diff options
Diffstat (limited to 'fs/exofs/dir.c')
-rw-r--r-- | fs/exofs/dir.c | 661 |
1 files changed, 0 insertions, 661 deletions
diff --git a/fs/exofs/dir.c b/fs/exofs/dir.c deleted file mode 100644 index f0138674c1ed..000000000000 --- a/fs/exofs/dir.c +++ /dev/null @@ -1,661 +0,0 @@ -/* - * Copyright (C) 2005, 2006 - * Avishay Traeger (avishay@gmail.com) - * Copyright (C) 2008, 2009 - * Boaz Harrosh <ooo@electrozaur.com> - * - * Copyrights for code taken from ext2: - * 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/inode.c - * Copyright (C) 1991, 1992 Linus Torvalds - * - * This file is part of exofs. - * - * exofs 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. Since it is based on ext2, and the only - * valid version of GPL for the Linux kernel is version 2, the only valid - * version of GPL for exofs is version 2. - * - * exofs 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 exofs; if not, write to the Free Software - * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA - */ - -#include <linux/iversion.h> -#include "exofs.h" - -static inline unsigned exofs_chunk_size(struct inode *inode) -{ - return inode->i_sb->s_blocksize; -} - -static inline void exofs_put_page(struct page *page) -{ - kunmap(page); - put_page(page); -} - -static unsigned exofs_last_byte(struct inode *inode, unsigned long page_nr) -{ - loff_t last_byte = inode->i_size; - - last_byte -= page_nr << PAGE_SHIFT; - if (last_byte > PAGE_SIZE) - last_byte = PAGE_SIZE; - return last_byte; -} - -static int exofs_commit_chunk(struct page *page, loff_t pos, unsigned len) -{ - struct address_space *mapping = page->mapping; - struct inode *dir = mapping->host; - int err = 0; - - inode_inc_iversion(dir); - - if (!PageUptodate(page)) - SetPageUptodate(page); - - if (pos+len > dir->i_size) { - i_size_write(dir, pos+len); - mark_inode_dirty(dir); - } - set_page_dirty(page); - - if (IS_DIRSYNC(dir)) - err = write_one_page(page); - else - unlock_page(page); - - return err; -} - -static bool exofs_check_page(struct page *page) -{ - struct inode *dir = page->mapping->host; - unsigned chunk_size = exofs_chunk_size(dir); - char *kaddr = page_address(page); - unsigned offs, rec_len; - unsigned limit = PAGE_SIZE; - struct exofs_dir_entry *p; - char *error; - - /* if the page is the last one in the directory */ - if ((dir->i_size >> PAGE_SHIFT) == page->index) { - limit = dir->i_size & ~PAGE_MASK; - if (limit & (chunk_size - 1)) - goto Ebadsize; - if (!limit) - goto out; - } - for (offs = 0; offs <= limit - EXOFS_DIR_REC_LEN(1); offs += rec_len) { - p = (struct exofs_dir_entry *)(kaddr + offs); - rec_len = le16_to_cpu(p->rec_len); - - if (rec_len < EXOFS_DIR_REC_LEN(1)) - goto Eshort; - if (rec_len & 3) - goto Ealign; - if (rec_len < EXOFS_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 true; - -Ebadsize: - EXOFS_ERR("ERROR [exofs_check_page]: " - "size of directory(0x%lx) is not a multiple of chunk size\n", - 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; -bad_entry: - EXOFS_ERR( - "ERROR [exofs_check_page]: bad entry in directory(0x%lx): %s - " - "offset=%lu, inode=0x%llx, rec_len=%d, name_len=%d\n", - dir->i_ino, error, (page->index<<PAGE_SHIFT)+offs, - _LLU(le64_to_cpu(p->inode_no)), - rec_len, p->name_len); - goto fail; -Eend: - p = (struct exofs_dir_entry *)(kaddr + offs); - EXOFS_ERR("ERROR [exofs_check_page]: " - "entry in directory(0x%lx) spans the page boundary" - "offset=%lu, inode=0x%llx\n", - dir->i_ino, (page->index<<PAGE_SHIFT)+offs, - _LLU(le64_to_cpu(p->inode_no))); -fail: - SetPageError(page); - return false; -} - -static struct page *exofs_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 (unlikely(!PageChecked(page))) { - if (PageError(page) || !exofs_check_page(page)) - goto fail; - } - } - return page; - -fail: - exofs_put_page(page); - return ERR_PTR(-EIO); -} - -static inline int exofs_match(int len, const unsigned char *name, - struct exofs_dir_entry *de) -{ - if (len != de->name_len) - return 0; - if (!de->inode_no) - return 0; - return !memcmp(name, de->name, len); -} - -static inline -struct exofs_dir_entry *exofs_next_entry(struct exofs_dir_entry *p) -{ - return (struct exofs_dir_entry *)((char *)p + le16_to_cpu(p->rec_len)); -} - -static inline unsigned -exofs_validate_entry(char *base, unsigned offset, unsigned mask) -{ - struct exofs_dir_entry *de = (struct exofs_dir_entry *)(base + offset); - struct exofs_dir_entry *p = - (struct exofs_dir_entry *)(base + (offset&mask)); - while ((char *)p < (char *)de) { - if (p->rec_len == 0) - break; - p = exofs_next_entry(p); - } - return (char *)p - base; -} - -static unsigned char exofs_filetype_table[EXOFS_FT_MAX] = { - [EXOFS_FT_UNKNOWN] = DT_UNKNOWN, - [EXOFS_FT_REG_FILE] = DT_REG, - [EXOFS_FT_DIR] = DT_DIR, - [EXOFS_FT_CHRDEV] = DT_CHR, - [EXOFS_FT_BLKDEV] = DT_BLK, - [EXOFS_FT_FIFO] = DT_FIFO, - [EXOFS_FT_SOCK] = DT_SOCK, - [EXOFS_FT_SYMLINK] = DT_LNK, -}; - -#define S_SHIFT 12 -static unsigned char exofs_type_by_mode[S_IFMT >> S_SHIFT] = { - [S_IFREG >> S_SHIFT] = EXOFS_FT_REG_FILE, - [S_IFDIR >> S_SHIFT] = EXOFS_FT_DIR, - [S_IFCHR >> S_SHIFT] = EXOFS_FT_CHRDEV, - [S_IFBLK >> S_SHIFT] = EXOFS_FT_BLKDEV, - [S_IFIFO >> S_SHIFT] = EXOFS_FT_FIFO, - [S_IFSOCK >> S_SHIFT] = EXOFS_FT_SOCK, - [S_IFLNK >> S_SHIFT] = EXOFS_FT_SYMLINK, -}; - -static inline -void exofs_set_de_type(struct exofs_dir_entry *de, struct inode *inode) -{ - umode_t mode = inode->i_mode; - de->file_type = exofs_type_by_mode[(mode & S_IFMT) >> S_SHIFT]; -} - -static int -exofs_readdir(struct file *file, struct dir_context *ctx) -{ - loff_t pos = ctx->pos; - struct inode *inode = file_inode(file); - unsigned int offset = pos & ~PAGE_MASK; - unsigned long n = pos >> PAGE_SHIFT; - unsigned long npages = dir_pages(inode); - unsigned chunk_mask = ~(exofs_chunk_size(inode)-1); - bool need_revalidate = !inode_eq_iversion(inode, file->f_version); - - if (pos > inode->i_size - EXOFS_DIR_REC_LEN(1)) - return 0; - - for ( ; n < npages; n++, offset = 0) { - char *kaddr, *limit; - struct exofs_dir_entry *de; - struct page *page = exofs_get_page(inode, n); - - if (IS_ERR(page)) { - EXOFS_ERR("ERROR: bad page in directory(0x%lx)\n", - inode->i_ino); - ctx->pos += PAGE_SIZE - offset; - return PTR_ERR(page); - } - kaddr = page_address(page); - if (unlikely(need_revalidate)) { - if (offset) { - offset = exofs_validate_entry(kaddr, offset, - chunk_mask); - ctx->pos = (n<<PAGE_SHIFT) + offset; - } - file->f_version = inode_query_iversion(inode); - need_revalidate = false; - } - de = (struct exofs_dir_entry *)(kaddr + offset); - limit = kaddr + exofs_last_byte(inode, n) - - EXOFS_DIR_REC_LEN(1); - for (; (char *)de <= limit; de = exofs_next_entry(de)) { - if (de->rec_len == 0) { - EXOFS_ERR("ERROR: " - "zero-length entry in directory(0x%lx)\n", - inode->i_ino); - exofs_put_page(page); - return -EIO; - } - if (de->inode_no) { - unsigned char t; - - if (de->file_type < EXOFS_FT_MAX) - t = exofs_filetype_table[de->file_type]; - else - t = DT_UNKNOWN; - - if (!dir_emit(ctx, de->name, de->name_len, - le64_to_cpu(de->inode_no), - t)) { - exofs_put_page(page); - return 0; - } - } - ctx->pos += le16_to_cpu(de->rec_len); - } - exofs_put_page(page); - } - return 0; -} - -struct exofs_dir_entry *exofs_find_entry(struct inode *dir, - struct dentry *dentry, struct page **res_page) -{ - const unsigned char *name = dentry->d_name.name; - int namelen = dentry->d_name.len; - unsigned reclen = EXOFS_DIR_REC_LEN(namelen); - unsigned long start, n; - unsigned long npages = dir_pages(dir); - struct page *page = NULL; - struct exofs_i_info *oi = exofs_i(dir); - struct exofs_dir_entry *de; - - if (npages == 0) - goto out; - - *res_page = NULL; - - start = oi->i_dir_start_lookup; - if (start >= npages) - start = 0; - n = start; - do { - char *kaddr; - page = exofs_get_page(dir, n); - if (!IS_ERR(page)) { - kaddr = page_address(page); - de = (struct exofs_dir_entry *) kaddr; - kaddr += exofs_last_byte(dir, n) - reclen; - while ((char *) de <= kaddr) { - if (de->rec_len == 0) { - EXOFS_ERR("ERROR: zero-length entry in " - "directory(0x%lx)\n", - dir->i_ino); - exofs_put_page(page); - goto out; - } - if (exofs_match(namelen, name, de)) - goto found; - de = exofs_next_entry(de); - } - exofs_put_page(page); - } - if (++n >= npages) - n = 0; - } while (n != start); -out: - return NULL; - -found: - *res_page = page; - oi->i_dir_start_lookup = n; - return de; -} - -struct exofs_dir_entry *exofs_dotdot(struct inode *dir, struct page **p) -{ - struct page *page = exofs_get_page(dir, 0); - struct exofs_dir_entry *de = NULL; - - if (!IS_ERR(page)) { - de = exofs_next_entry( - (struct exofs_dir_entry *)page_address(page)); - *p = page; - } - return de; -} - -ino_t exofs_parent_ino(struct dentry *child) -{ - struct page *page; - struct exofs_dir_entry *de; - ino_t ino; - - de = exofs_dotdot(d_inode(child), &page); - if (!de) - return 0; - - ino = le64_to_cpu(de->inode_no); - exofs_put_page(page); - return ino; -} - -ino_t exofs_inode_by_name(struct inode *dir, struct dentry *dentry) -{ - ino_t res = 0; - struct exofs_dir_entry *de; - struct page *page; - - de = exofs_find_entry(dir, dentry, &page); - if (de) { - res = le64_to_cpu(de->inode_no); - exofs_put_page(page); - } - return res; -} - -int exofs_set_link(struct inode *dir, struct exofs_dir_entry *de, - struct page *page, struct inode *inode) -{ - loff_t pos = page_offset(page) + - (char *) de - (char *) page_address(page); - unsigned len = le16_to_cpu(de->rec_len); - int err; - - lock_page(page); - err = exofs_write_begin(NULL, page->mapping, pos, len, 0, &page, NULL); - if (err) - EXOFS_ERR("exofs_set_link: exofs_write_begin FAILED => %d\n", - err); - - de->inode_no = cpu_to_le64(inode->i_ino); - exofs_set_de_type(de, inode); - if (likely(!err)) - err = exofs_commit_chunk(page, pos, len); - exofs_put_page(page); - dir->i_mtime = dir->i_ctime = current_time(dir); - mark_inode_dirty(dir); - return err; -} - -int exofs_add_link(struct dentry *dentry, struct inode *inode) -{ - struct inode *dir = d_inode(dentry->d_parent); - const unsigned char *name = dentry->d_name.name; - int namelen = dentry->d_name.len; - unsigned chunk_size = exofs_chunk_size(dir); - unsigned reclen = EXOFS_DIR_REC_LEN(namelen); - unsigned short rec_len, name_len; - struct page *page = NULL; - struct exofs_sb_info *sbi = inode->i_sb->s_fs_info; - struct exofs_dir_entry *de; - unsigned long npages = dir_pages(dir); - unsigned long n; - char *kaddr; - loff_t pos; - int err; - - for (n = 0; n <= npages; n++) { - char *dir_end; - - page = exofs_get_page(dir, n); - err = PTR_ERR(page); - if (IS_ERR(page)) - goto out; - lock_page(page); - kaddr = page_address(page); - dir_end = kaddr + exofs_last_byte(dir, n); - de = (struct exofs_dir_entry *)kaddr; - kaddr += PAGE_SIZE - reclen; - while ((char *)de <= kaddr) { - if ((char *)de == dir_end) { - name_len = 0; - rec_len = chunk_size; - de->rec_len = cpu_to_le16(chunk_size); - de->inode_no = 0; - goto got_it; - } - if (de->rec_len == 0) { - EXOFS_ERR("ERROR: exofs_add_link: " - "zero-length entry in directory(0x%lx)\n", - inode->i_ino); - err = -EIO; - goto out_unlock; - } - err = -EEXIST; - if (exofs_match(namelen, name, de)) - goto out_unlock; - name_len = EXOFS_DIR_REC_LEN(de->name_len); - rec_len = le16_to_cpu(de->rec_len); - if (!de->inode_no && rec_len >= reclen) - goto got_it; - if (rec_len >= name_len + reclen) - goto got_it; - de = (struct exofs_dir_entry *) ((char *) de + rec_len); - } - unlock_page(page); - exofs_put_page(page); - } - - EXOFS_ERR("exofs_add_link: BAD dentry=%p or inode=0x%lx\n", - dentry, inode->i_ino); - return -EINVAL; - -got_it: - pos = page_offset(page) + - (char *)de - (char *)page_address(page); - err = exofs_write_begin(NULL, page->mapping, pos, rec_len, 0, - &page, NULL); - if (err) - goto out_unlock; - if (de->inode_no) { - struct exofs_dir_entry *de1 = - (struct exofs_dir_entry *)((char *)de + name_len); - de1->rec_len = cpu_to_le16(rec_len - name_len); - de->rec_len = cpu_to_le16(name_len); - de = de1; - } - de->name_len = namelen; - memcpy(de->name, name, namelen); - de->inode_no = cpu_to_le64(inode->i_ino); - exofs_set_de_type(de, inode); - err = exofs_commit_chunk(page, pos, rec_len); - dir->i_mtime = dir->i_ctime = current_time(dir); - mark_inode_dirty(dir); - sbi->s_numfiles++; - -out_put: - exofs_put_page(page); -out: - return err; -out_unlock: - unlock_page(page); - goto out_put; -} - -int exofs_delete_entry(struct exofs_dir_entry *dir, struct page *page) -{ - struct address_space *mapping = page->mapping; - struct inode *inode = mapping->host; - struct exofs_sb_info *sbi = inode->i_sb->s_fs_info; - char *kaddr = page_address(page); - unsigned from = ((char *)dir - kaddr) & ~(exofs_chunk_size(inode)-1); - unsigned to = ((char *)dir - kaddr) + le16_to_cpu(dir->rec_len); - loff_t pos; - struct exofs_dir_entry *pde = NULL; - struct exofs_dir_entry *de = (struct exofs_dir_entry *) (kaddr + from); - int err; - - while (de < dir) { - if (de->rec_len == 0) { - EXOFS_ERR("ERROR: exofs_delete_entry:" - "zero-length entry in directory(0x%lx)\n", - inode->i_ino); - err = -EIO; - goto out; - } - pde = de; - de = exofs_next_entry(de); - } - if (pde) - from = (char *)pde - (char *)page_address(page); - pos = page_offset(page) + from; - lock_page(page); - err = exofs_write_begin(NULL, page->mapping, pos, to - from, 0, - &page, NULL); - if (err) - EXOFS_ERR("exofs_delete_entry: exofs_write_begin FAILED => %d\n", - err); - if (pde) - pde->rec_len = cpu_to_le16(to - from); - dir->inode_no = 0; - if (likely(!err)) - err = exofs_commit_chunk(page, pos, to - from); - inode->i_ctime = inode->i_mtime = current_time(inode); - mark_inode_dirty(inode); - sbi->s_numfiles--; -out: - exofs_put_page(page); - return err; -} - -/* kept aligned on 4 bytes */ -#define THIS_DIR ".\0\0" -#define PARENT_DIR "..\0" - -int exofs_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 = exofs_chunk_size(inode); - struct exofs_dir_entry *de; - int err; - void *kaddr; - - if (!page) - return -ENOMEM; - - err = exofs_write_begin(NULL, page->mapping, 0, chunk_size, 0, - &page, NULL); - if (err) { - unlock_page(page); - goto fail; - } - - kaddr = kmap_atomic(page); - de = (struct exofs_dir_entry *)kaddr; - de->name_len = 1; - de->rec_len = cpu_to_le16(EXOFS_DIR_REC_LEN(1)); - memcpy(de->name, THIS_DIR, sizeof(THIS_DIR)); - de->inode_no = cpu_to_le64(inode->i_ino); - exofs_set_de_type(de, inode); - - de = (struct exofs_dir_entry *)(kaddr + EXOFS_DIR_REC_LEN(1)); - de->name_len = 2; - de->rec_len = cpu_to_le16(chunk_size - EXOFS_DIR_REC_LEN(1)); - de->inode_no = cpu_to_le64(parent->i_ino); - memcpy(de->name, PARENT_DIR, sizeof(PARENT_DIR)); - exofs_set_de_type(de, inode); - kunmap_atomic(kaddr); - err = exofs_commit_chunk(page, 0, chunk_size); -fail: - put_page(page); - return err; -} - -int exofs_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 exofs_dir_entry *de; - page = exofs_get_page(inode, i); - - if (IS_ERR(page)) - continue; - - kaddr = page_address(page); - de = (struct exofs_dir_entry *)kaddr; - kaddr += exofs_last_byte(inode, i) - EXOFS_DIR_REC_LEN(1); - - while ((char *)de <= kaddr) { - if (de->rec_len == 0) { - EXOFS_ERR("ERROR: exofs_empty_dir: " - "zero-length directory entry" - "kaddr=%p, de=%p\n", kaddr, de); - goto not_empty; - } - if (de->inode_no != 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 (le64_to_cpu(de->inode_no) != - inode->i_ino) - goto not_empty; - } else if (de->name[1] != '.') - goto not_empty; - } - de = exofs_next_entry(de); - } - exofs_put_page(page); - } - return 1; - -not_empty: - exofs_put_page(page); - return 0; -} - -const struct file_operations exofs_dir_operations = { - .llseek = generic_file_llseek, - .read = generic_read_dir, - .iterate_shared = exofs_readdir, -}; |