/*
* linux/fs/ext2/dir.c
*
- * This code is issued under the GNU General Public License.
- * See the file COPYING in this distribution
- *
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Big-endian to little-endian byte-swapping/bitmaps by
* David S. Miller (davem@caip.rutgers.edu), 1995
*
- * Changes for use with Object Based Device File System
- *
- * Copyright (C) 1999, Seagate Technology Inc.
- * (author Peter J. Braam, braam@stelias.com)
- *
+ * All code that works with directory layout had been switched to pagecache
+ * and moved here. AV
*/
-#include <asm/uaccess.h>
-
-#include <linux/errno.h>
#include <linux/fs.h>
-#include <linux/fcntl.h>
-#include <linux/sched.h>
-#include <linux/stat.h>
-#include <linux/string.h>
-#include <linux/locks.h>
-#include <linux/quotaops.h>
-#include <linux/iobuf.h>
+#include <linux/ext2_fs.h>
+#include <linux/pagemap.h>
#include <linux/obd_support.h>
-#include <linux/obdfs.h>
+#include <linux/locks.h>
-static ssize_t obdfs_dir_read (struct file * filp, char * buf,
- size_t count, loff_t *ppos)
+typedef struct ext2_dir_entry_2 ext2_dirent;
+
+#define PageChecked(page) test_bit(PG_checked, &(page)->flags)
+#define SetPageChecked(page) set_bit(PG_checked, &(page)->flags)
+#define PG_checked 13 /* kill me in 2.5.<early>. */
+
+int waitfor_one_page(struct page *page)
{
- return -EISDIR;
+ int error = 0;
+ struct buffer_head *bh, *head = page->buffers;
+
+ bh = head;
+ do {
+ wait_on_buffer(bh);
+ if (buffer_req(bh) && !buffer_uptodate(bh))
+ error = -EIO;
+ } while ((bh = bh->b_this_page) != head);
+ return error;
}
-static int obdfs_readdir(struct file *, void *, filldir_t);
-extern int new_obdfs_readdir(struct file *, void *, filldir_t);
+/*
+ * 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;
+ return PAGE_SIZE;
+}
-struct file_operations obdfs_dir_operations = {
- read: obdfs_dir_read,
- readdir: new_obdfs_readdir
+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;
+}
+
+static int ext2_commit_chunk(struct page *page, unsigned from, unsigned to)
+{
+ struct inode *dir = page->mapping->host;
+ int err = 0;
+ dir->i_version = ++event;
+ page->mapping->a_ops->commit_write(NULL, page, from, to);
+ if (IS_SYNC(dir))
+ err = waitfor_one_page(page);
+ return err;
+}
+
+static void ext2_check_page(struct page *page)
+{
+ 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(sb->u.ext2_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;
+ for (offs = limit; offs<PAGE_CACHE_SIZE; offs += chunk_size) {
+ ext2_dirent *p = (ext2_dirent*)(kaddr + offs);
+ p->rec_len = cpu_to_le16(chunk_size);
+ }
+ if (!limit)
+ goto out;
+ }
+ for (offs = 0; offs <= limit - EXT2_DIR_REC_LEN(1); offs += rec_len) {
+ p = (ext2_dirent *)(kaddr + offs);
+ rec_len = le16_to_cpu(p->rec_len);
+
+ if (rec_len < EXT2_DIR_REC_LEN(1))
+ goto Eshort;
+ if (rec_len & 3)
+ goto Ealign;
+ if (rec_len < EXT2_DIR_REC_LEN(p->name_len))
+ goto Enamelen;
+ if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1))
+ goto Espan;
+ // if (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:
+ ext2_error(sb, "ext2_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";
+ goto bad_entry;
+ //Einumber:
+ // error = "inode out of bounds";
+bad_entry:
+ ext2_error (sb, "ext2_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) le32_to_cpu(p->inode),
+ rec_len, p->name_len);
+ goto fail;
+Eend:
+ 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)
+{
+ struct address_space *mapping = dir->i_mapping;
+ struct page *page = read_cache_page(mapping, n,
+ (filler_t*)mapping->a_ops->readpage, NULL);
+ if (!IS_ERR(page)) {
+ wait_on_page(page);
+ kmap(page);
+ if (!Page_Uptodate(page))
+ goto fail;
+ if (!PageChecked(page))
+ ext2_check_page(page);
+ 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 + le16_to_cpu(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)
+ 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,
};
-extern struct dentry *new_obdfs_lookup(struct inode * dir, struct dentry *dentry);
