blob: ea5e6cb7e2a5e345b514d10b5f39a54ec021dbfe [file] [log] [blame]
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001/*
Mingming Cao617ba132006-10-11 01:20:53 -07002 * linux/fs/ext4/dir.c
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003 *
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)
8 *
9 * from
10 *
11 * linux/fs/minix/dir.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
Mingming Cao617ba132006-10-11 01:20:53 -070015 * ext4 directory handling functions
Dave Kleikampac27a0e2006-10-11 01:20:50 -070016 *
17 * Big-endian to little-endian byte-swapping/bitmaps by
18 * David S. Miller (davem@caip.rutgers.edu), 1995
19 *
20 * Hash Tree Directory indexing (c) 2001 Daniel Phillips
21 *
22 */
23
24#include <linux/fs.h>
Mingming Caodab291a2006-10-11 01:21:01 -070025#include <linux/jbd2.h>
Dave Kleikampac27a0e2006-10-11 01:20:50 -070026#include <linux/buffer_head.h>
Dave Kleikampac27a0e2006-10-11 01:20:50 -070027#include <linux/slab.h>
28#include <linux/rbtree.h>
Christoph Hellwig3dcf5452008-04-29 18:13:32 -040029#include "ext4.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070030
Mingming Cao617ba132006-10-11 01:20:53 -070031static unsigned char ext4_filetype_table[] = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -070032 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
33};
34
Mingming Cao617ba132006-10-11 01:20:53 -070035static int ext4_readdir(struct file *, void *, filldir_t);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -040036static int ext4_dx_readdir(struct file *filp,
37 void *dirent, filldir_t filldir);
38static int ext4_release_dir(struct inode *inode,
39 struct file *filp);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070040
Mingming Cao617ba132006-10-11 01:20:53 -070041const struct file_operations ext4_dir_operations = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -070042 .llseek = generic_file_llseek,
43 .read = generic_read_dir,
Mingming Cao617ba132006-10-11 01:20:53 -070044 .readdir = ext4_readdir, /* we take BKL. needed?*/
Andi Kleen5cdd7b22008-04-29 22:03:54 -040045 .unlocked_ioctl = ext4_ioctl,
Dave Kleikampac27a0e2006-10-11 01:20:50 -070046#ifdef CONFIG_COMPAT
Mingming Cao617ba132006-10-11 01:20:53 -070047 .compat_ioctl = ext4_compat_ioctl,
Dave Kleikampac27a0e2006-10-11 01:20:50 -070048#endif
Andi Kleen642be6e2008-02-25 17:20:46 -050049 .fsync = ext4_sync_file,
Mingming Cao617ba132006-10-11 01:20:53 -070050 .release = ext4_release_dir,
Dave Kleikampac27a0e2006-10-11 01:20:50 -070051};
52
53
54static unsigned char get_dtype(struct super_block *sb, int filetype)
55{
Mingming Cao617ba132006-10-11 01:20:53 -070056 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
57 (filetype >= EXT4_FT_MAX))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070058 return DT_UNKNOWN;
59
Mingming Cao617ba132006-10-11 01:20:53 -070060 return (ext4_filetype_table[filetype]);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070061}
62
63
Theodore Ts'oaf5bc922008-09-08 22:25:24 -040064int ext4_check_dir_entry(const char *function, struct inode *dir,
65 struct ext4_dir_entry_2 *de,
66 struct buffer_head *bh,
Theodore Ts'o498e5f22008-11-05 00:14:04 -050067 unsigned int offset)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070068{
Theodore Ts'oaf5bc922008-09-08 22:25:24 -040069 const char *error_msg = NULL;
Wei Yongjun3d0518f2009-02-14 23:01:36 -050070 const int rlen = ext4_rec_len_from_disk(de->rec_len,
71 dir->i_sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070072
Mingming Cao617ba132006-10-11 01:20:53 -070073 if (rlen < EXT4_DIR_REC_LEN(1))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070074 error_msg = "rec_len is smaller than minimal";
75 else if (rlen % 4 != 0)
76 error_msg = "rec_len % 4 != 0";
Mingming Cao617ba132006-10-11 01:20:53 -070077 else if (rlen < EXT4_DIR_REC_LEN(de->name_len))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070078 error_msg = "rec_len is too small for name_len";
79 else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize)
80 error_msg = "directory entry across blocks";
81 else if (le32_to_cpu(de->inode) >
Mingming Cao617ba132006-10-11 01:20:53 -070082 le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070083 error_msg = "inode out of bounds";
84
85 if (error_msg != NULL)
Theodore Ts'o24676da2010-05-16 21:00:00 -040086 ext4_error_inode(function, dir,
87 "bad entry in directory: %s - block=%llu"
Toshiyuki Okajimab8b8afe2010-03-02 00:21:35 -050088 "offset=%u(%u), inode=%u, rec_len=%d, name_len=%d",
Theodore Ts'o24676da2010-05-16 21:00:00 -040089 error_msg, (unsigned long long) bh->b_blocknr,
