blob: bafdd48eefde60a926e8f5478cf97a0ee2e1f598 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/ext3/dir.c
3 *
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 *
15 * ext3 directory handling functions
16 *
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
Eric Sandeend7dab392012-04-26 13:10:39 -050024#include <linux/compat.h>
Al Viro4613ad12012-03-29 22:30:07 -040025#include "ext3.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
27static unsigned char ext3_filetype_table[] = {
28 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
29};
30
Al Viro5ded75e2013-05-15 21:02:48 -040031static int ext3_dx_readdir(struct file *, struct dir_context *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33static unsigned char get_dtype(struct super_block *sb, int filetype)
34{
35 if (!EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_FILETYPE) ||
36 (filetype >= EXT3_FT_MAX))
37 return DT_UNKNOWN;
38
39 return (ext3_filetype_table[filetype]);
40}
Mingming Caoae6ddcc2006-09-27 01:49:27 -070041
Eric Sandeend7dab392012-04-26 13:10:39 -050042/**
43 * Check if the given dir-inode refers to an htree-indexed directory
Anatol Pomozov70261f52013-08-28 14:40:12 -040044 * (or a directory which could potentially get converted to use htree
Eric Sandeend7dab392012-04-26 13:10:39 -050045 * indexing).
46 *
47 * Return 1 if it is a dx dir, 0 if not
48 */
49static int is_dx_dir(struct inode *inode)
50{
51 struct super_block *sb = inode->i_sb;
52
53 if (EXT3_HAS_COMPAT_FEATURE(inode->i_sb,
54 EXT3_FEATURE_COMPAT_DIR_INDEX) &&
55 ((EXT3_I(inode)->i_flags & EXT3_INDEX_FL) ||
56 ((inode->i_size >> sb->s_blocksize_bits) == 1)))
57 return 1;
58
59 return 0;
60}
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
62int ext3_check_dir_entry (const char * function, struct inode * dir,
63 struct ext3_dir_entry_2 * de,
64 struct buffer_head * bh,
65 unsigned long offset)
66{
67 const char * error_msg = NULL;
Jan Kara7c06a8d2007-11-14 17:00:19 -080068 const int rlen = ext3_rec_len_from_disk(de->rec_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
Eric Sandeena4ae3092010-12-07 11:55:27 -060070 if (unlikely(rlen < EXT3_DIR_REC_LEN(1)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 error_msg = "rec_len is smaller than minimal";
Eric Sandeena4ae3092010-12-07 11:55:27 -060072 else if (unlikely(rlen % 4 != 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 error_msg = "rec_len % 4 != 0";
Eric Sandeena4ae3092010-12-07 11:55:27 -060074 else if (unlikely(rlen < EXT3_DIR_REC_LEN(de->name_len)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 error_msg = "rec_len is too small for name_len";
Eric Sandeena4ae3092010-12-07 11:55:27 -060076 else if (unlikely((((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 error_msg = "directory entry across blocks";
Eric Sandeena4ae3092010-12-07 11:55:27 -060078 else if (unlikely(le32_to_cpu(de->inode) >
79 le32_to_cpu(EXT3_SB(dir->i_sb)->s_es->s_inodes_count)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 error_msg = "inode out of bounds";
81
Eric Sandeena4ae3092010-12-07 11:55:27 -060082 if (unlikely(error_msg != NULL))
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 ext3_error (dir->i_sb, function,
84 "bad entry in directory #%lu: %s - "
85 "offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
86 dir->i_ino, error_msg, offset,
87 (unsigned long) le32_to_cpu(de->inode),
88 rlen, de->name_len);
Eric Sandeena4ae3092010-12-07 11:55:27 -060089
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 return error_msg == NULL ? 1 : 0;
91}
92
Al Viro5ded75e2013-05-15 21:02:48 -040093static int ext3_readdir(struct file *file, struct dir_context *ctx)
Linus Torvalds1da177e2005-04-16 15:20:36 -070094{
Andrew Mortond8733c22006-03-23 03:00:11 -080095 unsigned long offset;
Al Viro5ded75e2013-05-15 21:02:48 -040096 int i;
Andrew Mortond8733c22006-03-23 03:00:11 -080097 struct ext3_dir_entry_2 *de;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 int err;
Al Viro5ded75e2013-05-15 21:02:48 -040099 struct inode *inode = file_inode(file);
Eric Sandeend7dab392012-04-26 13:10:39 -0500100 struct super_block *sb = inode->i_sb;
Eric Sandeencdbf6db2008-10-18 20:28:00 -0700101 int dir_has_error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
Eric Sandeend7dab392012-04-26 13:10:39 -0500103 if (is_dx_dir(inode)) {
Al Viro5ded75e2013-05-15 21:02:48 -0400104 err = ext3_dx_readdir(file, ctx);
105 if (err != ERR_BAD_DX_DIR)
106 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 /*
108 * We don't set the inode dirty flag since it's not
109 * critical that it get flushed back to the disk.
