]> git.sven.stormbind.net Git - sven/exfat-utils.git/blobdiff - libexfat/node.c
Imported Upstream version 0.9.8
[sven/exfat-utils.git] / libexfat / node.c
index fa9e572632d545ab564a27224ef84009be405811..4cbb3e2d6d06f976d9e1097726662cb8a3e1056e 100644 (file)
@@ -2,7 +2,7 @@
        node.c (09.10.09)
        exFAT file system implementation library.
 
-       Copyright (C) 2009, 2010  Andrew Nayenko
+       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
@@ -86,8 +86,8 @@ static int opendir(struct exfat* ef, const struct exfat_node* dir,
                exfat_error("out of memory");
                return -ENOMEM;
        }
-       exfat_read_raw(it->chunk, CLUSTER_SIZE(*ef->sb),
-                       exfat_c2o(ef, it->cluster), ef->fd);
+       exfat_pread(ef->dev, it->chunk, CLUSTER_SIZE(*ef->sb),
+                       exfat_c2o(ef, it->cluster));
        return 0;
 }
 
@@ -108,14 +108,18 @@ static int fetch_next_entry(struct exfat* ef, const struct exfat_node* parent,
        /* 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 0;
                it->cluster = exfat_next_cluster(ef, parent, it->cluster);
                if (CLUSTER_INVALID(it->cluster))
                {
                        exfat_error("invalid cluster while reading directory");
                        return 1;
                }
-               exfat_read_raw(it->chunk, CLUSTER_SIZE(*ef->sb),
-                               exfat_c2o(ef, it->cluster), ef->fd);
+               exfat_pread(ef->dev, it->chunk, CLUSTER_SIZE(*ef->sb),
+                               exfat_c2o(ef, it->cluster));
        }
        return 0;
 }
@@ -166,6 +170,7 @@ static const struct exfat_entry* get_entry_ptr(const struct exfat* ef,
 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;
@@ -182,21 +187,19 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
 
        for (;;)
        {
-               /* every directory (even empty one) occupies at least one cluster and
-                  must contain EOD entry */
-               entry = get_entry_ptr(ef, it);
-
-               switch (entry->type)
+               if (it->offset >= parent->size)
                {
-               case EXFAT_ENTRY_EOD:
                        if (continuations != 0)
                        {
-                               exfat_error("expected %hhu continuations before EOD",
-                                               continuations);
+                               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)
                        {
@@ -211,13 +214,16 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
                        if (continuations < 2)
                        {
                                exfat_error("too few continuations (%hhu)", continuations);
-                               return -EIO;
+                               goto error;
                        }
                        reference_checksum = le16_to_cpu(meta1->checksum);
                        actual_checksum = exfat_start_checksum(meta1);
                        *node = allocate_node();
                        if (*node == NULL)
-                               return -ENOMEM;
+                       {
+                               rc = -ENOMEM;
+                               goto error;
+                       }
                        /* new node has zero reference counter */
                        (*node)->entry_cluster = it->cluster;
                        (*node)->entry_offset = it->offset;
@@ -290,7 +296,7 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
                                {
                                        exfat_error("invalid checksum (0x%hx != 0x%hx)",
                                                        actual_checksum, reference_checksum);
-                                       return -EIO;
+                                       goto error;
                                }
                                if (fetch_next_entry(ef, parent, it) != 0)
                                        goto error;
@@ -305,7 +311,7 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
                        if (CLUSTER_INVALID(le32_to_cpu(upcase->start_cluster)))
                        {
                                exfat_error("invalid cluster in upcase table");
-                               return -EIO;
+                               goto error;
                        }
                        if (le64_to_cpu(upcase->size) == 0 ||
                                le64_to_cpu(upcase->size) > 0xffff * sizeof(uint16_t) ||
@@ -313,19 +319,20 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
                        {
                                exfat_error("bad upcase table size (%"PRIu64" bytes)",
                                                le64_to_cpu(upcase->size));
-                               return -EIO;
+                               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));
-                               return -ENOMEM;
+                               rc = -ENOMEM;
+                               goto error;
                        }
                        ef->upcase_chars = le64_to_cpu(upcase->size) / sizeof(le16_t);
 