Toshiyuki Okajimab8b8afe2010-03-02 00:21:35 -050090 (unsigned) (offset%bh->b_size), offset,
Theodore Ts'o498e5f22008-11-05 00:14:04 -050091 le32_to_cpu(de->inode),
Dave Kleikampac27a0e2006-10-11 01:20:50 -070092 rlen, de->name_len);
93 return error_msg == NULL ? 1 : 0;
94}
95
Theodore Ts'oaf5bc922008-09-08 22:25:24 -040096static int ext4_readdir(struct file *filp,
97 void *dirent, filldir_t filldir)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070098{
99 int error = 0;
Theodore Ts'o498e5f22008-11-05 00:14:04 -0500100 unsigned int offset;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700101 int i, stored;
Mingming Cao617ba132006-10-11 01:20:53 -0700102 struct ext4_dir_entry_2 *de;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700103 struct super_block *sb;
104 int err;
Josef "Jeff" Sipek9d549892006-12-08 02:36:38 -0800105 struct inode *inode = filp->f_path.dentry->d_inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700106 int ret = 0;
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400107 int dir_has_error = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700108
109 sb = inode->i_sb;
110
Mingming Cao617ba132006-10-11 01:20:53 -0700111 if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
112 EXT4_FEATURE_COMPAT_DIR_INDEX) &&
Dmitry Monakhov12e9b892010-05-16 22:00:00 -0400113 ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) ||
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700114 ((inode->i_size >> sb->s_blocksize_bits) == 1))) {
Mingming Cao617ba132006-10-11 01:20:53 -0700115 err = ext4_dx_readdir(filp, dirent, filldir);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700116 if (err != ERR_BAD_DX_DIR) {
117 ret = err;
118 goto out;
119 }
120 /*
121 * We don't set the inode dirty flag since it's not
122 * critical that it get flushed back to the disk.
123 */
Dmitry Monakhov12e9b892010-05-16 22:00:00 -0400124 ext4_clear_inode_flag(filp->f_path.dentry->d_inode, EXT4_INODE_INDEX);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700125 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700126 stored = 0;
127 offset = filp->f_pos & (sb->s_blocksize - 1);
128
129 while (!error && !stored && filp->f_pos < inode->i_size) {
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400130 struct ext4_map_blocks map;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700131 struct buffer_head *bh = NULL;
132
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400133 map.m_lblk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb);
134 map.m_len = 1;
135 err = ext4_map_blocks(NULL, inode, &map, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700136 if (err > 0) {
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400137 pgoff_t index = map.m_pblk >>
Fengguang Wudc7868f2007-07-19 01:48:04 -0700138 (PAGE_CACHE_SHIFT - inode->i_blkbits);
139 if (!ra_has_index(&filp->f_ra, index))
Rusty Russellcf914a72007-07-19 01:48:08 -0700140 page_cache_sync_readahead(
Fengguang Wudc7868f2007-07-19 01:48:04 -0700141 sb->s_bdev->bd_inode->i_mapping,
142 &filp->f_ra, filp,
Rusty Russellcf914a72007-07-19 01:48:08 -0700143 index, 1);
Fengguang Wuf4e6b492007-10-16 01:24:33 -0700144 filp->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400145 bh = ext4_bread(NULL, inode, map.m_lblk, 0, &err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700146 }
147
148 /*
149 * We ignore I/O errors on directories so users have a chance
150 * of recovering data when there's a bad sector
151 */
152 if (!bh) {
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400153 if (!dir_has_error) {
Theodore Ts'o24676da2010-05-16 21:00:00 -0400154 EXT4_ERROR_INODE(inode, "directory "
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400155 "contains a hole at offset %Lu",
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400156 (unsigned long long) filp->f_pos);
157 dir_has_error = 1;
158 }
Eric Sandeene6c40212006-12-06 20:36:28 -0800159 /* corrupt size? Maybe no more blocks to read */
160 if (filp->f_pos > inode->i_blocks << 9)
161 break;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700162 filp->f_pos += sb->s_blocksize - offset;
163 continue;
164 }
165
166revalidate:
167 /* If the dir block has changed since the last call to
168 * readdir(2), then we might be pointing to an invalid
169 * dirent right now. Scan from the start of the block
170 * to make sure. */
171 if (filp->f_version != inode->i_version) {
172 for (i = 0; i < sb->s_blocksize && i < offset; ) {
Mingming Cao617ba132006-10-11 01:20:53 -0700173 de = (struct ext4_dir_entry_2 *)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700174 (bh->b_data + i);
