From 31a18d570d968a01582bea900002a86d1c9e17e6 Mon Sep 17 00:00:00 2001 From: AKASHI Takahiro Date: Tue, 11 Sep 2018 15:59:10 +0900 Subject: [PATCH] fs: fat: support mkdir In this patch, mkdir support is added to FAT file system. A newly created directory contains only "." and ".." entries. Signed-off-by: AKASHI Takahiro Signed-off-by: Alexander Graf --- fs/fat/fat_write.c | 136 +++++++++++++++++++++++++++++++++++++++++++++ fs/fs.c | 3 +- include/fat.h | 1 + 3 files changed, 139 insertions(+), 1 deletion(-) diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c index 651c7866de..035469f31c 100644 --- a/fs/fat/fat_write.c +++ b/fs/fat/fat_write.c @@ -1183,3 +1183,139 @@ int file_fat_write(const char *filename, void *buffer, loff_t offset, { return file_fat_write_at(filename, offset, buffer, maxsize, actwrite); } + +int fat_mkdir(const char *new_dirname) +{ + dir_entry *retdent; + fsdata datablock = { .fatbuf = NULL, }; + fsdata *mydata = &datablock; + fat_itr *itr = NULL; + char *dirname_copy, *parent, *dirname; + char l_dirname[VFAT_MAXLEN_BYTES]; + int ret = -1; + loff_t actwrite; + unsigned int bytesperclust; + dir_entry *dotdent = NULL; + + dirname_copy = strdup(new_dirname); + if (!dirname_copy) + goto exit; + + split_filename(dirname_copy, &parent, &dirname); + if (!strlen(dirname)) { + ret = -EINVAL; + goto exit; + } + + if (normalize_longname(l_dirname, dirname)) { + printf("FAT: illegal filename (%s)\n", dirname); + ret = -EINVAL; + goto exit; + } + + itr = malloc_cache_aligned(sizeof(fat_itr)); + if (!itr) { + ret = -ENOMEM; + goto exit; + } + + ret = fat_itr_root(itr, &datablock); + if (ret) + goto exit; + + total_sector = datablock.total_sect; + + ret = fat_itr_resolve(itr, parent, TYPE_DIR); + if (ret) { + printf("%s: doesn't exist (%d)\n", parent, ret); + goto exit; + } + + retdent = find_directory_entry(itr, l_dirname); + + if (retdent) { + printf("%s: already exists\n", l_dirname); + ret = -EEXIST; + goto exit; + } else { + if (itr->is_root) { + /* root dir cannot have "." or ".." */ + if (!strcmp(l_dirname, ".") || + !strcmp(l_dirname, "..")) { + ret = -EINVAL; + goto exit; + } + } + + if (!itr->dent) { + printf("Error: allocating new dir entry\n"); + ret = -EIO; + goto exit; + } + + memset(itr->dent, 0, sizeof(*itr->dent)); + + /* Set short name to set alias checksum field in dir_slot */ + set_name(itr->dent, dirname); + fill_dir_slot(itr, dirname); + + /* Set attribute as archive for regular file */ + fill_dentry(itr->fsdata, itr->dent, dirname, 0, 0, + ATTR_DIR | ATTR_ARCH); + + retdent = itr->dent; + } + + /* Default entries */ + bytesperclust = mydata->clust_size * mydata->sect_size; + dotdent = malloc_cache_aligned(bytesperclust); + if (!dotdent) { + ret = -ENOMEM; + goto exit; + } + memset(dotdent, 0, bytesperclust); + + memcpy(dotdent[0].name, ". ", 8); + memcpy(dotdent[0].ext, " ", 3); + dotdent[0].attr = ATTR_DIR | ATTR_ARCH; + + memcpy(dotdent[1].name, ".. ", 8); + memcpy(dotdent[1].ext, " ", 3); + dotdent[1].attr = ATTR_DIR | ATTR_ARCH; + set_start_cluster(mydata, &dotdent[1], itr->start_clust); + + ret = set_contents(mydata, retdent, 0, (__u8 *)dotdent, + bytesperclust, &actwrite); + if (ret < 0) { + printf("Error: writing contents\n"); + goto exit; + } + /* Write twice for "." */ + set_start_cluster(mydata, &dotdent[0], START(retdent)); + ret = set_contents(mydata, retdent, 0, (__u8 *)dotdent, + bytesperclust, &actwrite); + if (ret < 0) { + printf("Error: writing contents\n"); + goto exit; + } + + /* Flush fat buffer */ + ret = flush_dirty_fat_buffer(mydata); + if (ret) { + printf("Error: flush fat buffer\n"); + goto exit; + } + + /* Write directory table to device */ + ret = set_cluster(mydata, itr->clust, itr->block, + mydata->clust_size * mydata->sect_size); + if (ret) + printf("Error: writing directory entry\n"); + +exit: + free(dirname_copy); + free(mydata->fatbuf); + free(itr); + free(dotdent); + return ret; +} diff --git a/fs/fs.c b/fs/fs.c index 62165d5c57..099540f38a 100644 --- a/fs/fs.c +++ b/fs/fs.c @@ -164,14 +164,15 @@ static struct fstype_info fstypes[] = { .read = fat_read_file, #ifdef CONFIG_FAT_WRITE .write = file_fat_write, + .mkdir = fat_mkdir, #else .write = fs_write_unsupported, + .mkdir = fs_mkdir_unsupported, #endif .uuid = fs_uuid_unsupported, .opendir = fat_opendir, .readdir = fat_readdir, .closedir = fat_closedir, - .mkdir = fs_mkdir_unsupported, }, #endif #ifdef CONFIG_FS_EXT4 diff --git a/include/fat.h b/include/fat.h index a236451add..0fe3eaa8f7 100644 --- a/include/fat.h +++ b/include/fat.h @@ -203,5 +203,6 @@ int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len, int fat_opendir(const char *filename, struct fs_dir_stream **dirsp); int fat_readdir(struct fs_dir_stream *dirs, struct fs_dirent **dentp); void fat_closedir(struct fs_dir_stream *dirs); +int fat_mkdir(const char *dirname); void fat_close(void); #endif /* _FAT_H_ */ -- 2.39.5