-                       exfat_read_raw(ef->upcase, le64_to_cpu(upcase->size),
-                                       exfat_c2o(ef, le32_to_cpu(upcase->start_cluster)), ef->fd);
+                       exfat_pread(ef->dev, ef->upcase, le64_to_cpu(upcase->size),
+                                       exfat_c2o(ef, le32_to_cpu(upcase->start_cluster)));
                        break;
 
                case EXFAT_ENTRY_BITMAP:
@@ -333,7 +340,7 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
                        if (CLUSTER_INVALID(le32_to_cpu(bitmap->start_cluster)))
                        {
                                exfat_error("invalid cluster in clusters bitmap");
-                               return -EIO;
+                               goto error;
                        }
                        ef->cmap.size = le32_to_cpu(ef->sb->cluster_count) -
                                EXFAT_FIRST_DATA_CLUSTER;
@@ -342,7 +349,7 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
                                exfat_error("invalid clusters bitmap size: %"PRIu64
                                                " (expected at least %u)",
                                                le64_to_cpu(bitmap->size), (ef->cmap.size + 7) / 8);
-                               return -EIO;
+                               goto error;
                        }
                        ef->cmap.start_cluster = le32_to_cpu(bitmap->start_cluster);
                        /* FIXME bitmap can be rather big, up to 512 MB */
@@ -352,11 +359,12 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
                        {
                                exfat_error("failed to allocate clusters bitmap chunk "
                                                "(%"PRIu64" bytes)", le64_to_cpu(bitmap->size));
-                               return -ENOMEM;
+                               rc = -ENOMEM;
+                               goto error;
                        }
 
-                       exfat_read_raw(ef->cmap.chunk, le64_to_cpu(bitmap->size),
-                                       exfat_c2o(ef, ef->cmap.start_cluster), ef->fd);
+                       exfat_pread(ef->dev, ef->cmap.chunk, le64_to_cpu(bitmap->size),
+                                       exfat_c2o(ef, ef->cmap.start_cluster));
                        break;
 
                case EXFAT_ENTRY_LABEL:
@@ -364,11 +372,11 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
                        if (label->length > EXFAT_ENAME_MAX)
                        {
                                exfat_error("too long label (%hhu chars)", label->length);
-                               return -EIO;
+                               goto error;
                        }
                        if (utf16_to_utf8(ef->label, label->name,
                                                sizeof(ef->label), EXFAT_ENAME_MAX) != 0)
-                               return -EIO;
+                               goto error;
                        break;
 
                default:
@@ -388,7 +396,7 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
 error:
        free(*node);
        *node = NULL;
-       return -EIO;
+       return rc;
 }
 
 int exfat_cache_directory(struct exfat* ef, struct exfat_node* dir)
@@ -493,14 +501,14 @@ void exfat_flush_node(struct exfat* ef, struct exfat_node* node)
        next_entry(ef, node->parent, &cluster, &offset);
        meta2_offset = co2o(ef, cluster, offset);
 
-       exfat_read_raw(&meta1, sizeof(meta1), meta1_offset, ef->fd);
+       exfat_pread(ef->dev, &meta1, sizeof(meta1), meta1_offset);
        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);
+       exfat_pread(ef->dev, &meta2, sizeof(meta2), meta2_offset);
        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);
@@ -513,8 +521,8 @@ void exfat_flush_node(struct exfat* ef, struct exfat_node* node)
 
        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);
+       exfat_pwrite(ef->dev, &meta1, sizeof(meta1), meta1_offset);
+       exfat_pwrite(ef->dev, &meta2, sizeof(meta2), meta2_offset);
 
        node->flags &= ~EXFAT_ATTRIB_DIRTY;
 }
@@ -527,17 +535,17 @@ static void erase_entry(struct exfat* ef, struct exfat_node* node)
        uint8_t entry_type;
 
        entry_type = EXFAT_ENTRY_FILE & ~EXFAT_ENTRY_VALID;
-       exfat_write_raw(&entry_type, 1, co2o(ef, cluster, offset), ef->fd);
+       exfat_pwrite(ef->dev, &entry_type, 1, co2o(ef, cluster, offset));
 
