blob: b86786202643bdd8044ee85fb72a0a21bc2c9bef [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
Theodore Ts'oaf5bc922008-09-08 22:25:24 -040035static int ext4_dx_readdir(struct file *filp,
36 void *dirent, filldir_t filldir);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070037
38static unsigned char get_dtype(struct super_block *sb, int filetype)
39{
Mingming Cao617ba132006-10-11 01:20:53 -070040 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
41 (filetype >= EXT4_FT_MAX))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070042 return DT_UNKNOWN;
43
Mingming Cao617ba132006-10-11 01:20:53 -070044 return (ext4_filetype_table[filetype]);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070045}
46
Fan Yongd1f52732012-03-18 22:44:40 -040047/**
48 * Check if the given dir-inode refers to an htree-indexed directory
49 * (or a directory which chould potentially get coverted to use htree
50 * indexing).
51 *
52 * Return 1 if it is a dx dir, 0 if not
53 */
54static int is_dx_dir(struct inode *inode)
55{
56 struct super_block *sb = inode->i_sb;
57
58 if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
59 EXT4_FEATURE_COMPAT_DIR_INDEX) &&
60 ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) ||
61 ((inode->i_size >> sb->s_blocksize_bits) == 1)))
62 return 1;
63
64 return 0;
65}
66
Theodore Ts'ocad3f002010-12-19 22:07:02 -050067/*
68 * Return 0 if the directory entry is OK, and 1 if there is a problem
69 *
70 * Note: this is the opposite of what ext2 and ext3 historically returned...
71 */
Theodore Ts'o60fd4da2010-07-27 11:54:40 -040072int __ext4_check_dir_entry(const char *function, unsigned int line,
Theodore Ts'of7c21172011-01-10 12:10:55 -050073 struct inode *dir, struct file *filp,
Theodore Ts'o60fd4da2010-07-27 11:54:40 -040074 struct ext4_dir_entry_2 *de,
75 struct buffer_head *bh,
76 unsigned int offset)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070077{
Theodore Ts'oaf5bc922008-09-08 22:25:24 -040078 const char *error_msg = NULL;
Wei Yongjun3d0518f2009-02-14 23:01:36 -050079 const int rlen = ext4_rec_len_from_disk(de->rec_len,
80 dir->i_sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070081
Theodore Ts'ocad3f002010-12-19 22:07:02 -050082 if (unlikely(rlen < EXT4_DIR_REC_LEN(1)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070083 error_msg = "rec_len is smaller than minimal";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050084 else if (unlikely(rlen % 4 != 0))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070085 error_msg = "rec_len % 4 != 0";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050086 else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070087 error_msg = "rec_len is too small for name_len";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050088 else if (unlikely(((char *) de - bh->b_data) + rlen >
89 dir->i_sb->s_blocksize))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070090 error_msg = "directory entry across blocks";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050091 else if (unlikely(le32_to_cpu(de->inode) >
92 le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070093 error_msg = "inode out of bounds";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050094 else
95 return 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070096
Theodore Ts'of7c21172011-01-10 12:10:55 -050097 if (filp)
Dan Carpenter4fda4002012-02-20 17:53:05 -050098 ext4_error_file(filp, function, line, bh->b_blocknr,
Theodore Ts'of7c21172011-01-10 12:10:55 -050099 "bad entry in directory: %s - offset=%u(%u), "
100 "inode=%u, rec_len=%d, name_len=%d",
Dan Carpenter4fda4002012-02-20 17:53:05 -0500101 error_msg, (unsigned) (offset % bh->b_size),
Theodore Ts'of7c21172011-01-10 12:10:55 -0500102 offset, le32_to_cpu(de->inode),
103 rlen, de->name_len);
104 else
Dan Carpenter4fda4002012-02-20 17:53:05 -0500105 ext4_error_inode(dir, function, line, bh->b_blocknr,
Theodore Ts'of7c21172011-01-10 12:10:55 -0500106 "bad entry in directory: %s - offset=%u(%u), "
107 "inode=%u, rec_len=%d, name_len=%d",
Dan Carpenter4fda4002012-02-20 17:53:05 -0500108 error_msg, (unsigned) (offset % bh->b_size),
Theodore Ts'of7c21172011-01-10 12:10:55 -0500109 offset, le32_to_cpu(de->inode),
110 rlen, de->name_len);
111
Theodore Ts'ocad3f002010-12-19 22:07:02 -0500112 return 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700113}
114
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400115static int ext4_readdir(struct file *filp,
