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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"
Tao Ma65d165d2012-12-10 14:05:59 -050030#include "xattr.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070031
Al Viro725bebb2013-05-17 16:08:53 -040032static int ext4_dx_readdir(struct file *, struct dir_context *);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070033
Fan Yongd1f52732012-03-18 22:44:40 -040034/**
35 * Check if the given dir-inode refers to an htree-indexed directory
Anatol Pomozov70261f52013-08-28 14:40:12 -040036 * (or a directory which could potentially get converted to use htree
Fan Yongd1f52732012-03-18 22:44:40 -040037 * indexing).
38 *
39 * Return 1 if it is a dx dir, 0 if not
40 */
41static int is_dx_dir(struct inode *inode)
42{
43 struct super_block *sb = inode->i_sb;
44
45 if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
46 EXT4_FEATURE_COMPAT_DIR_INDEX) &&
47 ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) ||
Tao Ma8af0f082013-04-19 17:53:09 -040048 ((inode->i_size >> sb->s_blocksize_bits) == 1) ||
49 ext4_has_inline_data(inode)))
Fan Yongd1f52732012-03-18 22:44:40 -040050 return 1;
51
52 return 0;
53}
54
Theodore Ts'ocad3f002010-12-19 22:07:02 -050055/*
56 * Return 0 if the directory entry is OK, and 1 if there is a problem
57 *
58 * Note: this is the opposite of what ext2 and ext3 historically returned...
Tao Ma65d165d2012-12-10 14:05:59 -050059 *
60 * bh passed here can be an inode block or a dir data block, depending
61 * on the inode inline data flag.
Theodore Ts'ocad3f002010-12-19 22:07:02 -050062 */
Theodore Ts'o60fd4da2010-07-27 11:54:40 -040063int __ext4_check_dir_entry(const char *function, unsigned int line,
Theodore Ts'of7c21172011-01-10 12:10:55 -050064 struct inode *dir, struct file *filp,
Theodore Ts'o60fd4da2010-07-27 11:54:40 -040065 struct ext4_dir_entry_2 *de,
Tao Ma226ba972012-12-10 14:05:58 -050066 struct buffer_head *bh, char *buf, int size,
Theodore Ts'o60fd4da2010-07-27 11:54:40 -040067 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
Theodore Ts'ocad3f002010-12-19 22:07:02 -050073 if (unlikely(rlen < EXT4_DIR_REC_LEN(1)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070074 error_msg = "rec_len is smaller than minimal";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050075 else if (unlikely(rlen % 4 != 0))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070076 error_msg = "rec_len % 4 != 0";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050077 else if (unlikely(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";
Tao Ma226ba972012-12-10 14:05:58 -050079 else if (unlikely(((char *) de - buf) + rlen > size))
80 error_msg = "directory entry across range";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050081 else if (unlikely(le32_to_cpu(de->inode) >
82 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";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050084 else
85 return 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070086
Theodore Ts'of7c21172011-01-10 12:10:55 -050087 if (filp)
Dan Carpenter4fda4002012-02-20 17:53:05 -050088 ext4_error_file(filp, function, line, bh->b_blocknr,
Theodore Ts'of7c21172011-01-10 12:10:55 -050089 "bad entry in directory: %s - offset=%u(%u), "
90 "inode=%u, rec_len=%d, name_len=%d",
Tao Ma226ba972012-12-10 14:05:58 -050091 error_msg, (unsigned) (offset % size),
Theodore Ts'of7c21172011-01-10 12:10:55 -050092 offset, le32_to_cpu(de->inode),
93 rlen, de->name_len);
94 else
Dan Carpenter4fda4002012-02-20 17:53:05 -050095 ext4_error_inode(dir, function, line, bh->b_blocknr,
Theodore Ts'of7c21172011-01-10 12:10:55 -050096 "bad entry in directory: %s - offset=%u(%u), "
97 "inode=%u, rec_len=%d, name_len=%d",