-struct inode_operations obdfs_dir_inode_operations = {
- create: obdfs_create,
- lookup: new_obdfs_lookup,
- link: obdfs_link,
- unlink: obdfs_unlink,
- symlink: obdfs_symlink,
- mkdir: obdfs_mkdir,
- rmdir: obdfs_rmdir,
- mknod: obdfs_mknod,
- rename: obdfs_rename,
- truncate: obdfs_truncate
+#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,
};
-int obdfs_check_dir_entry (const char * function, struct inode * dir,
- struct ext2_dir_entry_2 * de,
- struct page * page,
- unsigned long offset)
-{
- const char * error_msg = NULL;
- return 1;
-
- ENTRY;
- if ( !de ) {
- error_msg = "null de passed";
- return 1;
- }
-
- if (le16_to_cpu(de->rec_len) < EXT2_DIR_REC_LEN(1))
- error_msg = "rec_len is smaller than minimal";
- else if (le16_to_cpu(de->rec_len) % 4 != 0)
- error_msg = "rec_len % 4 != 0";
- else if (le16_to_cpu(de->rec_len) < EXT2_DIR_REC_LEN(de->name_len))
- error_msg = "rec_len is too small for name_len";
- else if (dir && ((char *) de - (char *)page_address(page)) + le16_to_cpu(de->rec_len) >
- dir->i_sb->s_blocksize)
- error_msg = "directory entry across blocks";
-#if 0 /* this one doesn't yet work for OBDFS */
- else
-
-if (dir && le32_to_cpu(de->inode) > le32_to_cpu(dir->i_sb->u.ext2_sb.s_es->s_inodes_count))
- error_msg = "inode out of bounds";
-#endif
- if (error_msg != NULL)
- ext2_error (dir->i_sb, function, "bad entry in directory #%lu: %s - "
- "offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
- dir->i_ino, error_msg, offset,
- (unsigned long) le32_to_cpu(de->inode),
- le16_to_cpu(de->rec_len), de->name_len);
- EXIT;
- return error_msg == NULL ? 1 : 0;
-}
-
-
-static int obdfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
-{
- int error = 0;
- unsigned long offset;
- int stored;
- struct ext2_dir_entry_2 * de;
- struct super_block * sb;
- struct page *page;
- struct inode *inode = filp->f_dentry->d_inode;
-
- ENTRY;
-
- sb = inode->i_sb;
-
- stored = 0;
- offset = filp->f_pos & (PAGE_SIZE - 1);
-
- OIDEBUG(inode);
- while (!error && !stored && filp->f_pos < inode->i_size) {
- page = obdfs_getpage(inode, filp->f_pos, 0, LOCKED);
- /* PDEBUG(page, "readdir"); */
- if (!page) {
- ext2_error (sb, "ext2_readdir",
- "directory #%lu contains a hole at offset %lu",
- inode->i_ino, (unsigned long)filp->f_pos);
- filp->f_pos += PAGE_SIZE - offset;
- continue;
- }
-
-#if 0
- /* XXX need to do read ahead and support stuff below */
-revalidate:
- /* If the dir block has changed since the last call to
- * readdir(2), then we might be pointing to an invalid
- * dirent right now. Scan from the start of the block
- * to make sure. */
- if (filp->f_version != inode->i_version) {
- for (i = 0; i < sb->s_blocksize && i < offset; ) {
- de = (struct ext2_dir_entry_2 *)
- (bh->b_data + i);
- /* It's too expensive to do a full
- * dirent test each time round this
- * loop, but we do have to test at
- * least that it is non-zero. A
- * failure will be detected in the
- * dirent test below. */
- if (le16_to_cpu(de->rec_len) < EXT2_DIR_REC_LEN(1))
- break;
- i += le16_to_cpu(de->rec_len);
- }
- offset = i;
- filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
- | offset;
- filp->f_version = inode->i_version;
- }
-#endif
- while (!error && filp->f_pos < inode->i_size
- && offset < PAGE_SIZE) {
- de = (struct ext2_dir_entry_2 *) ((char *)page_address(page) + offset);
-#if 0
- if (!obdfs_check_dir_entry ("ext2_readdir", inode, de,
- bh, offset)) {
- /* On error, skip the f_pos to the
- next block. */
- filp->f_pos = (filp->f_pos & (sb->s_blocksize - 1))
- + sb->s_blocksize;
- brelse (bh);
- return stored;
- }
-#endif
- offset += le16_to_cpu(de->rec_len);
- if (le32_to_cpu(de->inode)) {
- unsigned char d_type = DT_UNKNOWN;
- /* We might block in the next section
- * if the data destination is
- * currently swapped out. So, use a
- * version stamp to detect whether or
- * not the directory has been modified
- * during the copy operation.