175 /* It's too expensive to do a full
176 * dirent test each time round this
177 * loop, but we do have to test at
178 * least that it is non-zero. A
179 * failure will be detected in the
180 * dirent test below. */
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500181 if (ext4_rec_len_from_disk(de->rec_len,
182 sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700183 break;
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500184 i += ext4_rec_len_from_disk(de->rec_len,
185 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700186 }
187 offset = i;
188 filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
189 | offset;
190 filp->f_version = inode->i_version;
191 }
192
193 while (!error && filp->f_pos < inode->i_size
194 && offset < sb->s_blocksize) {
Mingming Cao617ba132006-10-11 01:20:53 -0700195 de = (struct ext4_dir_entry_2 *) (bh->b_data + offset);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400196 if (!ext4_check_dir_entry("ext4_readdir", inode, de,
197 bh, offset)) {
Andrew Morton63f57932006-10-11 01:21:24 -0700198 /*
199 * On error, skip the f_pos to the next block
200 */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700201 filp->f_pos = (filp->f_pos |
202 (sb->s_blocksize - 1)) + 1;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400203 brelse(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700204 ret = stored;
205 goto out;
206 }
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500207 offset += ext4_rec_len_from_disk(de->rec_len,
208 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700209 if (le32_to_cpu(de->inode)) {
210 /* We might block in the next section
211 * if the data destination is
212 * currently swapped out. So, use a
213 * version stamp to detect whether or
214 * not the directory has been modified
215 * during the copy operation.
216 */
Mathieu Desnoyers2b47c362007-10-16 23:27:21 -0700217 u64 version = filp->f_version;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700218
219 error = filldir(dirent, de->name,
220 de->name_len,
221 filp->f_pos,
222 le32_to_cpu(de->inode),
223 get_dtype(sb, de->file_type));
224 if (error)
225 break;
226 if (version != filp->f_version)
227 goto revalidate;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400228 stored++;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700229 }
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500230 filp->f_pos += ext4_rec_len_from_disk(de->rec_len,
231 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700232 }
233 offset = 0;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400234 brelse(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700235 }
236out:
237 return ret;
238}
239
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700240/*
241 * These functions convert from the major/minor hash to an f_pos
242 * value.
243 *
244 * Currently we only use major hash numer. This is unfortunate, but
245 * on 32-bit machines, the same VFS interface is used for lseek and
246 * llseek, so if we use the 64 bit offset, then the 32-bit versions of
247 * lseek/telldir/seekdir will blow out spectacularly, and from within
248 * the ext2 low-level routine, we don't know if we're being called by
249 * a 64-bit version of the system call or the 32-bit version of the
250 * system call. Worse yet, NFSv2 only allows for a 32-bit readdir
251 * cookie. Sigh.
252 */
253#define hash2pos(major, minor) (major >> 1)
254#define pos2maj_hash(pos) ((pos << 1) & 0xffffffff)
255#define pos2min_hash(pos) (0)
256
257/*
258 * This structure holds the nodes of the red-black tree used to store
259 * the directory entry in hash order.
260 */
261struct fname {
262 __u32 hash;
263 __u32 minor_hash;
264 struct rb_node rb_hash;
265 struct fname *next;
266 __u32 inode;
267 __u8 name_len;
268 __u8 file_type;
269 char name[0];
270};
271
272/*
273 * This functoin implements a non-recursive way of freeing all of the
274 * nodes in the red-black tree.
275 */
276static void free_rb_tree_fname(struct rb_root *root)
277{
278 struct rb_node *n = root->rb_node;
279 struct rb_node *parent;
280 struct fname *fname;
281
282 while (n) {
283 /* Do the node's children first */
Shen Feng69baee02008-07-11 19:27:31 -0400284 if (n->rb_left) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700285 n = n->rb_left;
286 continue;
287 }
288 if (n->rb_right) {
289 n = n->rb_right;
290 continue;
291 }
292 /*
293 * The node has no children; free it, and then zero
294 * out parent's link to it. Finally go to the
295 * beginning of the loop and try to free the parent
296 * node.
