1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
11 * linux/fs/minix/dir.c
14 * Copyright (C) 1991, 1992 Linus Torvalds
16 * ext2 directory handling functions
18 * Big-endian to little-endian byte-swapping/bitmaps by
19 * David S. Miller (davem@caip.rutgers.edu), 1995
21 * All code that works with directory layout had been switched to pagecache
24 * Adapted for Lustre Light
25 * Copyright (C) 2002, Cluster File Systems, Inc.
30 #include <linux/ext2_fs.h>
31 #include <linux/pagemap.h>
33 #include <linux/locks.h>
34 #include <asm/uaccess.h>
36 #define DEBUG_SUBSYSTEM S_LLITE
38 #include <linux/obd_support.h>
39 #include <linux/obd_class.h>
40 #include <linux/lustre_lib.h>
41 #include <linux/lustre_idl.h>
42 #include <linux/lustre_mds.h>
43 #include <linux/lustre_lite.h>
44 #include <linux/lustre_dlm.h>
46 typedef struct ext2_dir_entry_2 ext2_dirent;
48 #define PageChecked(page) test_bit(PG_checked, &(page)->flags)
49 #define SetPageChecked(page) set_bit(PG_checked, &(page)->flags)
52 static int ll_dir_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
57 /* returns the page unlocked, but with a reference */
58 static int ll_dir_readpage(struct file *file, struct page *page)
60 struct inode *inode = page->mapping->host;
61 struct ll_sb_info *sbi = ll_i2sbi(inode);
65 struct ptlrpc_request *request;
66 struct lustre_handle lockh;
67 struct lookup_intent it = {IT_READDIR};
71 if ((inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_SHIFT <= page->index){
72 memset(kmap(page), 0, PAGE_CACHE_SIZE);
74 GOTO(readpage_out, rc);
77 rc = ll_lock(inode, NULL, &it, &lockh);
78 request = (struct ptlrpc_request *)it.it_data;
79 ptlrpc_free_req(request);
81 CERROR("lock enqueue: err: %d\n", rc);
85 ldlm_lock_dump((void *)(unsigned long)lockh.addr);
87 if (Page_Uptodate(page)) {
88 CERROR("Explain this please?\n");
89 GOTO(readpage_out, rc);
92 offset = page->index << PAGE_SHIFT;
94 rc = mdc_readpage(&sbi->ll_mdc_conn, inode->i_ino,
95 S_IFDIR, offset, buf, &request);
97 ptlrpc_free_req(request);
102 SetPageUptodate(page);
105 rc = ll_unlock(LCK_PR, &lockh);
107 CERROR("ll_unlock: err: %d\n", rc);
109 } /* ll_dir_readpage */
111 struct address_space_operations ll_dir_aops = {
112 readpage: ll_dir_readpage,
113 prepare_write: ll_dir_prepare_write
116 int waitfor_one_page(struct page *page)
119 struct buffer_head *bh, *head = page->buffers;
124 if (buffer_req(bh) && !buffer_uptodate(bh))
126 } while ((bh = bh->b_this_page) != head);
131 * ext2 uses block-sized chunks. Arguably, sector-sized ones would be
132 * more robust, but we have what we have
134 static inline unsigned ext2_chunk_size(struct inode *inode)
136 return inode->i_sb->s_blocksize;
139 static inline void ext2_put_page(struct page *page)
142 page_cache_release(page);
145 static inline unsigned long dir_pages(struct inode *inode)
147 return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT;
150 extern void set_page_clean(struct page *page);
152 static int ext2_commit_chunk(struct page *page, unsigned from, unsigned to)
154 struct inode *dir = page->mapping->host;
155 loff_t new_size = (page->index << PAGE_CACHE_SHIFT) + to;
158 dir->i_version = ++event;
159 if (new_size > dir->i_size)
160 dir->i_size = new_size;
161 SetPageUptodate(page);
162 set_page_clean(page);
164 //page->mapping->a_ops->commit_write(NULL, page, from, to);
166 // err = waitfor_one_page(page);
170 static void ext2_check_page(struct page *page)
172 struct inode *dir = page->mapping->host;
173 unsigned chunk_size = ext2_chunk_size(dir);
174 char *kaddr = page_address(page);
175 // u32 max_inumber = le32_to_cpu(sb->u.ext2_sb.s_es->s_inodes_count);
176 unsigned offs, rec_len;
177 unsigned limit = PAGE_CACHE_SIZE;