110 */
Al Viro5ded75e2013-05-15 21:02:48 -0400111 EXT3_I(inode)->i_flags &= ~EXT3_INDEX_FL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 }
Al Viro5ded75e2013-05-15 21:02:48 -0400113 offset = ctx->pos & (sb->s_blocksize - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
Al Viro5ded75e2013-05-15 21:02:48 -0400115 while (ctx->pos < inode->i_size) {
116 unsigned long blk = ctx->pos >> EXT3_BLOCK_SIZE_BITS(sb);
Andrew Mortond8733c22006-03-23 03:00:11 -0800117 struct buffer_head map_bh;
118 struct buffer_head *bh = NULL;
119
120 map_bh.b_state = 0;
Jan Kara43237b52009-05-20 18:41:58 +0200121 err = ext3_get_blocks_handle(NULL, inode, blk, 1, &map_bh, 0);
Mingming Cao89747d32006-03-26 01:37:55 -0800122 if (err > 0) {
Fengguang Wudc7868f2007-07-19 01:48:04 -0700123 pgoff_t index = map_bh.b_blocknr >>
124 (PAGE_CACHE_SHIFT - inode->i_blkbits);
Al Viro5ded75e2013-05-15 21:02:48 -0400125 if (!ra_has_index(&file->f_ra, index))
Rusty Russellcf914a72007-07-19 01:48:08 -0700126 page_cache_sync_readahead(
Fengguang Wudc7868f2007-07-19 01:48:04 -0700127 sb->s_bdev->bd_inode->i_mapping,
Al Viro5ded75e2013-05-15 21:02:48 -0400128 &file->f_ra, file,
Rusty Russellcf914a72007-07-19 01:48:08 -0700129 index, 1);
Al Viro5ded75e2013-05-15 21:02:48 -0400130 file->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
Andrew Mortond8733c22006-03-23 03:00:11 -0800131 bh = ext3_bread(NULL, inode, blk, 0, &err);
132 }
133
134 /*
135 * We ignore I/O errors on directories so users have a chance
136 * of recovering data when there's a bad sector
137 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 if (!bh) {
Eric Sandeencdbf6db2008-10-18 20:28:00 -0700139 if (!dir_has_error) {
140 ext3_error(sb, __func__, "directory #%lu "
141 "contains a hole at offset %lld",
Al Viro5ded75e2013-05-15 21:02:48 -0400142 inode->i_ino, ctx->pos);
Eric Sandeencdbf6db2008-10-18 20:28:00 -0700143 dir_has_error = 1;
144 }
Eric Sandeen40b85132006-12-06 20:36:26 -0800145 /* corrupt size? Maybe no more blocks to read */
Al Viro5ded75e2013-05-15 21:02:48 -0400146 if (ctx->pos > inode->i_blocks << 9)
Eric Sandeen40b85132006-12-06 20:36:26 -0800147 break;
Al Viro5ded75e2013-05-15 21:02:48 -0400148 ctx->pos += sb->s_blocksize - offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 continue;
150 }
151
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 /* If the dir block has changed since the last call to
153 * readdir(2), then we might be pointing to an invalid
154 * dirent right now. Scan from the start of the block
155 * to make sure. */
Al Viro5ded75e2013-05-15 21:02:48 -0400156 if (offset && file->f_version != inode->i_version) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 for (i = 0; i < sb->s_blocksize && i < offset; ) {
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700158 de = (struct ext3_dir_entry_2 *)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 (bh->b_data + i);
160 /* It's too expensive to do a full
161 * dirent test each time round this
162 * loop, but we do have to test at
163 * least that it is non-zero. A
164 * failure will be detected in the
165 * dirent test below. */
Jan Kara7c06a8d2007-11-14 17:00:19 -0800166 if (ext3_rec_len_from_disk(de->rec_len) <
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 EXT3_DIR_REC_LEN(1))
168 break;
Jan Kara7c06a8d2007-11-14 17:00:19 -0800169 i += ext3_rec_len_from_disk(de->rec_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 }
171 offset = i;
Al Viro5ded75e2013-05-15 21:02:48 -0400172 ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 | offset;
Al Viro5ded75e2013-05-15 21:02:48 -0400174 file->f_version = inode->i_version;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 }
176