Tao Ma226ba972012-12-10 14:05:58 -050098 error_msg, (unsigned) (offset % size),
Theodore Ts'of7c21172011-01-10 12:10:55 -050099 offset, le32_to_cpu(de->inode),
100 rlen, de->name_len);
101
Theodore Ts'ocad3f002010-12-19 22:07:02 -0500102 return 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700103}
104
Al Viro725bebb2013-05-17 16:08:53 -0400105static int ext4_readdir(struct file *file, struct dir_context *ctx)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700106{
Theodore Ts'o498e5f22008-11-05 00:14:04 -0500107 unsigned int offset;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700108 int i, stored;
Mingming Cao617ba132006-10-11 01:20:53 -0700109 struct ext4_dir_entry_2 *de;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700110 int err;
Al Viro725bebb2013-05-17 16:08:53 -0400111 struct inode *inode = file_inode(file);
Fan Yongd1f52732012-03-18 22:44:40 -0400112 struct super_block *sb = inode->i_sb;
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400113 int dir_has_error = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700114
Fan Yongd1f52732012-03-18 22:44:40 -0400115 if (is_dx_dir(inode)) {
Al Viro725bebb2013-05-17 16:08:53 -0400116 err = ext4_dx_readdir(file, ctx);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700117 if (err != ERR_BAD_DX_DIR) {
Al Viro725bebb2013-05-17 16:08:53 -0400118 return err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700119 }
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 */
Al Viro725bebb2013-05-17 16:08:53 -0400124 ext4_clear_inode_flag(file_inode(file),
Theodore Ts'o07a03822010-06-14 09:54:48 -0400125 EXT4_INODE_INDEX);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700126 }
Tao Ma8af0f082013-04-19 17:53:09 -0400127
128 if (ext4_has_inline_data(inode)) {
129 int has_inline_data = 1;
Al Viro725bebb2013-05-17 16:08:53 -0400130 int ret = ext4_read_inline_dir(file, ctx,
Tao Ma8af0f082013-04-19 17:53:09 -0400131 &has_inline_data);
132 if (has_inline_data)
133 return ret;
134 }
135
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700136 stored = 0;
Al Viro725bebb2013-05-17 16:08:53 -0400137 offset = ctx->pos & (sb->s_blocksize - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700138
Al Viro725bebb2013-05-17 16:08:53 -0400139 while (ctx->pos < inode->i_size) {
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400140 struct ext4_map_blocks map;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700141 struct buffer_head *bh = NULL;
142
Al Viro725bebb2013-05-17 16:08:53 -0400143 map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb);
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400144 map.m_len = 1;
145 err = ext4_map_blocks(NULL, inode, &map, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700146 if (err > 0) {
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400147 pgoff_t index = map.m_pblk >>
Fengguang Wudc7868f2007-07-19 01:48:04 -0700148 (PAGE_CACHE_SHIFT - inode->i_blkbits);
Al Viro725bebb2013-05-17 16:08:53 -0400149 if (!ra_has_index(&file->f_ra, index))
Rusty Russellcf914a72007-07-19 01:48:08 -0700150 page_cache_sync_readahead(
Fengguang Wudc7868f2007-07-19 01:48:04 -0700151 sb->s_bdev->bd_inode->i_mapping,
Al Viro725bebb2013-05-17 16:08:53 -0400152 &file->f_ra, file,
Rusty Russellcf914a72007-07-19 01:48:08 -0700153 index, 1);
Al Viro725bebb2013-05-17 16:08:53 -0400154 file->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400155 bh = ext4_bread(NULL, inode, map.m_lblk, 0, &err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700156 }
157
158 /*
159 * We ignore I/O errors on directories so users have a chance
160 * of recovering data when there's a bad sector
161 */
162 if (!bh) {
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400163 if (!dir_has_error) {