297 */
298 parent = rb_parent(n);
299 fname = rb_entry(n, struct fname, rb_hash);
300 while (fname) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400301 struct fname *old = fname;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700302 fname = fname->next;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400303 kfree(old);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700304 }
305 if (!parent)
Venkatesh Pallipadi64e290e2010-03-04 22:25:21 -0500306 *root = RB_ROOT;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700307 else if (parent->rb_left == n)
308 parent->rb_left = NULL;
309 else if (parent->rb_right == n)
310 parent->rb_right = NULL;
311 n = parent;
312 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700313}
314
315
Shen Feng69baee02008-07-11 19:27:31 -0400316static struct dir_private_info *ext4_htree_create_dir_info(loff_t pos)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700317{
318 struct dir_private_info *p;
319
Shen Feng69baee02008-07-11 19:27:31 -0400320 p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700321 if (!p)
322 return NULL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700323 p->curr_hash = pos2maj_hash(pos);
324 p->curr_minor_hash = pos2min_hash(pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700325 return p;
326}
327
Mingming Cao617ba132006-10-11 01:20:53 -0700328void ext4_htree_free_dir_info(struct dir_private_info *p)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700329{
330 free_rb_tree_fname(&p->root);
331 kfree(p);
332}
333
334/*
335 * Given a directory entry, enter it into the fname rb tree.
336 */
Mingming Cao617ba132006-10-11 01:20:53 -0700337int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700338 __u32 minor_hash,
Mingming Cao617ba132006-10-11 01:20:53 -0700339 struct ext4_dir_entry_2 *dirent)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700340{
341 struct rb_node **p, *parent = NULL;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400342 struct fname *fname, *new_fn;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700343 struct dir_private_info *info;
344 int len;
345
346 info = (struct dir_private_info *) dir_file->private_data;
347 p = &info->root.rb_node;
348
349 /* Create and allocate the fname structure */
350 len = sizeof(struct fname) + dirent->name_len + 1;
351 new_fn = kzalloc(len, GFP_KERNEL);
352 if (!new_fn)
353 return -ENOMEM;
354 new_fn->hash = hash;
355 new_fn->minor_hash = minor_hash;
356 new_fn->inode = le32_to_cpu(dirent->inode);
357 new_fn->name_len = dirent->name_len;
358 new_fn->file_type = dirent->file_type;
359 memcpy(new_fn->name, dirent->name, dirent->name_len);
360 new_fn->name[dirent->name_len] = 0;
361
362 while (*p) {
363 parent = *p;
364 fname = rb_entry(parent, struct fname, rb_hash);
365
366 /*
367 * If the hash and minor hash match up, then we put
368 * them on a linked list. This rarely happens...
369 */
370 if ((new_fn->hash == fname->hash) &&
371 (new_fn->minor_hash == fname->minor_hash)) {
372 new_fn->next = fname->next;
373 fname->next = new_fn;
374 return 0;
375 }
376
377 if (new_fn->hash < fname->hash)
378 p = &(*p)->rb_left;
379 else if (new_fn->hash > fname->hash)
380 p = &(*p)->rb_right;
381 else if (new_fn->minor_hash < fname->minor_hash)
382 p = &(*p)->rb_left;
383 else /* if (new_fn->minor_hash > fname->minor_hash) */
384 p = &(*p)->rb_right;
385 }
386
387 rb_link_node(&new_fn->rb_hash, parent, p);
388 rb_insert_color(&new_fn->rb_hash, &info->root);
389 return 0;
390}
391
392
393
394/*
Mingming Cao617ba132006-10-11 01:20:53 -0700395 * This is a helper function for ext4_dx_readdir. It calls filldir
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700396 * for all entres on the fname linked list. (Normally there is only
397 * one entry on the linked list, unless there are 62 bit hash collisions.)
