diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/ext2/dir.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/ext2/dir.c | 733 |
1 files changed, 0 insertions, 733 deletions
diff --git a/ANDROID_3.4.5/fs/ext2/dir.c b/ANDROID_3.4.5/fs/ext2/dir.c deleted file mode 100644 index 0f4f5c92..00000000 --- a/ANDROID_3.4.5/fs/ext2/dir.c +++ /dev/null @@ -1,733 +0,0 @@ -/* - * linux/fs/ext2/dir.c - * - * Copyright (C) 1992, 1993, 1994, 1995 - * Remy Card (card@masi.ibp.fr) - * Laboratoire MASI - Institut Blaise Pascal - * Universite Pierre et Marie Curie (Paris VI) - * - * from - * - * linux/fs/minix/dir.c - * - * Copyright (C) 1991, 1992 Linus Torvalds - * - * ext2 directory handling functions - * - * Big-endian to little-endian byte-swapping/bitmaps by - * David S. Miller (davem@caip.rutgers.edu), 1995 - * - * All code that works with directory layout had been switched to pagecache - * and moved here. AV - */ - -#include "ext2.h" -#include <linux/buffer_head.h> -#include <linux/pagemap.h> -#include <linux/swap.h> - -typedef struct ext2_dir_entry_2 ext2_dirent; - -/* - * Tests against MAX_REC_LEN etc were put in place for 64k block - * sizes; if that is not possible on this arch, we can skip - * those tests and speed things up. - */ -static inline unsigned ext2_rec_len_from_disk(__le16 dlen) -{ - unsigned len = le16_to_cpu(dlen); - -#if (PAGE_CACHE_SIZE >= 65536) - if (len == EXT2_MAX_REC_LEN) - return 1 << 16; -#endif - return len; -} - -static inline __le16 ext2_rec_len_to_disk(unsigned len) -{ -#if (PAGE_CACHE_SIZE >= 65536) - if (len == (1 << 16)) - return cpu_to_le16(EXT2_MAX_REC_LEN); - else - BUG_ON(len > (1 << 16)); -#endif - return cpu_to_le16(len); -} - -/* - * ext2 uses block-sized chunks. Arguably, sector-sized ones would be - * more robust, but we have what we have - */ -static inline unsigned ext2_chunk_size(struct inode *inode) -{ - return inode->i_sb->s_blocksize; -} - -static inline void ext2_put_page(struct page *page) -{ - kunmap(page); - page_cache_release(page); -} - -static inline unsigned long dir_pages(struct inode *inode) -{ - return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT; -} - -/* - * Return the offset into page `page_nr' of the last valid - * byte in that page, plus one. - */ -static unsigned -ext2_last_byte(struct inode *inode, unsigned long page_nr) -{ - unsigned last_byte = inode->i_size; - - last_byte -= page_nr << PAGE_CACHE_SHIFT; - if (last_byte > PAGE_CACHE_SIZE) - last_byte = PAGE_CACHE_SIZE; - return last_byte; -} - -static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len) -{ - struct address_space *mapping = page->mapping; - struct inode *dir = mapping->host; - int err = 0; - - dir->i_version++; - block_write_end(NULL, mapping, pos, len, len, page, NULL); - - if (pos+len > dir->i_size) { - i_size_write(dir, pos+len); - mark_inode_dirty(dir); - } - - if (IS_DIRSYNC(dir)) { - err = write_one_page(page, 1); - if (!err) - err = sync_inode_metadata(dir, 1); - } else { - unlock_page(page); - } - - return err; -} - -static void ext2_check_page(struct page *page, int quiet) -{ - struct inode *dir = page->mapping->host; - struct super_block *sb = dir->i_sb; - unsigned chunk_size = ext2_chunk_size(dir); - char *kaddr = page_address(page); - u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count); - unsigned offs, rec_len; - unsigned limit = PAGE_CACHE_SIZE; - ext2_dirent *p; - char *error; - - if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) { - limit = dir->i_size & ~PAGE_CACHE_MASK; - if (limit & (chunk_size - 1)) - goto Ebadsize; - if (!limit) - goto out; - } - for (offs = 0; offs <= limit - EXT2_DIR_REC_LEN(1); offs += rec_len) { - p = (ext2_dirent *)(kaddr + offs); - rec_len = ext2_rec_len_from_disk(p->rec_len); - - if (unlikely(rec_len < EXT2_DIR_REC_LEN(1))) - goto Eshort; - if (unlikely(rec_len & 3)) - goto Ealign; - if (unlikely(rec_len < EXT2_DIR_REC_LEN(p->name_len))) - goto Enamelen; - if (unlikely(((offs + rec_len - 1) ^ offs) & ~(chunk_size-1))) - goto Espan; - if (unlikely(le32_to_cpu(p->inode) > max_inumber)) - goto Einumber; - } - if (offs != limit) - goto Eend; -out: - SetPageChecked(page); - return; - - /* Too bad, we had an error */ - -Ebadsize: - if (!quiet) - ext2_error(sb, __func__, - "size of directory #%lu is not a multiple " - "of chunk size", dir->i_ino); - goto fail; -Eshort: - error = "rec_len is smaller than minimal"; - goto bad_entry; -Ealign: - error = "unaligned directory entry"; - goto bad_entry; -Enamelen: - error = "rec_len is too small for name_len"; - goto bad_entry; -Espan: - error = "directory entry across blocks"; - goto bad_entry; -Einumber: - error = "inode out of bounds"; -bad_entry: - if (!quiet) - ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - " - "offset=%lu, inode=%lu, rec_len=%d, name_len=%d", - dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs, - (unsigned long) le32_to_cpu(p->inode), - rec_len, p->name_len); - goto fail; -Eend: - if (!quiet) { - p = (ext2_dirent *)(kaddr + offs); - ext2_error(sb, "ext2_check_page", - "entry in directory #%lu spans the page boundary" - "offset=%lu, inode=%lu", - dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs, - (unsigned long) le32_to_cpu(p->inode)); - } -fail: - SetPageChecked(page); - SetPageError(page); -} - -static struct page * ext2_get_page(struct inode *dir, unsigned long n, - int quiet) -{ - struct address_space *mapping = dir->i_mapping; - struct page *page = read_mapping_page(mapping, n, NULL); - if (!IS_ERR(page)) { - kmap(page); - if (!PageChecked(page)) - ext2_check_page(page, quiet); - if (PageError(page)) - goto fail; - } - return page; - -fail: - ext2_put_page(page); - return ERR_PTR(-EIO); -} - -/* - * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure. - * - * len <= EXT2_NAME_LEN and de != NULL are guaranteed by caller. - */ -static inline int ext2_match (int len, const char * const name, - struct ext2_dir_entry_2 * de) -{ - if (len != de->name_len) - return 0; - if (!de->inode) - return 0; - return !memcmp(name, de->name, len); -} - -/* - * p is at least 6 bytes before the end of page - */ -static inline ext2_dirent *ext2_next_entry(ext2_dirent *p) -{ - return (ext2_dirent *)((char *)p + - ext2_rec_len_from_disk(p->rec_len)); -} - -static inline unsigned -ext2_validate_entry(char *base, unsigned offset, unsigned mask) -{ - ext2_dirent *de = (ext2_dirent*)(base + offset); - ext2_dirent *p = (ext2_dirent*)(base + (offset&mask)); - while ((char*)p < (char*)de) { - if (p->rec_len == 0) - break; - p = ext2_next_entry(p); - } - return (char *)p - base; -} - -static unsigned char ext2_filetype_table[EXT2_FT_MAX] = { - [EXT2_FT_UNKNOWN] = DT_UNKNOWN, - [EXT2_FT_REG_FILE] = DT_REG, - [EXT2_FT_DIR] = DT_DIR, - [EXT2_FT_CHRDEV] = DT_CHR, - [EXT2_FT_BLKDEV] = DT_BLK, - [EXT2_FT_FIFO] = DT_FIFO, - [EXT2_FT_SOCK] = DT_SOCK, - [EXT2_FT_SYMLINK] = DT_LNK, -}; - -#define S_SHIFT 12 -static unsigned char ext2_type_by_mode[S_IFMT >> S_SHIFT] = { - [S_IFREG >> S_SHIFT] = EXT2_FT_REG_FILE, - [S_IFDIR >> S_SHIFT] = EXT2_FT_DIR, - [S_IFCHR >> S_SHIFT] = EXT2_FT_CHRDEV, - [S_IFBLK >> S_SHIFT] = EXT2_FT_BLKDEV, - [S_IFIFO >> S_SHIFT] = EXT2_FT_FIFO, - [S_IFSOCK >> S_SHIFT] = EXT2_FT_SOCK, - [S_IFLNK >> S_SHIFT] = EXT2_FT_SYMLINK, -}; - -static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode) -{ - umode_t mode = inode->i_mode; - if (EXT2_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT2_FEATURE_INCOMPAT_FILETYPE)) - de->file_type = ext2_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; - else - de->file_type = 0; -} - -static