Al Viro725bebb2013-05-17 16:08:53 -0400164 EXT4_ERROR_FILE(file, 0,
Theodore Ts'of7c21172011-01-10 12:10:55 -0500165 "directory contains a "
166 "hole at offset %llu",
Al Viro725bebb2013-05-17 16:08:53 -0400167 (unsigned long long) ctx->pos);
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400168 dir_has_error = 1;
169 }
Eric Sandeene6c40212006-12-06 20:36:28 -0800170 /* corrupt size? Maybe no more blocks to read */
Al Viro725bebb2013-05-17 16:08:53 -0400171 if (ctx->pos > inode->i_blocks << 9)
Eric Sandeene6c40212006-12-06 20:36:28 -0800172 break;
Al Viro725bebb2013-05-17 16:08:53 -0400173 ctx->pos += sb->s_blocksize - offset;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700174 continue;
175 }
176
Darrick J. Wongb0336e82012-04-29 18:41:10 -0400177 /* Check the checksum */
178 if (!buffer_verified(bh) &&
179 !ext4_dirent_csum_verify(inode,
180 (struct ext4_dir_entry *)bh->b_data)) {
Al Viro725bebb2013-05-17 16:08:53 -0400181 EXT4_ERROR_FILE(file, 0, "directory fails checksum "
Darrick J. Wongb0336e82012-04-29 18:41:10 -0400182 "at offset %llu",
Al Viro725bebb2013-05-17 16:08:53 -0400183 (unsigned long long)ctx->pos);
184 ctx->pos += sb->s_blocksize - offset;
Guo Chaod5ac7772013-01-28 21:23:24 -0500185 brelse(bh);
Darrick J. Wongb0336e82012-04-29 18:41:10 -0400186 continue;
187 }
188 set_buffer_verified(bh);
189
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700190 /* If the dir block has changed since the last call to
191 * readdir(2), then we might be pointing to an invalid
192 * dirent right now. Scan from the start of the block
193 * to make sure. */
Al Viro725bebb2013-05-17 16:08:53 -0400194 if (file->f_version != inode->i_version) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700195 for (i = 0; i < sb->s_blocksize && i < offset; ) {
Mingming Cao617ba132006-10-11 01:20:53 -0700196 de = (struct ext4_dir_entry_2 *)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700197 (bh->b_data + i);
198 /* It's too expensive to do a full
199 * dirent test each time round this
200 * loop, but we do have to test at
201 * least that it is non-zero. A
202 * failure will be detected in the
203 * dirent test below. */
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500204 if (ext4_rec_len_from_disk(de->rec_len,
205 sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700206 break;
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500207 i += ext4_rec_len_from_disk(de->rec_len,
208 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700209 }
210 offset = i;
Al Viro725bebb2013-05-17 16:08:53 -0400211 ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700212 | offset;
Al Viro725bebb2013-05-17 16:08:53 -0400213 file->f_version = inode->i_version;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700214 }
215
Al Viro725bebb2013-05-17 16:08:53 -0400216 while (ctx->pos < inode->i_size
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700217 && offset < sb->s_blocksize) {
Mingming Cao617ba132006-10-11 01:20:53 -0700218 de = (struct ext4_dir_entry_2 *) (bh->b_data + offset);
Al Viro725bebb2013-05-17 16:08:53 -0400219 if (ext4_check_dir_entry(inode, file, de, bh,
Tao Ma226ba972012-12-10 14:05:58 -0500220 bh->b_data, bh->b_size,
221 offset)) {
Andrew Morton63f57932006-10-11 01:21:24 -0700222 /*
Al Viro725bebb2013-05-17 16:08:53 -0400223 * On error, skip to the next block
Andrew Morton63f57932006-10-11 01:21:24 -0700224 */
Al Viro725bebb2013-05-17 16:08:53 -0400225 ctx->pos = (ctx->pos |
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700226 (sb->s_blocksize - 1)) + 1;
Al Viro725bebb2013-05-17 16:08:53 -0400227 break;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700228 }