181 if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) {
182 limit = dir->i_size & ~PAGE_CACHE_MASK;
183 if (limit & (chunk_size - 1)) {
184 CERROR("limit %d dir size %lld index %ld\n",
185 limit, dir->i_size, page->index);
188 for (offs = limit; offs<PAGE_CACHE_SIZE; offs += chunk_size) {
189 ext2_dirent *p = (ext2_dirent*)(kaddr + offs);
190 p->rec_len = cpu_to_le16(chunk_size);
197 for (offs = 0; offs <= limit - EXT2_DIR_REC_LEN(1); offs += rec_len) {
198 p = (ext2_dirent *)(kaddr + offs);
199 rec_len = le16_to_cpu(p->rec_len);
201 if (rec_len < EXT2_DIR_REC_LEN(1))
205 if (rec_len < EXT2_DIR_REC_LEN(p->name_len))
207 if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1))
209 // if (le32_to_cpu(p->inode) > max_inumber)
215 SetPageChecked(page);
218 /* Too bad, we had an error */
221 CERROR("ext2_check_page"
222 "size of directory #%lu is not a multiple of chunk size\n",
227 error = "rec_len is smaller than minimal";
230 error = "unaligned directory entry";
233 error = "rec_len is too small for name_len";
236 error = "directory entry across blocks";
239 // error = "inode out of bounds";
241 CERROR("ext2_check_page: bad entry in directory #%lu: %s - "
242 "offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
243 dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
244 (unsigned long) le32_to_cpu(p->inode),
245 rec_len, p->name_len);
248 p = (ext2_dirent *)(kaddr + offs);
249 CERROR("ext2_check_page"
250 "entry in directory #%lu spans the page boundary"
251 "offset=%lu, inode=%lu",
252 dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs,
253 (unsigned long) le32_to_cpu(p->inode));
255 SetPageChecked(page);
260 static struct page * ext2_get_page(struct inode *dir, unsigned long n)
262 struct address_space *mapping = dir->i_mapping;
263 struct page *page = read_cache_page(mapping, n,
264 (filler_t*)mapping->a_ops->readpage, NULL);
268 if (!Page_Uptodate(page))
270 if (!PageChecked(page))
271 ext2_check_page(page);
279 return ERR_PTR(-EIO);
283 * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure.
285 * len <= EXT2_NAME_LEN and de != NULL are guaranteed by caller.
287 static inline int ext2_match (int len, const char * const name,
288 struct ext2_dir_entry_2 * de)
290 if (len != de->name_len)
294 return !memcmp(name, de->name, len);
298 * p is at least 6 bytes before the end of page
300 static inline ext2_dirent *ext2_next_entry(ext2_dirent *p)
302 return (ext2_dirent *)((char*)p + le16_to_cpu(p->rec_len));
305 static inline unsigned
306 ext2_validate_entry(char *base, unsigned offset, unsigned mask)
308 ext2_dirent *de = (ext2_dirent*)(base + offset);
309 ext2_dirent *p = (ext2_dirent*)(base + (offset&mask));
310 while ((char*)p < (char*)de)
311 p = ext2_next_entry(p);
312 return (char *)p - base;
315 static unsigned char ext2_filetype_table[EXT2_FT_MAX] = {
316 [EXT2_FT_UNKNOWN] DT_UNKNOWN,
317 [EXT2_FT_REG_FILE] DT_REG,
318 [EXT2_FT_DIR] DT_DIR,
319 [EXT2_FT_CHRDEV] DT_CHR,
320 [EXT2_FT_BLKDEV] DT_BLK,
321 [EXT2_FT_FIFO] DT_FIFO,
322 [EXT2_FT_SOCK] DT_SOCK,
323 [EXT2_FT_SYMLINK] DT_LNK,
326 static unsigned int ll_dt2fmt[DT_WHT + 1] = {
328 [EXT2_FT_REG_FILE] S_IFREG,
329 [EXT2_FT_DIR] S_IFDIR,
330 [EXT2_FT_CHRDEV] S_IFCHR,
331 [EXT2_FT_BLKDEV] S_IFBLK,
332 [EXT2_FT_FIFO] S_IFIFO,
333 [EXT2_FT_SOCK] S_IFSOCK,
334 [EXT2_FT_SYMLINK] S_IFLNK
338 static unsigned char ext2_type_by_mode[S_IFMT >> S_SHIFT] = {
339 [S_IFREG >> S_SHIFT] EXT2_FT_REG_FILE,
340 [S_IFDIR >> S_SHIFT] EXT2_FT_DIR,
341 [S_IFCHR >> S_SHIFT] EXT2_FT_CHRDEV,
342 [S_IFBLK >> S_SHIFT] EXT2_FT_BLKDEV,
343 [S_IFIFO >> S_SHIFT] EXT2_FT_FIFO,
344 [S_IFSOCK >> S_SHIFT] EXT2_FT_SOCK,
345 [S_IFLNK >> S_SHIFT] EXT2_FT_SYMLINK,
348 static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode)