116 void *dirent, filldir_t filldir)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700117{
118 int error = 0;
Theodore Ts'o498e5f22008-11-05 00:14:04 -0500119 unsigned int offset;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700120 int i, stored;
Mingming Cao617ba132006-10-11 01:20:53 -0700121 struct ext4_dir_entry_2 *de;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700122 int err;
Josef "Jeff" Sipek9d549892006-12-08 02:36:38 -0800123 struct inode *inode = filp->f_path.dentry->d_inode;
Fan Yongd1f52732012-03-18 22:44:40 -0400124 struct super_block *sb = inode->i_sb;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700125 int ret = 0;
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400126 int dir_has_error = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700127
Fan Yongd1f52732012-03-18 22:44:40 -0400128 if (is_dx_dir(inode)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700129 err = ext4_dx_readdir(filp, dirent, filldir);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700130 if (err != ERR_BAD_DX_DIR) {
131 ret = err;
132 goto out;
133 }
134 /*
135 * We don't set the inode dirty flag since it's not
136 * critical that it get flushed back to the disk.
137 */
Theodore Ts'o07a03822010-06-14 09:54:48 -0400138 ext4_clear_inode_flag(filp->f_path.dentry->d_inode,
139 EXT4_INODE_INDEX);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700140 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700141 stored = 0;
142 offset = filp->f_pos & (sb->s_blocksize - 1);
143
144 while (!error && !stored && filp->f_pos < inode->i_size) {
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400145 struct ext4_map_blocks map;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700146 struct buffer_head *bh = NULL;
147
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400148 map.m_lblk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb);
149 map.m_len = 1;
150 err = ext4_map_blocks(NULL, inode, &map, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700151 if (err > 0) {
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400152 pgoff_t index = map.m_pblk >>
Fengguang Wudc7868f2007-07-19 01:48:04 -0700153 (PAGE_CACHE_SHIFT - inode->i_blkbits);
154 if (!ra_has_index(&filp->f_ra, index))
Rusty Russellcf914a72007-07-19 01:48:08 -0700155 page_cache_sync_readahead(
Fengguang Wudc7868f2007-07-19 01:48:04 -0700156 sb->s_bdev->bd_inode->i_mapping,
157 &filp->f_ra, filp,
Rusty Russellcf914a72007-07-19 01:48:08 -0700158 index, 1);
Fengguang Wuf4e6b492007-10-16 01:24:33 -0700159 filp->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400160 bh = ext4_bread(NULL, inode, map.m_lblk, 0, &err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700161 }
162
163 /*
164 * We ignore I/O errors on directories so users have a chance
165 * of recovering data when there's a bad sector
166 */
167 if (!bh) {
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400168 if (!dir_has_error) {
Theodore Ts'of7c21172011-01-10 12:10:55 -0500169 EXT4_ERROR_FILE(filp, 0,
170 "directory contains a "
171 "hole at offset %llu",
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400172 (unsigned long long) filp->f_pos);
173 dir_has_error = 1;
174 }
Eric Sandeene6c40212006-12-06 20:36:28 -0800175 /* corrupt size? Maybe no more blocks to read */
176 if (filp->f_pos > inode->i_blocks << 9)
177 break;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700178 filp->f_pos += sb->s_blocksize - offset;
179 continue;
180 }
181
182revalidate:
183 /* If the dir block has changed since the last call to
184 * readdir(2), then we might be pointing to an invalid
185 * dirent right now. Scan from the start of the block
186 * to make sure. */
187 if (filp->f_version != inode->i_version) {
188 for (i = 0; i < sb->s_blocksize && i < offset; ) {
Mingming Cao617ba132006-10-11 01:20:53 -0700189 de = (struct ext4_dir_entry_2 *)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700190 (bh->b_data + i);
191 /* It's too expensive to do a full
192 * dirent test each time round this
193 * loop, but we do have to test at
194 * least that it is non-zero. A
195 * failure will be detected in the
196 * dirent test below. */
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500197 if (ext4_rec_len_from_disk(de->rec_len,
198 sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700199 break;
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500200 i += ext4_rec_len_from_disk(de->rec_len,