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500229 offset += ext4_rec_len_from_disk(de->rec_len,
230 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700231 if (le32_to_cpu(de->inode)) {
Al Viro725bebb2013-05-17 16:08:53 -0400232 if (!dir_emit(ctx, de->name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700233 de->name_len,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700234 le32_to_cpu(de->inode),
Al Viro725bebb2013-05-17 16:08:53 -0400235 get_dtype(sb, de->file_type))) {
236 brelse(bh);
237 return 0;
238 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700239 }
Al Viro725bebb2013-05-17 16:08:53 -0400240 ctx->pos += ext4_rec_len_from_disk(de->rec_len,
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500241 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700242 }
243 offset = 0;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400244 brelse(bh);
Al Viro725bebb2013-05-17 16:08:53 -0400245 if (ctx->pos < inode->i_size) {
246 if (!dir_relax(inode))
247 return 0;
248 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700249 }
Al Viro725bebb2013-05-17 16:08:53 -0400250 return 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700251}
252
Fan Yongd1f52732012-03-18 22:44:40 -0400253static inline int is_32bit_api(void)
254{
255#ifdef CONFIG_COMPAT
256 return is_compat_task();
257#else
258 return (BITS_PER_LONG == 32);
259#endif
260}
261
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700262/*
263 * These functions convert from the major/minor hash to an f_pos
Fan Yongd1f52732012-03-18 22:44:40 -0400264 * value for dx directories
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700265 *
Fan Yongd1f52732012-03-18 22:44:40 -0400266 * Upper layer (for example NFS) should specify FMODE_32BITHASH or
267 * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted
268 * directly on both 32-bit and 64-bit nodes, under such case, neither
269 * FMODE_32BITHASH nor FMODE_64BITHASH is specified.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700270 */
Fan Yongd1f52732012-03-18 22:44:40 -0400271static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor)
272{
273 if ((filp->f_mode & FMODE_32BITHASH) ||
274 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
275 return major >> 1;
276 else
277 return ((__u64)(major >> 1) << 32) | (__u64)minor;
278}
279
280static inline __u32 pos2maj_hash(struct file *filp, loff_t pos)
281{
282 if ((filp->f_mode & FMODE_32BITHASH) ||
283 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
284 return (pos << 1) & 0xffffffff;
285 else
286 return ((pos >> 32) << 1) & 0xffffffff;
287}
288
289static inline __u32 pos2min_hash(struct file *filp, loff_t pos)
290{
291 if ((filp->f_mode & FMODE_32BITHASH) ||
292 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
293 return 0;
294 else
295 return pos & 0xffffffff;
296}
297
298/*
299 * Return 32- or 64-bit end-of-file for dx directories
300 */
301static inline loff_t ext4_get_htree_eof(struct file *filp)
302{
303 if ((filp->f_mode & FMODE_32BITHASH) ||
304 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
305 return EXT4_HTREE_EOF_32BIT;
306 else
307 return EXT4_HTREE_EOF_64BIT;
308}
309
310
311/*
Eric Sandeenec7268c2012-04-30 13:14:03 -0500312 * ext4_dir_llseek() calls generic_file_llseek_size to handle htree
313 * directories, where the "offset" is in terms of the filename hash
314 * value instead of the byte offset.
Fan Yongd1f52732012-03-18 22:44:40 -0400315 *
Eric Sandeenec7268c2012-04-30 13:14:03 -0500316 * Because we may return a 64-bit hash that is well beyond offset limits,
317 * we need to pass the max hash as the maximum allowable offset in
318 * the htree directory case.
319 *
320 * For non-htree, ext4_llseek already chooses the proper max offset.