350 mode_t mode = inode->i_mode;
351 de->file_type = ext2_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
354 int ll_readdir(struct file * filp, void * dirent, filldir_t filldir)
356 loff_t pos = filp->f_pos;
357 struct inode *inode = filp->f_dentry->d_inode;
358 // XXX struct super_block *sb = inode->i_sb;
359 unsigned offset = pos & ~PAGE_CACHE_MASK;
360 unsigned long n = pos >> PAGE_CACHE_SHIFT;
361 unsigned long npages = dir_pages(inode);
362 unsigned chunk_mask = ~(ext2_chunk_size(inode)-1);
363 unsigned char *types = NULL;
364 int need_revalidate = (filp->f_version != inode->i_version);
367 if (pos > inode->i_size - EXT2_DIR_REC_LEN(1))
370 types = ext2_filetype_table;
372 for ( ; n < npages; n++, offset = 0) {
375 struct page *page = ext2_get_page(inode, n);
379 kaddr = page_address(page);
380 if (need_revalidate) {
381 offset = ext2_validate_entry(kaddr, offset, chunk_mask);
384 de = (ext2_dirent *)(kaddr+offset);
385 limit = kaddr + PAGE_CACHE_SIZE - EXT2_DIR_REC_LEN(1);
386 for ( ;(char*)de <= limit; de = ext2_next_entry(de))
389 unsigned char d_type = DT_UNKNOWN;
391 if (types && de->file_type < EXT2_FT_MAX)
392 d_type = types[de->file_type];
394 offset = (char *)de - kaddr;
395 over = filldir(dirent, de->name, de->name_len,
396 (n<<PAGE_CACHE_SHIFT) | offset,
397 le32_to_cpu(de->inode), d_type);
407 filp->f_pos = (n << PAGE_CACHE_SHIFT) | offset;
408 filp->f_version = inode->i_version;
416 * finds an entry in the specified directory with the wanted name. It
417 * returns the page in which the entry was found, and the entry itself
418 * (as a parameter - res_dir). Page is returned mapped and unlocked.
419 * Entry is guaranteed to be valid.
421 struct ext2_dir_entry_2 * ext2_find_entry (struct inode * dir,
422 struct dentry *dentry, struct page ** res_page)
424 const char *name = dentry->d_name.name;
425 int namelen = dentry->d_name.len;
426 unsigned reclen = EXT2_DIR_REC_LEN(namelen);
427 unsigned long start, n;
428 unsigned long npages = dir_pages(dir);
429 struct page *page = NULL;
435 // start = dir->u.ext2_i.i_dir_start_lookup;
442 page = ext2_get_page(dir, n);
444 kaddr = page_address(page);
445 de = (ext2_dirent *) kaddr;
446 kaddr += PAGE_CACHE_SIZE - reclen;
447 while ((char *) de <= kaddr) {
448 if (ext2_match (namelen, name, de))
450 de = ext2_next_entry(de);
456 } while (n != start);
461 // dir->u.ext2_i.i_dir_start_lookup = n;
465 struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p)
467 struct page *page = ext2_get_page(dir, 0);
468 ext2_dirent *de = NULL;
471 de = ext2_next_entry((ext2_dirent *) page_address(page));
477 obd_id ll_inode_by_name(struct inode * dir, struct dentry *dentry, int *type)
480 struct ext2_dir_entry_2 * de;
483 de = ext2_find_entry (dir, dentry, &page);
485 res = le32_to_cpu(de->inode);
486 *type = ll_dt2fmt[de->file_type];
488 page_cache_release(page);
493 /* Releases the page */
494 void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
495 struct page *page, struct inode *inode)
497 unsigned from = (char *) de - (char *) page_address(page);
498 unsigned to = from + le16_to_cpu(de->rec_len);
502 err = page->mapping->a_ops->prepare_write(NULL, page, from, to);
505 de->inode = cpu_to_le32(inode->i_ino);
506 ext2_set_de_type (de, inode);
507 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
508 err = ext2_commit_chunk(page, from, to);
516 int ll_add_link (struct dentry *dentry, struct inode *inode)
518 struct inode *dir = dentry->d_parent->d_inode;
519 const char *name = dentry->d_name.name;
520 int namelen = dentry->d_name.len;
521 unsigned reclen = EXT2_DIR_REC_LEN(namelen);
522 unsigned short rec_len, name_len;
523 struct page *page = NULL;
525 unsigned long npages = dir_pages(dir);
