diff options
Diffstat (limited to 'exfat/libexfat/node.c')
| -rw-r--r-- | exfat/libexfat/node.c | 1246 |
1 files changed, 1246 insertions, 0 deletions
diff --git a/exfat/libexfat/node.c b/exfat/libexfat/node.c new file mode 100644 index 000000000..e4fd32f31 --- /dev/null +++ b/exfat/libexfat/node.c @@ -0,0 +1,1246 @@ +/* + node.c (09.10.09) + exFAT file system implementation library. + + Free exFAT implementation. + Copyright (C) 2010-2015 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; + loff_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 loff_t co2o(struct exfat* ef, cluster_t cluster, loff_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)) + break; /* deleted entry, ignore it */ + if (!(entry->type & EXFAT_ENTRY_OPTIONAL)) + { + exfat_error("unknown entry type %#hhx", entry->type); + goto error; + } + /* optional entry, warn and skip */ + exfat_warn("unknown entry type %#hhx", entry->type); + if (continuations == 0) + { + exfat_error("unexpected continuation"); + goto error; + } + --continuations; + 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, loff_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; + loff_t offset; + loff_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 exfat_flush(ef); +} + +static bool erase_entry(struct exfat* ef, struct exfat_node* node) +{ + cluster_t cluster = node->entry_cluster; + loff_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, + loff_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; + loff_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, loff_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, loff_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; + loff_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_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, + loff_t new_offset) +{ + struct exfat_entry_meta1 meta1; + struct exfat_entry_meta2 meta2; + cluster_t old_cluster = node->entry_cluster; + loff_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; + loff_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, loff_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; + loff_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; +} |