diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/nilfs2/dir.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/nilfs2/dir.c | 688 |
1 files changed, 0 insertions, 688 deletions
diff --git a/ANDROID_3.4.5/fs/nilfs2/dir.c b/ANDROID_3.4.5/fs/nilfs2/dir.c deleted file mode 100644 index df1a7fb2..00000000 --- a/ANDROID_3.4.5/fs/nilfs2/dir.c +++ /dev/null @@ -1,688 +0,0 @@ -/* - * dir.c - NILFS directory entry operations - * - * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. - * - * 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 St, Fifth Floor, Boston, MA 02110-1301 USA - * - * Modified for NILFS by Amagai Yoshiji <amagai@osrg.net> - */ -/* - * 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 <linux/pagemap.h> -#include "nilfs.h" -#include "page.h" - -/* - * nilfs uses block-sized chunks. Arguably, sector-sized ones would be - * more robust, but we have what we have - */ -static inline unsigned nilfs_chunk_size(struct inode *inode) -{ - return inode->i_sb->s_blocksize; -} - -static inline void nilfs_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 nilfs_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 nilfs_prepare_chunk(struct page *page, unsigned from, unsigned to) -{ - loff_t pos = page_offset(page) + from; - return __block_write_begin(page, pos, to - from, nilfs_get_block); -} - -static void nilfs_commit_chunk(struct page *page, - struct address_space *mapping, - unsigned from, unsigned to) -{ - struct inode *dir = mapping->host; - loff_t pos = page_offset(page) + from; - unsigned len = to - from; - unsigned nr_dirty, copied; - int err; - - nr_dirty = nilfs_page_count_clean_buffers(page, from, to); - copied = block_write_end(NULL, mapping, pos, len, len, page, NULL); - if (pos + copied > dir->i_size) - i_size_write(dir, pos + copied); - if (IS_DIRSYNC(dir)) - nilfs_set_transaction_flag(NILFS_TI_SYNC); - err = nilfs_set_file_dirty(dir, nr_dirty); - WARN_ON(err); /* do not happen */ - unlock_page(page); -} - -static void nilfs_check_page(struct page *page) -{ - struct inode *dir = page->mapping->host; - struct super_block *sb = dir->i_sb; - unsigned chunk_size = nilfs_chunk_size(dir); - char *kaddr = page_address(page); - unsigned offs, rec_len; - unsigned limit = PAGE_CACHE_SIZE; - struct nilfs_dir_entry *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 - NILFS_DIR_REC_LEN(1); offs += rec_len) { - p = (struct nilfs_dir_entry *)(kaddr + offs); - rec_len = nilfs_rec_len_from_disk(p->rec_len); - - if (rec_len < NILFS_DIR_REC_LEN(1)) - goto Eshort; - if (rec_len & 3) - goto Ealign; - if (rec_len < NILFS_DIR_REC_LEN(p->name_len)) - goto Enamelen; - if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)) - goto Espan; - } - if (offs != limit) - goto Eend; -out: - SetPageChecked(page); - return; - - /* Too bad, we had an error */ - -Ebadsize: - nilfs_error(sb, "nilfs_check_page", - "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"; -bad_entry: - nilfs_error(sb, "nilfs_check_page", "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) le64_to_cpu(p->inode), - rec_len, p->name_len); - goto fail; -Eend: - p = (struct nilfs_dir_entry *)(kaddr + offs); - nilfs_error(sb, "nilfs_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) le64_to_cpu(p->inode)); -fail: - SetPageChecked(page); - SetPageError(page); -} - -static struct page *nilfs_get_page(struct inode *dir, unsigned long n) -{ - 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)) - nilfs_check_page(page); - if (PageError(page)) - goto fail; - } - return page; - -fail: - nilfs_put_page(page); - return ERR_PTR(-EIO); -} - -/* - * NOTE! unlike strncmp, nilfs_match returns 1 for success, 0 for