531 /* We take care of directory expansion in the same loop */
532 for (n = 0; n <= npages; n++) {
533 page = ext2_get_page(dir, n);
537 kaddr = page_address(page);
538 de = (ext2_dirent *)kaddr;
539 kaddr += PAGE_CACHE_SIZE - reclen;
540 while ((char *)de <= kaddr) {
542 if (ext2_match (namelen, name, de))
544 name_len = EXT2_DIR_REC_LEN(de->name_len);
545 rec_len = le16_to_cpu(de->rec_len);
546 if ( n==npages && rec_len == 0) {
547 CERROR("Fatal dir behaviour\n");
550 if (!de->inode && rec_len >= reclen)
552 if (rec_len >= name_len + reclen)
554 de = (ext2_dirent *) ((char *) de + rec_len);
562 from = (char*)de - (char*)page_address(page);
565 err = page->mapping->a_ops->prepare_write(NULL, page, from, to);
569 ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len);
570 de1->rec_len = cpu_to_le16(rec_len - name_len);
571 de->rec_len = cpu_to_le16(name_len);
574 de->name_len = namelen;
575 memcpy (de->name, name, namelen);
576 de->inode = cpu_to_le32(inode->i_ino);
577 ext2_set_de_type (de, inode);
578 CDEBUG(D_INODE, "type set to %o\n", de->file_type);
579 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
580 err = ext2_commit_chunk(page, from, to);
582 // change_inode happens with the commit_chunk
583 /* XXX OFFSET_CACHE */
594 * ext2_delete_entry deletes a directory entry by merging it with the
595 * previous entry. Page is up-to-date. Releases the page.
597 int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page )
599 struct address_space *mapping = page->mapping;
600 struct inode *inode = mapping->host;
601 char *kaddr = page_address(page);
602 unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1);
603 unsigned to = ((char*)dir - kaddr) + le16_to_cpu(dir->rec_len);
604 ext2_dirent * pde = NULL;
605 ext2_dirent * de = (ext2_dirent *) (kaddr + from);
608 while ((char*)de < (char*)dir) {
610 de = ext2_next_entry(de);
613 from = (char*)pde - (char*)page_address(page);
615 err = mapping->a_ops->prepare_write(NULL, page, from, to);
619 pde->rec_len = cpu_to_le16(to-from);
621 inode->i_ctime = inode->i_mtime = CURRENT_TIME;
622 err = ext2_commit_chunk(page, from, to);
629 * Set the first fragment of directory.
631 int ext2_make_empty(struct inode *inode, struct inode *parent)
633 struct address_space *mapping = inode->i_mapping;
634 struct page *page = grab_cache_page(mapping, 0);
635 unsigned chunk_size = ext2_chunk_size(inode);
636 struct ext2_dir_entry_2 * de;
647 err = mapping->a_ops->prepare_write(NULL, page, 0, chunk_size);
651 de = (struct ext2_dir_entry_2 *) base;
653 de->rec_len = cpu_to_le16(EXT2_DIR_REC_LEN(1));
654 memcpy (de->name, ".\0\0", 4);
655 de->inode = cpu_to_le32(inode->i_ino);
656 ext2_set_de_type (de, inode);
658 de = (struct ext2_dir_entry_2 *) (base + EXT2_DIR_REC_LEN(1));
660 de->rec_len = cpu_to_le16(chunk_size - EXT2_DIR_REC_LEN(1));
661 de->inode = cpu_to_le32(parent->i_ino);
662 memcpy (de->name, "..\0", 4);
663 ext2_set_de_type (de, inode);
665 err = ext2_commit_chunk(page, 0, chunk_size);
669 page_cache_release(page);
675 * routine to check that the specified directory is empty (for rmdir)
677 int ext2_empty_dir (struct inode * inode)
679 struct page *page = NULL;
680 unsigned long i, npages = dir_pages(inode);
682 for (i = 0; i < npages; i++) {
685 page = ext2_get_page(inode, i);
690 kaddr = page_address(page);
691 de = (ext2_dirent *)kaddr;
692 kaddr += PAGE_CACHE_SIZE-EXT2_DIR_REC_LEN(1);
694 while ((char *)de <= kaddr) {
695 if (de->inode != 0) {
696 /* check for . and .. */
697 if (de->name[0] != '.')
699 if (de->name_len > 2)
701 if (de->name_len < 2) {
703 cpu_to_le32(inode->i_ino))
705 } else if (de->name[1] != '.')
708 de = ext2_next_entry(de);
719 struct file_operations ll_dir_operations = {
720 read: generic_read_dir,