int -ext2_readdir (struct file * filp, void * dirent, filldir_t filldir) -{ - loff_t pos = filp->f_pos; - struct inode *inode = filp->f_path.dentry->d_inode; - struct super_block *sb = inode->i_sb; - unsigned int offset = pos & ~PAGE_CACHE_MASK; - unsigned long n = pos >> PAGE_CACHE_SHIFT; - unsigned long npages = dir_pages(inode); - unsigned chunk_mask = ~(ext2_chunk_size(inode)-1); - unsigned char *types = NULL; - int need_revalidate = filp->f_version != inode->i_version; - - if (pos > inode->i_size - EXT2_DIR_REC_LEN(1)) - return 0; - - if (EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE)) - types = ext2_filetype_table; - - for ( ; n < npages; n++, offset = 0) { - char *kaddr, *limit; - ext2_dirent *de; - struct page *page = ext2_get_page(inode, n, 0); - - if (IS_ERR(page)) { - ext2_error(sb, __func__, - "bad page in #%lu", - inode->i_ino); - filp->f_pos += PAGE_CACHE_SIZE - offset; - return PTR_ERR(page); - } - kaddr = page_address(page); - if (unlikely(need_revalidate)) { - if (offset) { - offset = ext2_validate_entry(kaddr, offset, chunk_mask); - filp->f_pos = (n<<PAGE_CACHE_SHIFT) + offset; - } - filp->f_version = inode->i_version; - need_revalidate = 0; - } - de = (ext2_dirent *)(kaddr+offset); - limit = kaddr + ext2_last_byte(inode, n) - EXT2_DIR_REC_LEN(1); - for ( ;(char*)de <= limit; de = ext2_next_entry(de)) { - if (de->rec_len == 0) { - ext2_error(sb, __func__, - "zero-length directory entry"); - ext2_put_page(page); - return -EIO; - } - if (de->inode) { - int over; - unsigned char d_type = DT_UNKNOWN; - - if (types && de->file_type < EXT2_FT_MAX) - d_type = types[de->file_type]; - - offset = (char *)de - kaddr; - over = filldir(dirent, de->name, de->name_len, - (n<<PAGE_CACHE_SHIFT) | offset, - le32_to_cpu(de->inode), d_type); - if (over) { - ext2_put_page(page); - return 0; - } - } - filp->f_pos += ext2_rec_len_from_disk(de->rec_len); - } - ext2_put_page(page); - } - return 0; -} - -/* - * ext2_find_entry() - * - * finds an entry in the specified directory with the wanted name. It - * returns the page in which the entry was found (as a parameter - res_page), - * and the entry itself. Page is returned mapped and unlocked. - * Entry is guaranteed to be valid. - */ -struct ext2_dir_entry_2 *ext2_find_entry (struct inode * dir, - struct qstr *child, struct page ** res_page) -{ - const char *name = child->name; - int namelen = child->len; - unsigned reclen = EXT2_DIR_REC_LEN(namelen); - unsigned long start, n; - unsigned long npages = dir_pages(dir); - struct page *page = NULL; - struct ext2_inode_info *ei = EXT2_I(dir); - ext2_dirent * de; - int dir_has_error = 0; - - if (npages == 0) - goto out; - - /* OFFSET_CACHE */ - *res_page = NULL; - - start = ei->i_dir_start_lookup; - if (start >= npages) - start = 0; - n = start; - do { - char *kaddr; - page = ext2_get_page(dir, n, dir_has_error); - if (!IS_ERR(page)) { - kaddr = page_address(page); - de = (ext2_dirent *) kaddr; - kaddr += ext2_last_byte(dir, n) - reclen; - while ((char *) de <= kaddr) { - if (de->rec_len == 0) { - ext2_error(dir->i_sb, __func__, - "zero-length directory entry"); - ext2_put_page(page); - goto out; - } - if (ext2_match (namelen, name, de)) - goto found; - de = ext2_next_entry(de); - } - ext2_put_page(page); - } else - dir_has_error = 1; - - if (++n >= npages) - n = 0; - /* next page is past the blocks we've got */ - if (unlikely(n > (dir->i_blocks >> (PAGE_CACHE_SHIFT - 9)))) { - ext2_error(dir->i_sb, __func__, - "dir %lu size %lld exceeds block count %llu", - dir->i_ino, dir->i_size, - (unsigned long long)dir->i_blocks); - goto out; - } - } while (n != start); -out: - return NULL; - -found: - *res_page = page; - ei->i_dir_start_lookup = n; - return de; -} - -struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p) -{ - struct page *page = ext2_get_page(dir, 0, 0); - ext2_dirent *de = NULL; - - if (!IS_ERR(page)) { - de = ext2_next_entry((ext2_dirent *) page_address(page)); - *p = page; - } - return de; -} - -ino_t ext2_inode_by_name(struct inode *dir, struct qstr *child) -{ - ino_t res = 0; - struct ext2_dir_entry_2 *de; - struct page *page; - - de = ext2_find_entry (dir, child, &page); - if (de) { - res = le32_to_cpu(de->inode); - ext2_put_page(page); - } - return res; -} - -static int ext2_prepare_chunk(struct page *page, loff_t pos, unsigned len) -{ - return __block_write_begin(page, pos, len, ext2_get_block); -} - -/* Releases the page */ -void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de, - struct page *page, struct inode *inode, int update_times) -{ - loff_t pos = page_offset(page) + - (char *) de - (char *) page_address(page); - unsigned len = ext2_rec_len_from_disk(de->rec_len); - int err; - - lock_page(page); - err = ext2_prepare_chunk(page, pos, len); - BUG_ON(err); - de->inode = cpu_to_le32(inode->i_ino); - ext2_set_de_type(de, inode); - err = ext2_commit_chunk(page, pos, len); - ext2_put_page(page); - if (update_times) - dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC; - EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL; - mark_inode_dirty(dir); -} - -/* - * Parent is locked. - */ -int ext2_add_link (struct dentry *dentry, struct inode *inode) -{ - struct inode *dir = dentry->d_parent->d_inode; - const char *name = dentry->d_name.name; - int namelen = dentry->d_name.len; - unsigned chunk_size = ext2_chunk_size(dir); - unsigned reclen = EXT2_DIR_REC_LEN(namelen); - unsigned short rec_len, name_len; - struct page *page = NULL; - ext2_dirent * de; - unsigned long npages = dir_pages(dir); - unsigned long n; - char *kaddr; - loff_t pos; - int err; - - /* - * We take care of directory expansion in the same loop. - * This code plays outside i_size, so it locks the page - * to protect that region. - */ - for (n = 0; n <= npages; n++) { - char *dir_end; - - page = ext2_get_page(dir, n, 0); - err = PTR_ERR(page); - if (IS_ERR(page)) - goto out; - lock_page(page); - kaddr = page_address(page); - dir_end = kaddr + ext2_last_byte(dir, n); - de = (ext2_dirent *)kaddr; - kaddr += PAGE_CACHE_SIZE - reclen; - while ((char *)de <= kaddr) { - if ((char *)de == dir_end) { - /* We hit i_size */ - name_len = 0; - rec_len = chunk_size; - de->rec_len = ext2_rec_len_to_disk(chunk_size); - de->inode = 0; - goto got_it; - } - if (de->rec_len == 0) { - ext2_error(dir->i_sb, __func__, - "zero-length directory entry"); - err = -EIO; - goto out_unlock; - } - err = -EEXIST; - if (ext2_match (namelen, name, de)) - goto out_unlock; - name_len = EXT2_DIR_REC_LEN(de->name_len); - rec_len = ext2_rec_len_from_disk(de->rec_len); - if (!de->inode && rec_len >= reclen) - goto got_it; - if (rec_len >= name_len + reclen) - goto got_it; - de = (ext2_dirent *) ((char *) de + rec_len); - } - unlock_page(page); - ext2_put_page(page); - } - BUG(); - return -EINVAL; - -got_it: - pos = page_offset(page) + - (char*)de - (char*)page_address(page); - err = ext2_prepare_chunk(page, pos, rec_len); - if (err) - goto out_unlock; - if (de->inode) { - ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len); - de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len); - de->rec_len = ext2_rec_len_to_disk(name_len); - de = de1; - } - de->name_len = namelen; - memcpy(de->name, name, namelen); - de->inode = cpu_to_le32(inode->i_ino); - ext2_set_de_type (de, inode); - err = ext2_commit_chunk(page, pos, rec_len); - dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC; - EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL; - mark_inode_dirty(dir); - /* OFFSET_CACHE */ -out_put: - ext2_put_page(page); -out: - return