Fan Yongd1f52732012-03-18 22:44:40 -0400321 */
Zheng Liud4e43952013-03-02 17:24:05 -0500322static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence)
Fan Yongd1f52732012-03-18 22:44:40 -0400323{
324 struct inode *inode = file->f_mapping->host;
Fan Yongd1f52732012-03-18 22:44:40 -0400325 int dx_dir = is_dx_dir(inode);
Eric Sandeenec7268c2012-04-30 13:14:03 -0500326 loff_t htree_max = ext4_get_htree_eof(file);
Fan Yongd1f52732012-03-18 22:44:40 -0400327
Eric Sandeenec7268c2012-04-30 13:14:03 -0500328 if (likely(dx_dir))
Andrew Morton965c8e52012-12-17 15:59:39 -0800329 return generic_file_llseek_size(file, offset, whence,
Eric Sandeenec7268c2012-04-30 13:14:03 -0500330 htree_max, htree_max);
331 else
Andrew Morton965c8e52012-12-17 15:59:39 -0800332 return ext4_llseek(file, offset, whence);
Fan Yongd1f52732012-03-18 22:44:40 -0400333}
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700334
335/*
336 * This structure holds the nodes of the red-black tree used to store
337 * the directory entry in hash order.
338 */
339struct fname {
340 __u32 hash;
341 __u32 minor_hash;
342 struct rb_node rb_hash;
343 struct fname *next;
344 __u32 inode;
345 __u8 name_len;
346 __u8 file_type;
347 char name[0];
348};
349
350/*
351 * This functoin implements a non-recursive way of freeing all of the
352 * nodes in the red-black tree.
353 */
354static void free_rb_tree_fname(struct rb_root *root)
355{
Cody P Schaferd1866bd2014-01-23 15:56:10 -0800356 struct fname *fname, *next;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700357
Cody P Schaferd1866bd2014-01-23 15:56:10 -0800358 rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700359 while (fname) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400360 struct fname *old = fname;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700361 fname = fname->next;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400362 kfree(old);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700363 }
Cody P Schaferd1866bd2014-01-23 15:56:10 -0800364
365 *root = RB_ROOT;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700366}
367
368
Fan Yongd1f52732012-03-18 22:44:40 -0400369static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp,
370 loff_t pos)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700371{
372 struct dir_private_info *p;
373
Shen Feng69baee02008-07-11 19:27:31 -0400374 p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700375 if (!p)
376 return NULL;
Fan Yongd1f52732012-03-18 22:44:40 -0400377 p->curr_hash = pos2maj_hash(filp, pos);
378 p->curr_minor_hash = pos2min_hash(filp, pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700379 return p;
380}
381
Mingming Cao617ba132006-10-11 01:20:53 -0700382void ext4_htree_free_dir_info(struct dir_private_info *p)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700383{
384 free_rb_tree_fname(&p->root);
385 kfree(p);
386}
387
388/*
389 * Given a directory entry, enter it into the fname rb tree.
390 */
Mingming Cao617ba132006-10-11 01:20:53 -0700391int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700392 __u32 minor_hash,
Mingming Cao617ba132006-10-11 01:20:53 -0700393 struct ext4_dir_entry_2 *dirent)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700394{
395 struct rb_node **p, *parent = NULL;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400396 struct fname *fname, *new_fn;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700397 struct dir_private_info *info;
398 int len;
399
Joe Perchesa271fe82010-07-27 11:56:04 -0400400 info = dir_file->private_data;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700401 p = &info->root.rb_node;
402
403 /* Create and allocate the fname structure */
404 len = sizeof(struct fname) + dirent->name_len + 1;
405 new_fn = kzalloc(len, GFP_KERNEL);
406 if (!new_fn)
407 return -ENOMEM;
408 new_fn->hash = hash;
409 new_fn->minor_hash = minor_hash;
410 new_fn->inode = le32_to_cpu(dirent->inode);
411 new_fn->name_len = dirent->name_len;
412 new_fn->file_type = dirent->file_type;
413 memcpy(new_fn->name, dirent->name, dirent->name_len);
414 new_fn->name[dirent->name_len] = 0;
415
416 while (*p) {
417 parent = *p;
418 fname = rb_entry(parent, struct fname, rb_hash);
419
420 /*
421 * If the hash and minor hash match up, then we put
422 * them on a linked list. This rarely happens...