201 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700202 }
203 offset = i;
204 filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
205 | offset;
206 filp->f_version = inode->i_version;
207 }
208
209 while (!error && filp->f_pos < inode->i_size
210 && offset < sb->s_blocksize) {
Mingming Cao617ba132006-10-11 01:20:53 -0700211 de = (struct ext4_dir_entry_2 *) (bh->b_data + offset);
Theodore Ts'of7c21172011-01-10 12:10:55 -0500212 if (ext4_check_dir_entry(inode, filp, de,
Theodore Ts'ocad3f002010-12-19 22:07:02 -0500213 bh, offset)) {
Andrew Morton63f57932006-10-11 01:21:24 -0700214 /*
215 * On error, skip the f_pos to the next block
216 */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700217 filp->f_pos = (filp->f_pos |
218 (sb->s_blocksize - 1)) + 1;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400219 brelse(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700220 ret = stored;
221 goto out;
222 }
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500223 offset += ext4_rec_len_from_disk(de->rec_len,
224 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700225 if (le32_to_cpu(de->inode)) {
226 /* We might block in the next section
227 * if the data destination is
228 * currently swapped out. So, use a
229 * version stamp to detect whether or
230 * not the directory has been modified
231 * during the copy operation.
232 */
Mathieu Desnoyers2b47c362007-10-16 23:27:21 -0700233 u64 version = filp->f_version;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700234
235 error = filldir(dirent, de->name,
236 de->name_len,
237 filp->f_pos,
238 le32_to_cpu(de->inode),
239 get_dtype(sb, de->file_type));
240 if (error)
241 break;
242 if (version != filp->f_version)
243 goto revalidate;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400244 stored++;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700245 }
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500246 filp->f_pos += ext4_rec_len_from_disk(de->rec_len,
247 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700248 }
249 offset = 0;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400250 brelse(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700251 }
252out:
253 return ret;
254}
255
Fan Yongd1f52732012-03-18 22:44:40 -0400256static inline int is_32bit_api(void)
257{
258#ifdef CONFIG_COMPAT
259 return is_compat_task();
260#else
261 return (BITS_PER_LONG == 32);
262#endif
263}
264
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700265/*
266 * These functions convert from the major/minor hash to an f_pos
Fan Yongd1f52732012-03-18 22:44:40 -0400267 * value for dx directories
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700268 *
Fan Yongd1f52732012-03-18 22:44:40 -0400269 * Upper layer (for example NFS) should specify FMODE_32BITHASH or
270 * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted
271 * directly on both 32-bit and 64-bit nodes, under such case, neither
272 * FMODE_32BITHASH nor FMODE_64BITHASH is specified.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700273 */
Fan Yongd1f52732012-03-18 22:44:40 -0400274static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor)
275{
276 if ((filp->f_mode & FMODE_32BITHASH) ||
277 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
278 return major >> 1;
279 else
280 return ((__u64)(major >> 1) << 32) | (__u64)minor;
281}
282
283static inline __u32 pos2maj_hash(struct file *filp, loff_t pos)
284{
285 if ((filp->f_mode & FMODE_32BITHASH) ||
286 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
287 return (pos << 1) & 0xffffffff;
288 else
289 return ((pos >> 32) << 1) & 0xffffffff;
290}
291
292static inline __u32 pos2min_hash(struct file *filp, loff_t pos)
293{
294 if ((filp->f_mode & FMODE_32BITHASH) ||
295 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
296 return 0;
297 else
298 return pos & 0xffffffff;
299}
300
301/*
302 * Return 32- or 64-bit end-of-file for dx directories
303 */
304static inline loff_t ext4_get_htree_eof(struct file *filp)
305{
306 if ((filp->f_mode & FMODE_32BITHASH) ||
307 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
308 return EXT4_HTREE_EOF_32BIT;
309 else
310 return EXT4_HTREE_EOF_64BIT;
311}
312
313
314/*
315 * ext4_dir_llseek() based on generic_file_llseek() to handle both
316 * non-htree and htree directories, where the "offset" is in terms
317 * of the filename hash value instead of the byte offset.
