return -EIO;
}
for (i = 0; i < name_entries; i++)
{
struct exfat_entry_name name_entry = {EXFAT_ENTRY_FILE_NAME, 0};
memcpy(name_entry.name, name + i * EXFAT_ENAME_MAX,
EXFAT_ENAME_MAX * sizeof(le16_t));
if (!next_entry(ef, dir, &new_cluster, &new_offset))
return -EIO;
if (exfat_pwrite(ef->dev, &name_entry, sizeof(name_entry),
co2o(ef, new_cluster, new_offset)) < 0)
{
exfat_error("failed to write name entry on rename");
return -EIO;
}
}
memcpy(node->name, name, (EXFAT_NAME_MAX + 1) * sizeof(le16_t));
tree_detach(node);
tree_attach(dir, node);
return 0;
}
int exfat_rename(struct exfat* ef, const char* old_path, const char* new_path)
{
struct exfat_node* node;
struct exfat_node* existing;
struct exfat_node* dir;
cluster_t cluster = EXFAT_CLUSTER_BAD;
off64_t offset = -1;
le16_t name[EXFAT_NAME_MAX + 1];
int rc;
rc = exfat_lookup(ef, &node, old_path);
if (rc != 0)
return rc;
rc = exfat_split(ef, &dir, &existing, name, new_path);
if (rc != 0)
{
exfat_put_node(ef, node);
return rc;
}
/* check that target is not a subdirectory of the source */
if (node->flags & EXFAT_ATTRIB_DIR)
{
struct exfat_node* p;
for (p = dir; p; p = p->parent)
if (node == p)
{
if (existing != NULL)
exfat_put_node(ef, existing);
exfat_put_node(ef, dir);
exfat_put_node(ef, node);
return -EINVAL;
}
}
if (existing != NULL)
{
/* remove target if it's not the same node as source */
if (existing != node)
{
if (existing->flags & EXFAT_ATTRIB_DIR)
{
if (node->flags & EXFAT_ATTRIB_DIR)
rc = exfat_rmdir(ef, existing);
else
rc = -ENOTDIR;
}
else
{
if (!(node->flags & EXFAT_ATTRIB_DIR))
rc = exfat_unlink(ef, existing);
else
rc = -EISDIR;
}
exfat_put_node(ef, existing);
if (rc != 0)
{
exfat_put_node(ef, dir);
exfat_put_node(ef, node);
return rc;
}
}
else
exfat_put_node(ef, existing);
}
rc = find_slot(ef, dir, &cluster, &offset,
2 + DIV_ROUND_UP(utf16_length(name), EXFAT_ENAME_MAX));
if (rc != 0)
{
exfat_put_node(ef, dir);
exfat_put_node(ef, node);
return rc;
}
rc = rename_entry(ef, dir, node, name, cluster, offset);
exfat_put_node(ef, dir);
exfat_put_node(ef, node);
return rc;
}
void exfat_utimes(struct exfat_node* node, const struct timespec tv[2])
{
node->atime = tv[0].tv_sec;
node->mtime = tv[1].tv_sec;
node->flags |= EXFAT_ATTRIB_DIRTY;
}
void exfat_update_atime(struct exfat_node* node)
{
node->atime = time(NULL);
node->flags |= EXFAT_ATTRIB_DIRTY;
}
void exfat_update_mtime(struct exfat_node* node)
{
node->mtime = time(NULL);
node->flags |= EXFAT_ATTRIB_DIRTY;
}
const char* exfat_get_label(struct exfat* ef)
{
return ef->label;
}
static int find_label(struct exfat* ef, cluster_t* cluster, off64_t* offset)
{
struct iterator it;
int rc;
rc = opendir(ef, ef->root, &it);
if (rc != 0)
return rc;
for (;;)
{
if (it.offset >= ef->root->size)
{
closedir(&it);
return -ENOENT;
}
if (get_entry_ptr(ef, &it)->type == EXFAT_ENTRY_LABEL)
{
*cluster = it.cluster;
*offset = it.offset;
closedir(&it);
return 0;
}
if (!fetch_next_entry(ef, ef->root, &it))
{
closedir(&it);
return -EIO;
}
}
}
int exfat_set_label(struct exfat* ef, const char* label)
{
le16_t label_utf16[EXFAT_ENAME_MAX + 1];
int rc;
cluster_t cluster;
off64_t offset;
struct exfat_entry_label entry;
memset(label_utf16, 0, sizeof(label_utf16));
rc = utf8_to_utf16(label_utf16, label, EXFAT_ENAME_MAX, strlen(label));
if (rc != 0)
return rc;
rc = find_label(ef, &cluster, &offset);
if (rc == -ENOENT)
rc = find_slot(ef, ef->root, &cluster, &offset, 1);
if (rc != 0)
return rc;
entry.type = EXFAT_ENTRY_LABEL;
entry.length = utf16_length(label_utf16);
memcpy(entry.name, label_utf16, sizeof(entry.name));
if (entry.length == 0)
entry.type ^= EXFAT_ENTRY_VALID;
if (exfat_pwrite(ef->dev, &entry, sizeof(struct exfat_entry_label),
co2o(ef, cluster, offset)) < 0)
{
exfat_error("failed to write label entry");
return -EIO;
}
strcpy(ef->label, label);
return 0;
}