423 */
424 if ((new_fn->hash == fname->hash) &&
425 (new_fn->minor_hash == fname->minor_hash)) {
426 new_fn->next = fname->next;
427 fname->next = new_fn;
428 return 0;
429 }
430
431 if (new_fn->hash < fname->hash)
432 p = &(*p)->rb_left;
433 else if (new_fn->hash > fname->hash)
434 p = &(*p)->rb_right;
435 else if (new_fn->minor_hash < fname->minor_hash)
436 p = &(*p)->rb_left;
437 else /* if (new_fn->minor_hash > fname->minor_hash) */
438 p = &(*p)->rb_right;
439 }
440
441 rb_link_node(&new_fn->rb_hash, parent, p);
442 rb_insert_color(&new_fn->rb_hash, &info->root);
443 return 0;
444}
445
446
447
448/*
Mingming Cao617ba132006-10-11 01:20:53 -0700449 * This is a helper function for ext4_dx_readdir. It calls filldir
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700450 * for all entres on the fname linked list. (Normally there is only
451 * one entry on the linked list, unless there are 62 bit hash collisions.)
452 */
Al Viro725bebb2013-05-17 16:08:53 -0400453static int call_filldir(struct file *file, struct dir_context *ctx,
454 struct fname *fname)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700455{
Al Viro725bebb2013-05-17 16:08:53 -0400456 struct dir_private_info *info = file->private_data;
457 struct inode *inode = file_inode(file);
458 struct super_block *sb = inode->i_sb;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700459
460 if (!fname) {
Theodore Ts'o92b97812012-03-19 23:41:49 -0400461 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: "
462 "called with null fname?!?", __func__, __LINE__,
463 inode->i_ino, current->comm);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700464 return 0;
465 }
Al Viro725bebb2013-05-17 16:08:53 -0400466 ctx->pos = hash2pos(file, fname->hash, fname->minor_hash);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700467 while (fname) {
Al Viro725bebb2013-05-17 16:08:53 -0400468 if (!dir_emit(ctx, fname->name,
469 fname->name_len,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700470 fname->inode,
Al Viro725bebb2013-05-17 16:08:53 -0400471 get_dtype(sb, fname->file_type))) {
Theodore Ts'od0156412008-08-19 21:57:43 -0400472 info->extra_fname = fname;
Al Viro725bebb2013-05-17 16:08:53 -0400473 return 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700474 }
475 fname = fname->next;
476 }
477 return 0;
478}
479
Al Viro725bebb2013-05-17 16:08:53 -0400480static int ext4_dx_readdir(struct file *file, struct dir_context *ctx)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700481{
Al Viro725bebb2013-05-17 16:08:53 -0400482 struct dir_private_info *info = file->private_data;
483 struct inode *inode = file_inode(file);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700484 struct fname *fname;
485 int ret;
486
487 if (!info) {
Al Viro725bebb2013-05-17 16:08:53 -0400488 info = ext4_htree_create_dir_info(file, ctx->pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700489 if (!info)
490 return -ENOMEM;
Al Viro725bebb2013-05-17 16:08:53 -0400491 file->private_data = info;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700492 }
493
Al Viro725bebb2013-05-17 16:08:53 -0400494 if (ctx->pos == ext4_get_htree_eof(file))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700495 return 0; /* EOF */
496
497 /* Some one has messed with f_pos; reset the world */
Al Viro725bebb2013-05-17 16:08:53 -0400498 if (info->last_pos != ctx->pos) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700499 free_rb_tree_fname(&info->root);
500 info->curr_node = NULL;
501 info->extra_fname = NULL;
Al Viro725bebb2013-05-17 16:08:53 -0400502 info->curr_hash = pos2maj_hash(file, ctx->pos);
503 info->curr_minor_hash = pos2min_hash(file, ctx->pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700504 }
505
506 /*
507 * If there are any leftover names on the hash collision
508 * chain, return them first.