318 *
319 * NOTE: offsets obtained *before* ext4_set_inode_flag(dir, EXT4_INODE_INDEX)
320 * will be invalid once the directory was converted into a dx directory
321 */
322loff_t ext4_dir_llseek(struct file *file, loff_t offset, int origin)
323{
324 struct inode *inode = file->f_mapping->host;
325 loff_t ret = -EINVAL;
326 int dx_dir = is_dx_dir(inode);
327
328 mutex_lock(&inode->i_mutex);
329
330 /* NOTE: relative offsets with dx directories might not work
331 * as expected, as it is difficult to figure out the
332 * correct offset between dx hashes */
333
334 switch (origin) {
335 case SEEK_END:
336 if (unlikely(offset > 0))
337 goto out_err; /* not supported for directories */
338
339 /* so only negative offsets are left, does that have a
340 * meaning for directories at all? */
341 if (dx_dir)
342 offset += ext4_get_htree_eof(file);
343 else
344 offset += inode->i_size;
345 break;
346 case SEEK_CUR:
347 /*
348 * Here we special-case the lseek(fd, 0, SEEK_CUR)
349 * position-querying operation. Avoid rewriting the "same"
350 * f_pos value back to the file because a concurrent read(),
351 * write() or lseek() might have altered it
352 */
353 if (offset == 0) {
354 offset = file->f_pos;
355 goto out_ok;
356 }
357
358 offset += file->f_pos;
359 break;
360 }
361
362 if (unlikely(offset < 0))
363 goto out_err;
364
365 if (!dx_dir) {
366 if (offset > inode->i_sb->s_maxbytes)
367 goto out_err;
368 } else if (offset > ext4_get_htree_eof(file))
369 goto out_err;
370
371 /* Special lock needed here? */
372 if (offset != file->f_pos) {
373 file->f_pos = offset;
374 file->f_version = 0;
375 }
376
377out_ok:
378 ret = offset;
379out_err:
380 mutex_unlock(&inode->i_mutex);
381
382 return ret;
383}
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700384
385/*
386 * This structure holds the nodes of the red-black tree used to store
387 * the directory entry in hash order.
388 */
389struct fname {
390 __u32 hash;
391 __u32 minor_hash;
392 struct rb_node rb_hash;
393 struct fname *next;
394 __u32 inode;
395 __u8 name_len;
396 __u8 file_type;
397 char name[0];
398};
399
400/*
401 * This functoin implements a non-recursive way of freeing all of the
402 * nodes in the red-black tree.
403 */
404static void free_rb_tree_fname(struct rb_root *root)
405{
406 struct rb_node *n = root->rb_node;
407 struct rb_node *parent;
408 struct fname *fname;
409
410 while (n) {
411 /* Do the node's children first */
Shen Feng69baee02008-07-11 19:27:31 -0400412 if (n->rb_left) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700413 n = n->rb_left;
414 continue;
415 }
416 if (n->rb_right) {
417 n = n->rb_right;
418 continue;
419 }
420 /*
421 * The node has no children; free it, and then zero
422 * out parent's link to it. Finally go to the
423 * beginning of the loop and try to free the parent
424 * node.
425 */
426 parent = rb_parent(n);
427 fname = rb_entry(n, struct fname, rb_hash);
428 while (fname) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400429 struct fname *old = fname;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700430 fname = fname->next;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400431 kfree(old);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700432 }
433 if (!parent)
Venkatesh Pallipadi64e290e2010-03-04 22:25:21 -0500434 *root = RB_ROOT;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700435 else if (parent->rb_left == n)
436 parent->rb_left = NULL;
437 else if (parent->rb_right == n)
438 parent->rb_right = NULL;
439 n = parent;
440 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700441}
442
443
Fan Yongd1f52732012-03-18 22:44:40 -0400444static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp,
445 loff_t pos)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700446{
447 struct dir_private_info *p;
448
Shen Feng69baee02008-07-11 19:27:31 -0400449 p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700450 if (!p)
451 return NULL;
Fan Yongd1f52732012-03-18 22:44:40 -0400452 p->curr_hash = pos2maj_hash(filp, pos);
453 p->curr_minor_hash = pos2min_hash(filp, pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700454 return p;
455}
456
Mingming Cao617ba132006-10-11 01:20:53 -0700457void ext4_htree_free_dir_info(struct dir_private_info *p)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700458{
459 free_rb_tree_fname(&p->root);
460 kfree(p);
461}
462
463/*
464 * Given a directory entry, enter it into the fname rb tree.