        next_entry(ef, node->parent, &cluster, &offset);
        entry_type = EXFAT_ENTRY_FILE_INFO & ~EXFAT_ENTRY_VALID;
-       exfat_write_raw(&entry_type, 1, co2o(ef, cluster, offset), ef->fd);
+       exfat_pwrite(ef->dev, &entry_type, 1, co2o(ef, cluster, offset));
 
        while (name_entries--)
        {
                next_entry(ef, node->parent, &cluster, &offset);
                entry_type = EXFAT_ENTRY_FILE_NAME & ~EXFAT_ENTRY_VALID;
-               exfat_write_raw(&entry_type, 1, co2o(ef, cluster, offset), ef->fd);
+               exfat_pwrite(ef->dev, &entry_type, 1, co2o(ef, cluster, offset));
        }
 }
 
@@ -570,10 +578,8 @@ static int shrink_directory(struct exfat* ef, struct exfat_node* dir,
 {
        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 entries = 0;
        uint64_t new_size;
-       struct exfat_entry eod;
-       off_t eod_offset;
        int rc;
 
        if (!(dir->flags & EXFAT_ATTRIB_DIR))
@@ -606,21 +612,13 @@ static int shrink_directory(struct exfat* ef, struct exfat_node* dir,
 
        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);
        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;
 }
 
@@ -686,24 +684,22 @@ static int find_slot(struct exfat* ef, struct exfat_node* dir,
                        *offset = it.offset;
                }
                entry = get_entry_ptr(ef, &it);
-               if (entry->type == EXFAT_ENTRY_EOD)
+               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,
-                                       it.offset + sizeof(struct exfat_entry), /* actual size */
+                       rc = grow_directory(ef, dir, dir->size,
                                        (subentries - contiguous) * sizeof(struct exfat_entry));
                        if (rc != 0)
                        {
                                closedir(&it);
                                return rc;
                        }
-                       break;
                }
-               if (entry->type & EXFAT_ENTRY_VALID)
-                       contiguous = 0;
-               else
-                       contiguous++;
-               if (contiguous == subentries)
-                       break;  /* suitable slot is found */
                if (fetch_next_entry(ef, dir, &it) != 0)
                {
                        closedir(&it);
@@ -739,8 +735,7 @@ static int write_entry(struct exfat* ef, struct exfat_node* dir,
                        &meta1.crtime_cs);
        meta1.adate = meta1.mdate = meta1.crdate;
        meta1.atime = meta1.mtime = meta1.crtime;
-       /* crtime_cs and mtime_cs contain addition to the time in centiseconds;
-          just ignore those fields because we operate with 2 sec resolution */
+       meta1.mtime_cs = meta1.crtime_cs; /* there is no atime_cs */
 
        memset(&meta2, 0, sizeof(meta2));
        meta2.type = EXFAT_ENTRY_FILE_INFO;
@@ -751,17 +746,17 @@ static int write_entry(struct exfat* ef, struct exfat_node* dir,
 
        meta1.checksum = exfat_calc_checksum(&meta1, &meta2, node->name);
 
-       exfat_write_raw(&meta1, sizeof(meta1), co2o(ef, cluster, offset), ef->fd);
+       exfat_pwrite(ef->dev, &meta1, sizeof(meta1), co2o(ef, cluster, offset));
        next_entry(ef, dir, &cluster, &offset);
-       exfat_write_raw(&meta2, sizeof(meta2), co2o(ef, cluster, offset), ef->fd);
+       exfat_pwrite(ef->dev, &meta2, sizeof(meta2), co2o(ef, cluster, offset));
        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,
                                EXFAT_ENAME_MAX * sizeof(le16_t));
                next_entry(ef, dir, &cluster, &offset);
-               exfat_write_raw(&name_entry, sizeof(name_entry),
-                               co2o(ef, cluster, offset), ef->fd);
+               exfat_pwrite(ef->dev, &name_entry, sizeof(name_entry),
+                               co2o(ef, cluster, offset));
        }
 
        init_node_meta1(node, &meta1);
@@ -843,11 +838,11 @@ static void rename_entry(struct exfat* ef, struct exfat_node* dir,
        const int name_entries = DIV_ROUND_UP(name_length, EXFAT_ENAME_MAX);
        int i;
 