Al Viro5ded75e2013-05-15 21:02:48 -0400177 while (ctx->pos < inode->i_size
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 && offset < sb->s_blocksize) {
179 de = (struct ext3_dir_entry_2 *) (bh->b_data + offset);
180 if (!ext3_check_dir_entry ("ext3_readdir", inode, de,
181 bh, offset)) {
Al Viro5ded75e2013-05-15 21:02:48 -0400182 /* On error, skip the to the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 next block. */
Al Viro5ded75e2013-05-15 21:02:48 -0400184 ctx->pos = (ctx->pos |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 (sb->s_blocksize - 1)) + 1;
Al Viro5ded75e2013-05-15 21:02:48 -0400186 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 }
Jan Kara7c06a8d2007-11-14 17:00:19 -0800188 offset += ext3_rec_len_from_disk(de->rec_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 if (le32_to_cpu(de->inode)) {
Al Viro5ded75e2013-05-15 21:02:48 -0400190 if (!dir_emit(ctx, de->name, de->name_len,
191 le32_to_cpu(de->inode),
192 get_dtype(sb, de->file_type))) {
193 brelse(bh);
194 return 0;
195 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 }
Al Viro5ded75e2013-05-15 21:02:48 -0400197 ctx->pos += ext3_rec_len_from_disk(de->rec_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 }
199 offset = 0;
200 brelse (bh);
Al Viro5ded75e2013-05-15 21:02:48 -0400201 if (ctx->pos < inode->i_size)
202 if (!dir_relax(inode))
203 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 }
Al Viro5ded75e2013-05-15 21:02:48 -0400205 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206}
207
Eric Sandeend7dab392012-04-26 13:10:39 -0500208static inline int is_32bit_api(void)
209{
210#ifdef CONFIG_COMPAT
211 return is_compat_task();
212#else
213 return (BITS_PER_LONG == 32);
214#endif
215}
216
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217/*
218 * These functions convert from the major/minor hash to an f_pos
Eric Sandeend7dab392012-04-26 13:10:39 -0500219 * value for dx directories
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700220 *
Eric Sandeend7dab392012-04-26 13:10:39 -0500221 * Upper layer (for example NFS) should specify FMODE_32BITHASH or
222 * FMODE_64BITHASH explicitly. On the other hand, we allow ext3 to be mounted
223 * directly on both 32-bit and 64-bit nodes, under such case, neither
224 * FMODE_32BITHASH nor FMODE_64BITHASH is specified.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 */
Eric Sandeend7dab392012-04-26 13:10:39 -0500226static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor)
227{
228 if ((filp->f_mode & FMODE_32BITHASH) ||
229 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
230 return major >> 1;
231 else
232 return ((__u64)(major >> 1) << 32) | (__u64)minor;
233}
234
235static inline __u32 pos2maj_hash(struct file *filp, loff_t pos)
236{
237 if ((filp->f_mode & FMODE_32BITHASH) ||
238 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
239 return (pos << 1) & 0xffffffff;
240 else
241 return ((pos >> 32) << 1) & 0xffffffff;
242}
243
244static inline __u32 pos2min_hash(struct file *filp, loff_t pos)
245{
246 if ((filp->f_mode & FMODE_32BITHASH) ||
247 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
248 return 0;
249 else
250 return pos & 0xffffffff;
251}
252
253/*
254 * Return 32- or 64-bit end-of-file for dx directories
255 */
256static inline loff_t ext3_get_htree_eof(struct file *filp)
257{
258 if ((filp->f_mode & FMODE_32BITHASH) ||
259 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
260 return EXT3_HTREE_EOF_32BIT;
261 else
262 return EXT3_HTREE_EOF_64BIT;
263}
264
265
266/*
267 * ext3_dir_llseek() calls generic_file_llseek[_size]() to handle both
268 * non-htree and htree directories, where the "offset" is in terms
269 * of the filename hash value instead of the byte offset.