465 */
Mingming Cao617ba132006-10-11 01:20:53 -0700466int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700467 __u32 minor_hash,
Mingming Cao617ba132006-10-11 01:20:53 -0700468 struct ext4_dir_entry_2 *dirent)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700469{
470 struct rb_node **p, *parent = NULL;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400471 struct fname *fname, *new_fn;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700472 struct dir_private_info *info;
473 int len;
474
Joe Perchesa271fe82010-07-27 11:56:04 -0400475 info = dir_file->private_data;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700476 p = &info->root.rb_node;
477
478 /* Create and allocate the fname structure */
479 len = sizeof(struct fname) + dirent->name_len + 1;
480 new_fn = kzalloc(len, GFP_KERNEL);
481 if (!new_fn)
482 return -ENOMEM;
483 new_fn->hash = hash;
484 new_fn->minor_hash = minor_hash;
485 new_fn->inode = le32_to_cpu(dirent->inode);
486 new_fn->name_len = dirent->name_len;
487 new_fn->file_type = dirent->file_type;
488 memcpy(new_fn->name, dirent->name, dirent->name_len);
489 new_fn->name[dirent->name_len] = 0;
490
491 while (*p) {
492 parent = *p;
493 fname = rb_entry(parent, struct fname, rb_hash);
494
495 /*
496 * If the hash and minor hash match up, then we put
497 * them on a linked list. This rarely happens...
498 */
499 if ((new_fn->hash == fname->hash) &&
500 (new_fn->minor_hash == fname->minor_hash)) {
501 new_fn->next = fname->next;
502 fname->next = new_fn;
503 return 0;
504 }
505
506 if (new_fn->hash < fname->hash)
507 p = &(*p)->rb_left;
508 else if (new_fn->hash > fname->hash)
509 p = &(*p)->rb_right;
510 else if (new_fn->minor_hash < fname->minor_hash)
511 p = &(*p)->rb_left;
512 else /* if (new_fn->minor_hash > fname->minor_hash) */
513 p = &(*p)->rb_right;
514 }
515
516 rb_link_node(&new_fn->rb_hash, parent, p);
517 rb_insert_color(&new_fn->rb_hash, &info->root);
518 return 0;
519}
520
521
522
523/*
Mingming Cao617ba132006-10-11 01:20:53 -0700524 * This is a helper function for ext4_dx_readdir. It calls filldir
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700525 * for all entres on the fname linked list. (Normally there is only
526 * one entry on the linked list, unless there are 62 bit hash collisions.)
527 */
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400528static int call_filldir(struct file *filp, void *dirent,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700529 filldir_t filldir, struct fname *fname)
530{
531 struct dir_private_info *info = filp->private_data;
532 loff_t curr_pos;
Josef "Jeff" Sipek9d549892006-12-08 02:36:38 -0800533 struct inode *inode = filp->f_path.dentry->d_inode;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400534 struct super_block *sb;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700535 int error;
536
537 sb = inode->i_sb;
538
539 if (!fname) {
Theodore Ts'o92b97812012-03-19 23:41:49 -0400540 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: "
541 "called with null fname?!?", __func__, __LINE__,
542 inode->i_ino, current->comm);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700543 return 0;
544 }
Fan Yongd1f52732012-03-18 22:44:40 -0400545 curr_pos = hash2pos(filp, fname->hash, fname->minor_hash);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700546 while (fname) {
547 error = filldir(dirent, fname->name,
548 fname->name_len, curr_pos,
549 fname->inode,
550 get_dtype(sb, fname->file_type));
551 if (error) {
552 filp->f_pos = curr_pos;
Theodore Ts'od0156412008-08-19 21:57:43 -0400553 info->extra_fname = fname;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700554 return error;
555 }
556 fname = fname->next;
557 }
558 return 0;
559}
560
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400561static int ext4_dx_readdir(struct file *filp,
562 void *dirent, filldir_t filldir)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700563{
564 struct dir_private_info *info = filp->private_data;
Josef "Jeff" Sipek9d549892006-12-08 02:36:38 -0800565 struct inode *inode = filp->f_path.dentry->d_inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700566 struct fname *fname;
567 int ret;
568
569 if (!info) {
Fan Yongd1f52732012-03-18 22:44:40 -0400570 info = ext4_htree_create_dir_info(filp, filp->f_pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700571 if (!info)
572 return -ENOMEM;
573 filp->private_data = info;
574 }
575
Fan Yongd1f52732012-03-18 22:44:40 -0400576 if (filp->f_pos == ext4_get_htree_eof(filp))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700577 return 0; /* EOF */
578
579 /* Some one has messed with f_pos; reset the world */
580 if (info->last_pos != filp->f_pos) {
581 free_rb_tree_fname(&info->root);
582 info->curr_node = NULL;
583 info->extra_fname = NULL;
Fan Yongd1f52732012-03-18 22:44:40 -0400584 info->curr_hash = pos2maj_hash(filp, filp->f_pos);
585 info->curr_minor_hash = pos2min_hash(filp, filp->f_pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700586 }
587
588 /*
589 * If there are any leftover names on the hash collision
590 * chain, return them first.