-       exfat_read_raw(&meta1, sizeof(meta1), co2o(ef, old_cluster, old_offset),
-                       ef->fd);
+       exfat_pread(ef->dev, &meta1, sizeof(meta1),
+                       co2o(ef, old_cluster, old_offset));
        next_entry(ef, node->parent, &old_cluster, &old_offset);
-       exfat_read_raw(&meta2, sizeof(meta2), co2o(ef, old_cluster, old_offset),
-                       ef->fd);
+       exfat_pread(ef->dev, &meta2, sizeof(meta2),
+                       co2o(ef, old_cluster, old_offset));
        meta1.continuations = 1 + name_entries;
        meta2.name_hash = exfat_calc_name_hash(ef, name);
        meta2.name_length = name_length;
@@ -858,11 +853,11 @@ static void rename_entry(struct exfat* ef, struct exfat_node* dir,
        node->entry_cluster = new_cluster;
        node->entry_offset = new_offset;
 
-       exfat_write_raw(&meta1, sizeof(meta1), co2o(ef, new_cluster, new_offset),
-                       ef->fd);
+       exfat_pwrite(ef->dev, &meta1, sizeof(meta1),
+                       co2o(ef, new_cluster, new_offset));
        next_entry(ef, dir, &new_cluster, &new_offset);
-       exfat_write_raw(&meta2, sizeof(meta2), co2o(ef, new_cluster, new_offset),
-                       ef->fd);
+       exfat_pwrite(ef->dev, &meta2, sizeof(meta2),
+                       co2o(ef, new_cluster, new_offset));
 
        for (i = 0; i < name_entries; i++)
        {
@@ -870,8 +865,8 @@ static void rename_entry(struct exfat* ef, struct exfat_node* dir,
                memcpy(name_entry.name, name + i * EXFAT_ENAME_MAX,
                                EXFAT_ENAME_MAX * sizeof(le16_t));
                next_entry(ef, dir, &new_cluster, &new_offset);
-               exfat_write_raw(&name_entry, sizeof(name_entry),
-                               co2o(ef, new_cluster, new_offset), ef->fd);
+               exfat_pwrite(ef->dev, &name_entry, sizeof(name_entry),
+                               co2o(ef, new_cluster, new_offset));
        }
 
        memcpy(node->name, name, (EXFAT_NAME_MAX + 1) * sizeof(le16_t));
@@ -966,7 +961,6 @@ static int find_label(struct exfat* ef, cluster_t* cluster, off_t* offset)
 {
        struct iterator it;
        int rc;
-       const struct exfat_entry* entry;
 
        rc = opendir(ef, ef->root, &it);
        if (rc != 0)
@@ -974,14 +968,13 @@ static int find_label(struct exfat* ef, cluster_t* cluster, off_t* offset)
 
        for (;;)
        {
-               entry = get_entry_ptr(ef, &it);
-
-               if (entry->type == EXFAT_ENTRY_EOD)
+               if (it.offset >= ef->root->size)
                {
                        closedir(&it);
                        return -ENOENT;
                }
-               if (entry->type == EXFAT_ENTRY_LABEL)
+
+               if (get_entry_ptr(ef, &it)->type == EXFAT_ENTRY_LABEL)
                {
                        *cluster = it.cluster;
                        *offset = it.offset;
@@ -1022,7 +1015,7 @@ int exfat_set_label(struct exfat* ef, const char* label)
        if (entry.length == 0)
                entry.type ^= EXFAT_ENTRY_VALID;
 
-       exfat_write_raw(&entry, sizeof(struct exfat_entry_label),
-                       co2o(ef, cluster, offset), ef->fd);
+       exfat_pwrite(ef->dev, &entry, sizeof(struct exfat_entry_label),
+                       co2o(ef, cluster, offset));
        return 0;
 }