- */
- /* XXX
- unsigned long version = inode->i_version;
- */
- error = filldir
- (dirent, de->name, de->name_len,
- filp->f_pos, le32_to_cpu(de->inode),
- d_type);
- if (error)
- break;
-#if 0
- if (version != inode->i_version)
- goto revalidate;
-#endif
- stored ++;
- }
- filp->f_pos += le16_to_cpu(de->rec_len);
- }
- offset = 0;
- obd_unlock_page(page);
- page_cache_release(page);
- }
- UPDATE_ATIME(inode);
- EXIT;
- return 0;
+static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode)
+{
+ /* XXX
+ mode_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;
+ */
+ de->file_type = 0;
+}
+
+int
+new_obdfs_readdir (struct file * filp, void * dirent, filldir_t filldir)
+{
+ loff_t pos = filp->f_pos;
+ struct inode *inode = filp->f_dentry->d_inode;
+ // XXX struct super_block *sb = inode->i_sb;
+ unsigned 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))
+ goto done;
+
+ //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);
+
+ if (IS_ERR(page))
+ continue;
+ kaddr = page_address(page);
+ if (need_revalidate) {
+ offset = ext2_validate_entry(kaddr, offset, chunk_mask);
+ need_revalidate = 0;
+ }
+ de = (ext2_dirent *)(kaddr+offset);
+ limit = kaddr + PAGE_CACHE_SIZE - EXT2_DIR_REC_LEN(1);
+ for ( ;(char*)de <= limit; de = ext2_next_entry(de))
+ 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);
+ goto done;
+ }
+ }
+ ext2_put_page(page);
+ }
+
+done:
+ filp->f_pos = (n << PAGE_CACHE_SHIFT) | offset;
+ filp->f_version = inode->i_version;
+ UPDATE_ATIME(inode);
+ 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, and the entry itself
+ * (as a parameter - res_dir). Page is returned mapped and unlocked.
+ * Entry is guaranteed to be valid.
+ */
+struct ext2_dir_entry_2 * ext2_find_entry (struct inode * dir,
+ struct dentry *dentry, struct page ** res_page)
+{
+ const char *name = dentry->d_name.name;
+ int namelen = dentry->d_name.len;
+ unsigned reclen = EXT2_DIR_REC_LEN(namelen);
+ unsigned long start, n;
+ unsigned long npages = dir_pages(dir);
+ struct page *page = NULL;
+ ext2_dirent * de;
+
+ /* OFFSET_CACHE */
+ *res_page = NULL;
+
+ // start = dir->u.ext2_i.i_dir_start_lookup;
+ start = 0;
+ if (start >= npages)
+ start = 0;
+ n = start;
+ do {
+ char *kaddr;
+ page = ext2_get_page(dir, n);
+ if (!IS_ERR(page)) {
+ kaddr = page_address(page);
+ de = (ext2_dirent *) kaddr;
+ kaddr += PAGE_CACHE_SIZE - reclen;
+ while ((char *) de <= kaddr) {
+ if (ext2_match (namelen, name, de))
+ goto found;
+ de = ext2_next_entry(de);
+ }
+ ext2_put_page(page);
+ }
+ if (++n >= npages)
+ n = 0;
+ } while (n != start);
+ return NULL;
+
+found:
+ *res_page = page;
+ // dir->u.ext2_i.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);
+ 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 dentry *dentry)
+{
+ ino_t res = 0;
+ struct ext2_dir_entry_2 * de;
+ struct page *page;
+
+ de = ext2_find_entry (dir, dentry, &page);
+ if (de) {
+ res = le32_to_cpu(de->inode);
+ kunmap(page);
+ page_cache_release(page);
+ }
+ return res;
+}
+
+/* Releases the page */
+void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
+ struct page *page, struct inode *inode)
+{
+ unsigned from = (char *) de - (char *) page_address(page);
+ unsigned to = from + le16_to_cpu(de->rec_len);
+ int err;
+
+ lock_page(page);
+ err = page->mapping->a_ops->prepare_write(NULL, page, from, to);
+ if (err)
+ BUG();
+ de->inode = cpu_to_le32(inode->i_ino);
+ ext2_set_de_type (de, inode);
+ err = ext2_commit_chunk(page, from, to);
+ UnlockPage(page);
+ ext2_put_page(page);