591 */
Theodore Ts'od0156412008-08-19 21:57:43 -0400592 if (info->extra_fname) {
593 if (call_filldir(filp, dirent, filldir, info->extra_fname))
594 goto finished;
Theodore Ts'od0156412008-08-19 21:57:43 -0400595 info->extra_fname = NULL;
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400596 goto next_node;
Theodore Ts'od0156412008-08-19 21:57:43 -0400597 } else if (!info->curr_node)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700598 info->curr_node = rb_first(&info->root);
599
600 while (1) {
601 /*
602 * Fill the rbtree if we have no more entries,
603 * or the inode has changed since we last read in the
604 * cached entries.
605 */
606 if ((!info->curr_node) ||
607 (filp->f_version != inode->i_version)) {
608 info->curr_node = NULL;
609 free_rb_tree_fname(&info->root);
610 filp->f_version = inode->i_version;
Mingming Cao617ba132006-10-11 01:20:53 -0700611 ret = ext4_htree_fill_tree(filp, info->curr_hash,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700612 info->curr_minor_hash,
613 &info->next_hash);
614 if (ret < 0)
615 return ret;
616 if (ret == 0) {
Fan Yongd1f52732012-03-18 22:44:40 -0400617 filp->f_pos = ext4_get_htree_eof(filp);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700618 break;
619 }
620 info->curr_node = rb_first(&info->root);
621 }
622
623 fname = rb_entry(info->curr_node, struct fname, rb_hash);
624 info->curr_hash = fname->hash;
625 info->curr_minor_hash = fname->minor_hash;
626 if (call_filldir(filp, dirent, filldir, fname))
627 break;
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400628 next_node:
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700629 info->curr_node = rb_next(info->curr_node);
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400630 if (info->curr_node) {
631 fname = rb_entry(info->curr_node, struct fname,
632 rb_hash);
633 info->curr_hash = fname->hash;
634 info->curr_minor_hash = fname->minor_hash;
635 } else {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700636 if (info->next_hash == ~0) {
Fan Yongd1f52732012-03-18 22:44:40 -0400637 filp->f_pos = ext4_get_htree_eof(filp);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700638 break;
639 }
640 info->curr_hash = info->next_hash;
641 info->curr_minor_hash = 0;
642 }
643 }
644finished:
645 info->last_pos = filp->f_pos;
646 return 0;
647}
648
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400649static int ext4_release_dir(struct inode *inode, struct file *filp)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700650{
Andrew Morton63f57932006-10-11 01:21:24 -0700651 if (filp->private_data)
Mingming Cao617ba132006-10-11 01:20:53 -0700652 ext4_htree_free_dir_info(filp->private_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700653
654 return 0;
655}
Fan Yongd1f52732012-03-18 22:44:40 -0400656
657const struct file_operations ext4_dir_operations = {
658 .llseek = ext4_dir_llseek,
659 .read = generic_read_dir,
660 .readdir = ext4_readdir,
661 .unlocked_ioctl = ext4_ioctl,
662#ifdef CONFIG_COMPAT
663 .compat_ioctl = ext4_compat_ioctl,
664#endif
665 .fsync = ext4_sync_file,
666 .release = ext4_release_dir,
667};