failure. - * - * len <= NILFS_NAME_LEN and de != NULL are guaranteed by caller. - */ -static int -nilfs_match(int len, const unsigned char *name, struct nilfs_dir_entry *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 struct nilfs_dir_entry *nilfs_next_entry(struct nilfs_dir_entry *p) -{ - return (struct nilfs_dir_entry *)((char *)p + - nilfs_rec_len_from_disk(p->rec_len)); -} - -static unsigned char -nilfs_filetype_table[NILFS_FT_MAX] = { - [NILFS_FT_UNKNOWN] = DT_UNKNOWN, - [NILFS_FT_REG_FILE] = DT_REG, - [NILFS_FT_DIR] = DT_DIR, - [NILFS_FT_CHRDEV] = DT_CHR, - [NILFS_FT_BLKDEV] = DT_BLK, - [NILFS_FT_FIFO] = DT_FIFO, - [NILFS_FT_SOCK] = DT_SOCK, - [NILFS_FT_SYMLINK] = DT_LNK, -}; - -#define S_SHIFT 12 -static unsigned char -nilfs_type_by_mode[S_IFMT >> S_SHIFT] = { - [S_IFREG >> S_SHIFT] = NILFS_FT_REG_FILE, - [S_IFDIR >> S_SHIFT] = NILFS_FT_DIR, - [S_IFCHR >> S_SHIFT] = NILFS_FT_CHRDEV, - [S_IFBLK >> S_SHIFT] = NILFS_FT_BLKDEV, - [S_IFIFO >> S_SHIFT] = NILFS_FT_FIFO, - [S_IFSOCK >> S_SHIFT] = NILFS_FT_SOCK, - [S_IFLNK >> S_SHIFT] = NILFS_FT_SYMLINK, -}; - -static void nilfs_set_de_type(struct nilfs_dir_entry *de, struct inode *inode) -{ - umode_t mode = inode->i_mode; - - de->file_type = nilfs_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; -} - -static int nilfs_readdir(struct file *filp, void *dirent, filldir_t filldir) -{ - loff_t pos = filp->f_pos; - struct inode *inode = filp->f_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 = ~(nilfs_chunk_size(inode)-1); */ - unsigned char *types = NULL; - int ret; - - if (pos > inode->i_size - NILFS_DIR_REC_LEN(1)) - goto success; - - types = nilfs_filetype_table; - - for ( ; n < npages; n++, offset = 0) { - char *kaddr, *limit; - struct nilfs_dir_entry *de; - struct page *page = nilfs_get_page(inode, n); - - if (IS_ERR(page)) { - nilfs_error(sb, __func__, "bad page in #%lu", - inode->i_ino); - filp->f_pos += PAGE_CACHE_SIZE - offset; - ret = -EIO; - goto done; - } - kaddr = page_address(page); - de = (struct nilfs_dir_entry *)(kaddr + offset); - limit = kaddr + nilfs_last_byte(inode, n) - - NILFS_DIR_REC_LEN(1); - for ( ; (char *)de <= limit; de = nilfs_next_entry(de)) { - if (de->rec_len == 0) { - nilfs_error(sb, __func__, - "zero-length directory entry"); - ret = -EIO; - nilfs_put_page(page); - goto done; - } - if (de->inode) { - int over; - unsigned char d_type = DT_UNKNOWN; - - if (types && de->file_type < NILFS_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, - le64_to_cpu(de->inode), d_type); - if (over) { - nilfs_put_page(page); - goto success; - } - } - filp->f_pos += nilfs_rec_len_from_disk(de->rec_len); - } - nilfs_put_page(page); - } - -success: - ret = 0; -done: - return ret; -} - -/* - * nilfs_find_entry() - * - * finds an entry in the specified directory with the wanted name. It - * returns the page in which the entry was found, and the entry itself - * (as a parameter - res_dir). Page is returned mapped and unlocked. - * Entry is guaranteed to be valid. - */ -struct nilfs_dir_entry * -nilfs_find_entry(struct inode *dir, const struct qstr *qstr, - struct page **res_page) -{ - const unsigned char *name = qstr->name; - int namelen = qstr->len; - unsigned reclen = NILFS_DIR_REC_LEN(namelen); - unsigned long start, n; - unsigned long npages = dir_pages(dir); - struct page *page = NULL; - struct nilfs_inode_info *ei = NILFS_I(dir); - struct nilfs_dir_entry *de; - - 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 = nilfs_get_page(dir, n); - if (!IS_ERR(page)) { - kaddr = page_address(page); - de = (struct nilfs_dir_entry *)kaddr; - kaddr += nilfs_last_byte(dir, n) - reclen; - while ((char *) de <= kaddr) { - if (de->rec_len == 0) { - nilfs_error(dir->i_sb, __func__, - "zero-length directory entry"); - nilfs_put_page(page); - goto out; - } - if (nilfs_match(namelen, name, de)) - goto found; - de = nilfs_next_entry(de); - } - nilfs_put_page(page); - } - if (++n >= npages) - n = 0; - /* next page is past the blocks we've got */ - if (unlikely(n > (dir->i_blocks >> (PAGE_CACHE_SHIFT - 9)))) { - nilfs_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 nilfs_dir_entry *nilfs_dotdot(struct inode *dir, struct page **p) -{ - struct page *page = nilfs_get_page(dir, 0); - struct nilfs_dir_entry *de = NULL; - - if (!IS_ERR(page)) { - de = nilfs_next_entry( - (struct nilfs_dir_entry *)page_address(page)); - *p = page; - } - return de; -} - -ino_t nilfs_inode_by_name(struct inode *dir, const struct qstr *qstr) -{ - ino_t res = 0; - struct nilfs_dir_entry *de; - struct page *page; - - de = nilfs_find_entry(dir, qstr, &page); - if (de) { - res = le64_to_cpu(de->inode); - kunmap(page); - page_cache_release(page); - } - return res; -} - -/* Releases the page */ -void nilfs_set_link(struct inode *dir, struct nilfs_dir_entry *de, - struct page *page, struct inode *inode) -{ - unsigned from = (char *) de - (char *) page_address(page); - unsigned to = from + nilfs_rec_len_from_disk(de->rec_len); - struct address_space *mapping = page->mapping; - int err; - - lock_page(page); - err = nilfs_prepare_chunk(page, from, to); - BUG_ON(err); - de->inode = cpu_to_le64(inode->i_ino); - nilfs_set_de_type(de, inode); - nilfs_commit_chunk(page, mapping, from, to); - nilfs_put_page(page); - dir->i_mtime = dir->i_ctime = CURRENT_TIME; -} - -/* - * Parent is locked. - */ -int nilfs_add_link(struct dentry *dentry, struct inode *inode) -{ - struct inode *dir = dentry->d_parent->d_inode; - const unsigned char *name = dentry->d_name.name; - int namelen = dentry->d_name.len; - unsigned chunk_size = nilfs_chunk_size(dir); - unsigned reclen = NILFS_DIR_REC_LEN(namelen); - unsigned short rec_len, name_len; - struct page *page = NULL; - struct nilfs_dir_entry *de; - unsigned long npages = dir_pages(dir); - unsigned long n; - char *kaddr; - unsigned from, to; - 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 = nilfs_get_page(dir, n); - err = PTR_ERR(page); - if (IS_ERR(page)) - goto out; - lock_page(page); - kaddr = page_address(page); - dir_end = kaddr + nilfs_last_byte(dir, n); - de = (struct nilfs_dir_entry *)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 = nilfs_rec_len_to_disk(chunk_size); - de->inode = 0; - goto got_it; - } - if (de->rec_len == 0) { - nilfs_error(dir->i_sb, __func__, - "zero-length directory entry"); - err = -EIO; - goto out_unlock; - } - err = -EEXIST; - if (nilfs_match(namelen, name, de)) - goto out_unlock; - name_len = NILFS_DIR_REC_LEN(de->name_len); - rec_len = nilfs_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 = (struct nilfs_dir_entry *)((char *)de + rec_len); - } - unlock_page(page); - nilfs_put_page(page); - } - BUG(); - return -EINVAL; - -got_it: - from = (char *)de - (char *)page_address(page); - to = from + rec_len; - err = nilfs_prepare_chunk(page, from, to); - if (err) - goto out_unlock; - if (de->inode) { - struct nilfs_dir_entry *de1; - - de1 = (struct nilfs_dir_entry *)((char *)de + name_len); - de1->rec_len = nilfs_rec_len_to_disk(rec_len - name_len); - de->rec_len = nilfs_rec_len_to_disk(name_len); - de = de1; - } - de->name_len = namelen; - memcpy(de->name, name, namelen); - de->inode = cpu_to_le64(inode->i_ino); - nilfs_set_de_type(de, inode); - nilfs_commit_chunk(page, page->mapping, from, to); - dir->i_mtime = dir->i_ctime = CURRENT_TIME; - nilfs_mark_inode_dirty(dir); - /* OFFSET_CACHE */ -out_put: - nilfs_put_page(page); -out: - return err; -out_unlock: - unlock_page(page); - goto out_put; -} - -/* - * nilfs_delete_entry deletes a directory entry by merging it with the - * previous entry. Page is up-to-date. Releases the page. - */ -int nilfs_delete_entry(struct nilfs_dir_entry *dir, struct page *page) -{ - struct address_space *mapping = page->mapping; - struct inode *inode = mapping->host; - char *kaddr = page_address(page); - unsigned from = ((char *)dir - kaddr) & ~(nilfs_chunk_size(inode) - 1); - unsigned to = ((char *)dir - kaddr) + - nilfs_rec_len_from_disk(dir->rec_len); - struct nilfs_dir_entry *pde = NULL; - struct nilfs_dir_entry *de = (struct nilfs_dir_entry *)(kaddr + from); - int err; - - while ((char *)de < (char *)dir) { - if (de->rec_len == 0) { - nilfs_error(inode->i_sb, __func__, - "zero-length directory entry"); - err = -EIO; - goto out; - } - pde = de; - de = nilfs_next_entry(de); - } - if (pde) - from = (char *)pde - (char *)page_address(page); - lock_page(page); - err = nilfs_prepare_chunk(page, from, to); - BUG_ON(err); - if (pde) - pde->rec_len = nilfs_rec_len_to_disk(to - from); - dir->inode = 0; - nilfs_commit_chunk(page, mapping, from, to); - inode->i_ctime = inode->i_mtime = CURRENT_TIME; -out: - nilfs_put_page(page); - return err; -} - -/* - * Set the first fragment of directory. - */ -int nilfs_make_empty(struct inode *inode, struct inode *parent) -{ - struct address_space *mapping = inode->i_mapping; - struct page *page = grab_cache_page(mapping, 0); - unsigned chunk_size = nilfs_chunk_size(inode); - struct nilfs_dir_entry *de; - int err; - void *kaddr; - - if (!page) - return -ENOMEM; - - err = nilfs_prepare_chunk(page, 0, chunk_size); - if (unlikely(err)) { - unlock_page(page); - goto fail; - } - kaddr = kmap_atomic(page); - memset(kaddr, 0, chunk_size); - de = (struct nilfs_dir_entry *)kaddr; - de->name_len = 1; - de->rec_len = nilfs_rec_len_to_disk(NILFS_DIR_REC_LEN(1)); - memcpy(de->name, ".\0\0", 4); - de->inode = cpu_to_le64(inode->i_ino); - nilfs_set_de_type(de, inode); - - de = (struct nilfs_dir_entry *)(kaddr + NILFS_DIR_REC_LEN(1)); - de->name_len = 2; - de->rec_len = nilfs_rec_len_to_disk(chunk_size - NILFS_DIR_REC_LEN(1)); - de->inode = cpu_to_le64(parent->i_ino); - memcpy(de->name, "..\0", 4); - nilfs_set_de_type(de, inode); - kunmap_atomic(kaddr); - nilfs_commit_chunk(page, mapping, 0, chunk_size); -fail: - page_cache_release(page); - return err; -} - -/* - * routine to check that the specified directory is empty (for rmdir) - */ -int nilfs_empty_dir(struct inode *inode) -{ - struct page *page = NULL; - unsigned long i, npages = dir_pages(inode); - - for (i = 0; i < npages; i++) { - char *kaddr; - struct nilfs_dir_entry *de; - - page = nilfs_get_page(inode, i); - if (IS_ERR(page)) - continue; - - kaddr = page_address(page); - de = (struct nilfs_dir_entry *)kaddr; - kaddr += nilfs_last_byte(inode, i) - NILFS_DIR_REC_LEN(1); - - while ((char *)de <= kaddr) { - if (de->rec_len == 0) { - nilfs_error(inode->i_sb, __func__, - "zero-length directory entry " - "(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_le64(inode->i_ino)) - goto not_empty; - } else if (de->name[1] != '.') - goto not_empty; - } - de = nilfs_next_entry(de); - } - nilfs_put_page(page); - } - return 1; - -not_empty: - nilfs_put_page(page); - return 0; -} - -const struct file_operations nilfs_dir_operations = { - .llseek = generic_file_llseek, - .read = generic_read_dir, - .readdir = nilfs_readdir, - .unlocked_ioctl = nilfs_ioctl, -#ifdef CONFIG_COMPAT - .compat_ioctl = nilfs_compat_ioctl, -#endif /* CONFIG_COMPAT */ - .fsync = nilfs_sync_file, - -}; |