270 *
271 * Because we may return a 64-bit hash that is well beyond s_maxbytes,
272 * we need to pass the max hash as the maximum allowable offset in
273 * the htree directory case.
274 *
275 * NOTE: offsets obtained *before* ext3_set_inode_flag(dir, EXT3_INODE_INDEX)
276 * will be invalid once the directory was converted into a dx directory
277 */
Andrew Morton965c8e52012-12-17 15:59:39 -0800278loff_t ext3_dir_llseek(struct file *file, loff_t offset, int whence)
Eric Sandeend7dab392012-04-26 13:10:39 -0500279{
280 struct inode *inode = file->f_mapping->host;
281 int dx_dir = is_dx_dir(inode);
Eric Sandeende9b9422012-04-30 13:16:04 -0500282 loff_t htree_max = ext3_get_htree_eof(file);
Eric Sandeend7dab392012-04-26 13:10:39 -0500283
284 if (likely(dx_dir))
Andrew Morton965c8e52012-12-17 15:59:39 -0800285 return generic_file_llseek_size(file, offset, whence,
Eric Sandeende9b9422012-04-30 13:16:04 -0500286 htree_max, htree_max);
Eric Sandeend7dab392012-04-26 13:10:39 -0500287 else
Andrew Morton965c8e52012-12-17 15:59:39 -0800288 return generic_file_llseek(file, offset, whence);
Eric Sandeend7dab392012-04-26 13:10:39 -0500289}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290
291/*
292 * This structure holds the nodes of the red-black tree used to store
293 * the directory entry in hash order.
294 */
295struct fname {
296 __u32 hash;
297 __u32 minor_hash;
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700298 struct rb_node rb_hash;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 struct fname *next;
300 __u32 inode;
301 __u8 name_len;
302 __u8 file_type;
303 char name[0];
304};
305
306/*
307 * This functoin implements a non-recursive way of freeing all of the
308 * nodes in the red-black tree.
309 */
310static void free_rb_tree_fname(struct rb_root *root)
311{
312 struct rb_node *n = root->rb_node;
313 struct rb_node *parent;
314 struct fname *fname;
315
316 while (n) {
317 /* Do the node's children first */
Shen Feng9ebfbe92008-07-25 01:46:21 -0700318 if (n->rb_left) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 n = n->rb_left;
320 continue;
321 }
322 if (n->rb_right) {
323 n = n->rb_right;
324 continue;
325 }
326 /*
327 * The node has no children; free it, and then zero
328 * out parent's link to it. Finally go to the
329 * beginning of the loop and try to free the parent
330 * node.
331 */
David Woodhouse52b51082006-04-21 13:15:57 +0100332 parent = rb_parent(n);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 fname = rb_entry(n, struct fname, rb_hash);
334 while (fname) {
335 struct fname * old = fname;
336 fname = fname->next;
337 kfree (old);
338 }
339 if (!parent)
Venkatesh Pallipadi1513b022010-05-25 16:03:04 +0200340 *root = RB_ROOT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 else if (parent->rb_left == n)
342 parent->rb_left = NULL;
343 else if (parent->rb_right == n)
344 parent->rb_right = NULL;
345 n = parent;
346 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347}
348
349
Eric Sandeend7dab392012-04-26 13:10:39 -0500350static struct dir_private_info *ext3_htree_create_dir_info(struct file *filp,
351 loff_t pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352{
353 struct dir_private_info *p;
354
Shen Feng9ebfbe92008-07-25 01:46:21 -0700355 p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 if (!p)
357 return NULL;
Eric Sandeend7dab392012-04-26 13:10:39 -0500358 p->curr_hash = pos2maj_hash(filp, pos);
359 p->curr_minor_hash = pos2min_hash(filp, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 return p;
361}
362
363void ext3_htree_free_dir_info(struct dir_private_info *p)
364{
365 free_rb_tree_fname(&p->root);
366 kfree(p);
367}
368
369/*
370 * Given a directory entry, enter it into the fname rb tree.