509 */
Theodore Ts'od0156412008-08-19 21:57:43 -0400510 if (info->extra_fname) {
Al Viro725bebb2013-05-17 16:08:53 -0400511 if (call_filldir(file, ctx, info->extra_fname))
Theodore Ts'od0156412008-08-19 21:57:43 -0400512 goto finished;
Theodore Ts'od0156412008-08-19 21:57:43 -0400513 info->extra_fname = NULL;
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400514 goto next_node;
Theodore Ts'od0156412008-08-19 21:57:43 -0400515 } else if (!info->curr_node)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700516 info->curr_node = rb_first(&info->root);
517
518 while (1) {
519 /*
520 * Fill the rbtree if we have no more entries,
521 * or the inode has changed since we last read in the
522 * cached entries.
523 */
524 if ((!info->curr_node) ||
Al Viro725bebb2013-05-17 16:08:53 -0400525 (file->f_version != inode->i_version)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700526 info->curr_node = NULL;
527 free_rb_tree_fname(&info->root);
Al Viro725bebb2013-05-17 16:08:53 -0400528 file->f_version = inode->i_version;
529 ret = ext4_htree_fill_tree(file, info->curr_hash,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700530 info->curr_minor_hash,
531 &info->next_hash);
532 if (ret < 0)
533 return ret;
534 if (ret == 0) {
Al Viro725bebb2013-05-17 16:08:53 -0400535 ctx->pos = ext4_get_htree_eof(file);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700536 break;
537 }
538 info->curr_node = rb_first(&info->root);
539 }
540
541 fname = rb_entry(info->curr_node, struct fname, rb_hash);
542 info->curr_hash = fname->hash;
543 info->curr_minor_hash = fname->minor_hash;
Al Viro725bebb2013-05-17 16:08:53 -0400544 if (call_filldir(file, ctx, fname))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700545 break;
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400546 next_node:
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700547 info->curr_node = rb_next(info->curr_node);
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400548 if (info->curr_node) {
549 fname = rb_entry(info->curr_node, struct fname,
550 rb_hash);
551 info->curr_hash = fname->hash;
552 info->curr_minor_hash = fname->minor_hash;
553 } else {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700554 if (info->next_hash == ~0) {
Al Viro725bebb2013-05-17 16:08:53 -0400555 ctx->pos = ext4_get_htree_eof(file);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700556 break;
557 }
558 info->curr_hash = info->next_hash;
559 info->curr_minor_hash = 0;
560 }
561 }
562finished:
Al Viro725bebb2013-05-17 16:08:53 -0400563 info->last_pos = ctx->pos;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700564 return 0;
565}
566
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400567static int ext4_release_dir(struct inode *inode, struct file *filp)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700568{
Andrew Morton63f57932006-10-11 01:21:24 -0700569 if (filp->private_data)
Mingming Cao617ba132006-10-11 01:20:53 -0700570 ext4_htree_free_dir_info(filp->private_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700571
572 return 0;
573}
Fan Yongd1f52732012-03-18 22:44:40 -0400574
575const struct file_operations ext4_dir_operations = {
576 .llseek = ext4_dir_llseek,
577 .read = generic_read_dir,
Al Viro725bebb2013-05-17 16:08:53 -0400578 .iterate = ext4_readdir,
Fan Yongd1f52732012-03-18 22:44:40 -0400579 .unlocked_ioctl = ext4_ioctl,
580#ifdef CONFIG_COMPAT
581 .compat_ioctl = ext4_compat_ioctl,
582#endif
583 .fsync = ext4_sync_file,
584 .release = ext4_release_dir,
585};