err; -out_unlock: - unlock_page(page); - goto out_put; -} - -/* - * ext2_delete_entry deletes a directory entry by merging it with the - * previous entry. Page is up-to-date. Releases the page. - */ -int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page ) -{ - struct inode *inode = page->mapping->host; - char *kaddr = page_address(page); - unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1); - unsigned to = ((char *)dir - kaddr) + - ext2_rec_len_from_disk(dir->rec_len); - loff_t pos; - ext2_dirent * pde = NULL; - ext2_dirent * de = (ext2_dirent *) (kaddr + from); - int err; - - while ((char*)de < (char*)dir) { - if (de->rec_len == 0) { - ext2_error(inode->i_sb, __func__, - "zero-length directory entry"); - err = -EIO; - goto out; - } - pde = de; - de = ext2_next_entry(de); - } - if (pde) - from = (char*)pde - (char*)page_address(page); - pos = page_offset(page) + from; - lock_page(page); - err = ext2_prepare_chunk(page, pos, to - from); - BUG_ON(err); - if (pde) - pde->rec_len = ext2_rec_len_to_disk(to - from); - dir->inode = 0; - err = ext2_commit_chunk(page, pos, to - from); - inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; - EXT2_I(inode)->i_flags &= ~EXT2_BTREE_FL; - mark_inode_dirty(inode); -out: - ext2_put_page(page); - return err; -} - -/* - * Set the first fragment of directory. - */ -int ext2_make_empty(struct inode *inode, struct inode *parent) -{ - struct page *page = grab_cache_page(inode->i_mapping, 0); - unsigned chunk_size = ext2_chunk_size(inode); - struct ext2_dir_entry_2 * de; - int err; - void *kaddr; - - if (!page) - return -ENOMEM; - - err = ext2_prepare_chunk(page, 0, chunk_size); - if (err) { - unlock_page(page); - goto fail; - } - kaddr = kmap_atomic(page); - memset(kaddr, 0, chunk_size); - de = (struct ext2_dir_entry_2 *)kaddr; - de->name_len = 1; - de->rec_len = ext2_rec_len_to_disk(EXT2_DIR_REC_LEN(1)); - memcpy (de->name, ".\0\0", 4); - de->inode = cpu_to_le32(inode->i_ino); - ext2_set_de_type (de, inode); - - de = (struct ext2_dir_entry_2 *)(kaddr + EXT2_DIR_REC_LEN(1)); - de->name_len = 2; - de->rec_len = ext2_rec_len_to_disk(chunk_size - EXT2_DIR_REC_LEN(1)); - de->inode = cpu_to_le32(parent->i_ino); - memcpy (de->name, "..\0", 4); - ext2_set_de_type (de, inode); - kunmap_atomic(kaddr); - err = ext2_commit_chunk(page, 0, chunk_size); -fail: - page_cache_release(page); - return err; -} - -/* - * routine to check that the specified directory is empty (for rmdir) - */ -int ext2_empty_dir (struct inode * inode) -{ - struct page *page = NULL; - unsigned long i, npages = dir_pages(inode); - int dir_has_error = 0; - - for (i = 0; i < npages; i++) { - char *kaddr; - ext2_dirent * de; - page = ext2_get_page(inode, i, dir_has_error); - - if (IS_ERR(page)) { - dir_has_error = 1; - continue; - } - - kaddr = page_address(page); - de = (ext2_dirent *)kaddr; - kaddr += ext2_last_byte(inode, i) - EXT2_DIR_REC_LEN(1); - - while ((char *)de <= kaddr) { - if (de->rec_len == 0) { - ext2_error(inode->i_sb, __func__, - "zero-length directory entry"); - printk("kaddr=%p, de=%p\n", kaddr, de); - goto not_empty; - } - if (de->inode != 0) { - /* check for . and .. */ - if (de->name[0] != '.') - goto not_empty; - if (de->name_len > 2) - goto not_empty; - if (de->name_len < 2) { - if (de->inode != - cpu_to_le32(inode->i_ino)) - goto not_empty; - } else if (de->name[1] != '.') - goto not_empty; - } - de = ext2_next_entry(de); - } - ext2_put_page(page); - } - return 1; - -not_empty: - ext2_put_page(page); - return 0; -} - -const struct file_operations ext2_dir_operations = { - .llseek = generic_file_llseek, - .read = generic_read_dir, - .readdir = ext2_readdir, - .unlocked_ioctl = ext2_ioctl, -#ifdef CONFIG_COMPAT - .compat_ioctl = ext2_compat_ioctl, -#endif - .fsync = ext2_fsync, -}; |