398 */
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400399static int call_filldir(struct file *filp, void *dirent,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700400 filldir_t filldir, struct fname *fname)
401{
402 struct dir_private_info *info = filp->private_data;
403 loff_t curr_pos;
Josef "Jeff" Sipek9d549892006-12-08 02:36:38 -0800404 struct inode *inode = filp->f_path.dentry->d_inode;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400405 struct super_block *sb;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700406 int error;
407
408 sb = inode->i_sb;
409
410 if (!fname) {
Theodore Ts'oabda1412009-01-06 00:20:32 -0500411 printk(KERN_ERR "EXT4-fs: call_filldir: called with "
Theodore Ts'o47760042008-09-08 23:00:52 -0400412 "null fname?!?\n");
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700413 return 0;
414 }
415 curr_pos = hash2pos(fname->hash, fname->minor_hash);
416 while (fname) {
417 error = filldir(dirent, fname->name,
418 fname->name_len, curr_pos,
419 fname->inode,
420 get_dtype(sb, fname->file_type));
421 if (error) {
422 filp->f_pos = curr_pos;
Theodore Ts'od0156412008-08-19 21:57:43 -0400423 info->extra_fname = fname;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700424 return error;
425 }
426 fname = fname->next;
427 }
428 return 0;
429}
430
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400431static int ext4_dx_readdir(struct file *filp,
432 void *dirent, filldir_t filldir)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700433{
434 struct dir_private_info *info = filp->private_data;
Josef "Jeff" Sipek9d549892006-12-08 02:36:38 -0800435 struct inode *inode = filp->f_path.dentry->d_inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700436 struct fname *fname;
437 int ret;
438
439 if (!info) {
Shen Feng69baee02008-07-11 19:27:31 -0400440 info = ext4_htree_create_dir_info(filp->f_pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700441 if (!info)
442 return -ENOMEM;
443 filp->private_data = info;
444 }
445
Mingming Cao617ba132006-10-11 01:20:53 -0700446 if (filp->f_pos == EXT4_HTREE_EOF)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700447 return 0; /* EOF */
448
449 /* Some one has messed with f_pos; reset the world */
450 if (info->last_pos != filp->f_pos) {
451 free_rb_tree_fname(&info->root);
452 info->curr_node = NULL;
453 info->extra_fname = NULL;
454 info->curr_hash = pos2maj_hash(filp->f_pos);
455 info->curr_minor_hash = pos2min_hash(filp->f_pos);
456 }
457
458 /*
459 * If there are any leftover names on the hash collision
460 * chain, return them first.
461 */
Theodore Ts'od0156412008-08-19 21:57:43 -0400462 if (info->extra_fname) {
463 if (call_filldir(filp, dirent, filldir, info->extra_fname))
464 goto finished;
Theodore Ts'od0156412008-08-19 21:57:43 -0400465 info->extra_fname = NULL;
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400466 goto next_node;
Theodore Ts'od0156412008-08-19 21:57:43 -0400467 } else if (!info->curr_node)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700468 info->curr_node = rb_first(&info->root);
469
470 while (1) {
471 /*
472 * Fill the rbtree if we have no more entries,
473 * or the inode has changed since we last read in the
474 * cached entries.
475 */
476 if ((!info->curr_node) ||
477 (filp->f_version != inode->i_version)) {
478 info->curr_node = NULL;
479 free_rb_tree_fname(&info->root);
480 filp->f_version = inode->i_version;
Mingming Cao617ba132006-10-11 01:20:53 -0700481 ret = ext4_htree_fill_tree(filp, info->curr_hash,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700482 info->curr_minor_hash,
483 &info->next_hash);
484 if (ret < 0)
485 return ret;
486 if (ret == 0) {
Mingming Cao617ba132006-10-11 01:20:53 -0700487 filp->f_pos = EXT4_HTREE_EOF;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700488 break;
489 }
490 info->curr_node = rb_first(&info->root);
491 }
492
493 fname = rb_entry(info->curr_node, struct fname, rb_hash);
494 info->curr_hash = fname->hash;
495 info->curr_minor_hash = fname->minor_hash;
496 if (call_filldir(filp, dirent, filldir, fname))
497 break;
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400498 next_node:
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700499 info->curr_node = rb_next(info->curr_node);
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400500 if (info->curr_node) {
501 fname = rb_entry(info->curr_node, struct fname,
502 rb_hash);
503 info->curr_hash = fname->hash;
504 info->curr_minor_hash = fname->minor_hash;
505 } else {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700506 if (info->next_hash == ~0) {
Mingming Cao617ba132006-10-11 01:20:53 -0700507 filp->f_pos = EXT4_HTREE_EOF;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700508 break;
509 }
510 info->curr_hash = info->next_hash;
511 info->curr_minor_hash = 0;
512 }
513 }
514finished:
515 info->last_pos = filp->f_pos;
516 return 0;
517}
518
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400519static int ext4_release_dir(struct inode *inode, struct file *filp)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700520{
Andrew Morton63f57932006-10-11 01:21:24 -0700521 if (filp->private_data)
Mingming Cao617ba132006-10-11 01:20:53 -0700522 ext4_htree_free_dir_info(filp->private_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700523
524 return 0;
525}