+ dir->i_mtime = dir->i_ctime = CURRENT_TIME;
+ 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 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;
+ unsigned from, to;
+ int err;
+
+ /* We take care of directory expansion in the same loop */
+ for (n = 0; n <= npages; n++) {
+ page = ext2_get_page(dir, n);
+ err = PTR_ERR(page);
+ if (IS_ERR(page))
+ goto out;
+ kaddr = page_address(page);
+ de = (ext2_dirent *)kaddr;
+ kaddr += PAGE_CACHE_SIZE - reclen;
+ while ((char *)de <= kaddr) {
+ err = -EEXIST;
+ if (ext2_match (namelen, name, de))
+ goto out_page;
+ name_len = EXT2_DIR_REC_LEN(de->name_len);
+ rec_len = le16_to_cpu(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);
+ }
+ ext2_put_page(page);
+ }
+ BUG();
+ return -EINVAL;
+
+got_it:
+ from = (char*)de - (char*)page_address(page);
+ to = from + rec_len;
+ lock_page(page);
+ err = page->mapping->a_ops->prepare_write(NULL, page, from, to);
+ if (err)
+ goto out_unlock;
+ if (de->inode) {
+ ext2_dirent *de1 = (ext2_dirent *) ((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 = cpu_to_le32(inode->i_ino);
+ ext2_set_de_type (de, inode);
+ err = ext2_commit_chunk(page, from, to);
+ dir->i_mtime = dir->i_ctime = CURRENT_TIME;
+ mark_inode_dirty(dir);
+ /* OFFSET_CACHE */
+out_unlock:
+ UnlockPage(page);
+out_page:
+ ext2_put_page(page);
+out:
+ return err;
+}
+
+/*
+ * 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 address_space *mapping = page->mapping;
+ struct inode *inode = mapping->host;
+ char *kaddr = page_address(page);
+ unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1);
+ unsigned to = ((char*)dir - kaddr) + le16_to_cpu(dir->rec_len);
+ ext2_dirent * pde = NULL;
+ ext2_dirent * de = (ext2_dirent *) (kaddr + from);
+ int err;
+
+ while ((char*)de < (char*)dir) {
+ pde = de;
+ de = ext2_next_entry(de);
+ }
+ if (pde)
+ from = (char*)pde - (char*)page_address(page);
+ lock_page(page);
+ err = mapping->a_ops->prepare_write(NULL, page, from, to);
+ if (err)
+ BUG();
+ if (pde)
+ pde->rec_len = cpu_to_le16(to-from);
+ dir->inode = 0;
+ err = ext2_commit_chunk(page, from, to);
+ UnlockPage(page);
+ ext2_put_page(page);
+ inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+ mark_inode_dirty(inode);
+ return err;
+}
+
+/*
+ * Set the first fragment of directory.
+ */
+int ext2_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 = ext2_chunk_size(inode);
+ struct ext2_dir_entry_2 * de;
+ char *base;
+ int err;
+
+ if (!page)
+ return -ENOMEM;
+ err = mapping->a_ops->prepare_write(NULL, page, 0, chunk_size);
+ if (err)
+ goto fail;
+
+ base = page_address(page);
+
+ de = (struct ext2_dir_entry_2 *) base;
+ de->name_len = 1;
+ de->rec_len = cpu_to_le16(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 *) (base + EXT2_DIR_REC_LEN(1));
+ de->name_len = 2;
+ de->rec_len = cpu_to_le16(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);
+
+ err = ext2_commit_chunk(page, 0, chunk_size);
+fail:
+ UnlockPage(page);
+ 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);
+
+ for (i = 0; i < npages; i++) {
+ char *kaddr;
+ ext2_dirent * de;
+ page = ext2_get_page(inode, i);
+
+ if (IS_ERR(page))
+ continue;
+
+ kaddr = page_address(page);
+ de = (ext2_dirent *)kaddr;
+ kaddr += PAGE_CACHE_SIZE-EXT2_DIR_REC_LEN(1);
+
+ while ((char *)de <= kaddr) {
+ 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;
+}
+
+struct file_operations obdfs_dir_operations = {
+ read: generic_read_dir,
+ readdir: new_obdfs_readdir
+};
git://git.whamcloud.com / fs / lustre-release.git / blobdiff