371 */
372int ext3_htree_store_dirent(struct file *dir_file, __u32 hash,
373 __u32 minor_hash,
374 struct ext3_dir_entry_2 *dirent)
375{
376 struct rb_node **p, *parent = NULL;
377 struct fname * fname, *new_fn;
378 struct dir_private_info *info;
379 int len;
380
381 info = (struct dir_private_info *) dir_file->private_data;
382 p = &info->root.rb_node;
383
384 /* Create and allocate the fname structure */
385 len = sizeof(struct fname) + dirent->name_len + 1;
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -0700386 new_fn = kzalloc(len, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 if (!new_fn)
388 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 new_fn->hash = hash;
390 new_fn->minor_hash = minor_hash;
391 new_fn->inode = le32_to_cpu(dirent->inode);
392 new_fn->name_len = dirent->name_len;
393 new_fn->file_type = dirent->file_type;
394 memcpy(new_fn->name, dirent->name, dirent->name_len);
395 new_fn->name[dirent->name_len] = 0;
396
397 while (*p) {
398 parent = *p;
399 fname = rb_entry(parent, struct fname, rb_hash);
400
401 /*
402 * If the hash and minor hash match up, then we put
403 * them on a linked list. This rarely happens...
404 */
405 if ((new_fn->hash == fname->hash) &&
406 (new_fn->minor_hash == fname->minor_hash)) {
407 new_fn->next = fname->next;
408 fname->next = new_fn;
409 return 0;
410 }
411
412 if (new_fn->hash < fname->hash)
413 p = &(*p)->rb_left;
414 else if (new_fn->hash > fname->hash)
415 p = &(*p)->rb_right;
416 else if (new_fn->minor_hash < fname->minor_hash)
417 p = &(*p)->rb_left;
418 else /* if (new_fn->minor_hash > fname->minor_hash) */
419 p = &(*p)->rb_right;
420 }
421
422 rb_link_node(&new_fn->rb_hash, parent, p);
423 rb_insert_color(&new_fn->rb_hash, &info->root);
424 return 0;
425}
426
427
428
429/*
430 * This is a helper function for ext3_dx_readdir. It calls filldir
431 * for all entres on the fname linked list. (Normally there is only
432 * one entry on the linked list, unless there are 62 bit hash collisions.)
433 */
Al Viro5ded75e2013-05-15 21:02:48 -0400434static bool call_filldir(struct file *file, struct dir_context *ctx,
435 struct fname *fname)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436{
Al Viro5ded75e2013-05-15 21:02:48 -0400437 struct dir_private_info *info = file->private_data;
438 struct inode *inode = file_inode(file);
439 struct super_block *sb = inode->i_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440
441 if (!fname) {
442 printk("call_filldir: called with null fname?!?\n");
Al Viro5ded75e2013-05-15 21:02:48 -0400443 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 }
Al Viro5ded75e2013-05-15 21:02:48 -0400445 ctx->pos = hash2pos(file, fname->hash, fname->minor_hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 while (fname) {
Al Viro5ded75e2013-05-15 21:02:48 -0400447 if (!dir_emit(ctx, fname->name, fname->name_len,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 fname->inode,
Al Viro5ded75e2013-05-15 21:02:48 -0400449 get_dtype(sb, fname->file_type))) {
Eugene Dashevsky6a897cf2008-10-18 20:27:59 -0700450 info->extra_fname = fname;
Al Viro5ded75e2013-05-15 21:02:48 -0400451 return false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 }
453 fname = fname->next;
454 }
Al Viro5ded75e2013-05-15 21:02:48 -0400455 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456}
457
Al Viro5ded75e2013-05-15 21:02:48 -0400458static int ext3_dx_readdir(struct file *file, struct dir_context *ctx)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459{
Al Viro5ded75e2013-05-15 21:02:48 -0400460 struct dir_private_info *info = file->private_data;
461 struct inode *inode = file_inode(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 struct fname *fname;
463 int ret;
464
465 if (!info) {
Al Viro5ded75e2013-05-15 21:02:48 -0400466 info = ext3_htree_create_dir_info(file, ctx->pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 if (!info)
468 return -ENOMEM;
Al Viro5ded75e2013-05-15 21:02:48 -0400469 file->private_data = info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 }
471
Al Viro5ded75e2013-05-15 21:02:48 -0400472 if (ctx->pos == ext3_get_htree_eof(file))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473 return 0; /* EOF */
474
475 /* Some one has messed with f_pos; reset the world */
Al Viro5ded75e2013-05-15 21:02:48 -0400476 if (info->last_pos != ctx->pos) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 free_rb_tree_fname(&info->root);
478 info->curr_node = NULL;
479 info->extra_fname = NULL;
Al Viro5ded75e2013-05-15 21:02:48 -0400480 info->curr_hash = pos2maj_hash(file, ctx->pos);
481 info->curr_minor_hash = pos2min_hash(file, ctx->pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 }
483
484 /*
485 * If there are any leftover names on the hash collision
486 * chain, return them first.
487 */
Eugene Dashevsky6a897cf2008-10-18 20:27:59 -0700488 if (info->extra_fname) {
Al Viro5ded75e2013-05-15 21:02:48 -0400489 if (!call_filldir(file, ctx, info->extra_fname))
Eugene Dashevsky6a897cf2008-10-18 20:27:59 -0700490 goto finished;
Eugene Dashevsky6a897cf2008-10-18 20:27:59 -0700491 info->extra_fname = NULL;
Theodore Ts'o8c9fa932008-10-25 11:38:37 -0400492 goto next_node;
Eugene Dashevsky6a897cf2008-10-18 20:27:59 -0700493 } else if (!info->curr_node)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 info->curr_node = rb_first(&info->root);
495
496 while (1) {
497 /*
498 * Fill the rbtree if we have no more entries,
499 * or the inode has changed since we last read in the
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700500 * cached entries.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 */
502 if ((!info->curr_node) ||
Al Viro5ded75e2013-05-15 21:02:48 -0400503 (file->f_version != inode->i_version)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 info->curr_node = NULL;
505 free_rb_tree_fname(&info->root);
Al Viro5ded75e2013-05-15 21:02:48 -0400506 file->f_version = inode->i_version;
507 ret = ext3_htree_fill_tree(file, info->curr_hash,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 info->curr_minor_hash,
509 &info->next_hash);
510 if (ret < 0)
511 return ret;
512 if (ret == 0) {
Al Viro5ded75e2013-05-15 21:02:48 -0400513 ctx->pos = ext3_get_htree_eof(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 break;
515 }
516 info->curr_node = rb_first(&info->root);
517 }
518
519 fname = rb_entry(info->curr_node, struct fname, rb_hash);
520 info->curr_hash = fname->hash;
521 info->curr_minor_hash = fname->minor_hash;
Al Viro5ded75e2013-05-15 21:02:48 -0400522 if (!call_filldir(file, ctx, fname))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 break;
Theodore Ts'o8c9fa932008-10-25 11:38:37 -0400524 next_node:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 info->curr_node = rb_next(info->curr_node);
Theodore Ts'o8c9fa932008-10-25 11:38:37 -0400526 if (info->curr_node) {
527 fname = rb_entry(info->curr_node, struct fname,
528 rb_hash);
529 info->curr_hash = fname->hash;
530 info->curr_minor_hash = fname->minor_hash;
531 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 if (info->next_hash == ~0) {
Al Viro5ded75e2013-05-15 21:02:48 -0400533 ctx->pos = ext3_get_htree_eof(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 break;
535 }
536 info->curr_hash = info->next_hash;
537 info->curr_minor_hash = 0;
538 }
539 }
540finished:
Al Viro5ded75e2013-05-15 21:02:48 -0400541 info->last_pos = ctx->pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 return 0;
543}
544
545static int ext3_release_dir (struct inode * inode, struct file * filp)
546{
547 if (filp->private_data)
548 ext3_htree_free_dir_info(filp->private_data);
549
550 return 0;
551}
Eric Sandeend7dab392012-04-26 13:10:39 -0500552
553const struct file_operations ext3_dir_operations = {
554 .llseek = ext3_dir_llseek,
555 .read = generic_read_dir,
Al Viro5ded75e2013-05-15 21:02:48 -0400556 .iterate = ext3_readdir,
Eric Sandeend7dab392012-04-26 13:10:39 -0500557 .unlocked_ioctl = ext3_ioctl,
558#ifdef CONFIG_COMPAT
559 .compat_ioctl = ext3_compat_ioctl,
560#endif
561 .fsync = ext3_sync_file,
562 .release = ext3_release_dir,
563};