blob: 33f5e2a50cf883c43842e1c89a868fcf70c4c2a9 [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>
Dave Kleikampac27a0e2006-10-11 01:20:50 -070025#include <linux/buffer_head.h>
Dave Kleikampac27a0e2006-10-11 01:20:50 -070026#include <linux/slab.h>
Christoph Hellwig3dcf5452008-04-29 18:13:32 -040027#include "ext4.h"
Tao Ma65d165d2012-12-10 14:05:59 -050028#include "xattr.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070029
Al Viro725bebb2013-05-17 16:08:53 -040030static int ext4_dx_readdir(struct file *, struct dir_context *);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070031
Fan Yongd1f52732012-03-18 22:44:40 -040032/**
33 * Check if the given dir-inode refers to an htree-indexed directory
Anatol Pomozov70261f52013-08-28 14:40:12 -040034 * (or a directory which could potentially get converted to use htree
Fan Yongd1f52732012-03-18 22:44:40 -040035 * indexing).
36 *
37 * Return 1 if it is a dx dir, 0 if not
38 */
39static int is_dx_dir(struct inode *inode)
40{
41 struct super_block *sb = inode->i_sb;
42
Darrick J. Wonge2b911c2015-10-17 16:18:43 -040043 if (ext4_has_feature_dir_index(inode->i_sb) &&
Fan Yongd1f52732012-03-18 22:44:40 -040044 ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) ||
Tao Ma8af0f082013-04-19 17:53:09 -040045 ((inode->i_size >> sb->s_blocksize_bits) == 1) ||
46 ext4_has_inline_data(inode)))
Fan Yongd1f52732012-03-18 22:44:40 -040047 return 1;
48
49 return 0;
50}
51
Theodore Ts'ocad3f002010-12-19 22:07:02 -050052/*
53 * Return 0 if the directory entry is OK, and 1 if there is a problem
54 *
55 * Note: this is the opposite of what ext2 and ext3 historically returned...
Tao Ma65d165d2012-12-10 14:05:59 -050056 *
57 * bh passed here can be an inode block or a dir data block, depending
58 * on the inode inline data flag.
Theodore Ts'ocad3f002010-12-19 22:07:02 -050059 */
Theodore Ts'o60fd4da2010-07-27 11:54:40 -040060int __ext4_check_dir_entry(const char *function, unsigned int line,
Theodore Ts'of7c21172011-01-10 12:10:55 -050061 struct inode *dir, struct file *filp,
Theodore Ts'o60fd4da2010-07-27 11:54:40 -040062 struct ext4_dir_entry_2 *de,
Tao Ma226ba972012-12-10 14:05:58 -050063 struct buffer_head *bh, char *buf, int size,
Theodore Ts'o60fd4da2010-07-27 11:54:40 -040064 unsigned int offset)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070065{
Theodore Ts'oaf5bc922008-09-08 22:25:24 -040066 const char *error_msg = NULL;
Wei Yongjun3d0518f2009-02-14 23:01:36 -050067 const int rlen = ext4_rec_len_from_disk(de->rec_len,
68 dir->i_sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070069
Theodore Ts'ocad3f002010-12-19 22:07:02 -050070 if (unlikely(rlen < EXT4_DIR_REC_LEN(1)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070071 error_msg = "rec_len is smaller than minimal";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050072 else if (unlikely(rlen % 4 != 0))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070073 error_msg = "rec_len % 4 != 0";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050074 else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070075 error_msg = "rec_len is too small for name_len";
Tao Ma226ba972012-12-10 14:05:58 -050076 else if (unlikely(((char *) de - buf) + rlen > size))
77 error_msg = "directory entry across range";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050078 else if (unlikely(le32_to_cpu(de->inode) >
79 le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070080 error_msg = "inode out of bounds";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050081 else
82 return 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070083
Theodore Ts'of7c21172011-01-10 12:10:55 -050084 if (filp)
Dan Carpenter4fda4002012-02-20 17:53:05 -050085 ext4_error_file(filp, function, line, bh->b_blocknr,
Theodore Ts'of7c21172011-01-10 12:10:55 -050086 "bad entry in directory: %s - offset=%u(%u), "
87 "inode=%u, rec_len=%d, name_len=%d",
Tao Ma226ba972012-12-10 14:05:58 -050088 error_msg, (unsigned) (offset % size),
Theodore Ts'of7c21172011-01-10 12:10:55 -050089 offset, le32_to_cpu(de->inode),
90 rlen, de->name_len);
91 else
Dan Carpenter4fda4002012-02-20 17:53:05 -050092 ext4_error_inode(dir, function, line, bh->b_blocknr,
Theodore Ts'of7c21172011-01-10 12:10:55 -050093 "bad entry in directory: %s - offset=%u(%u), "
94 "inode=%u, rec_len=%d, name_len=%d",
Tao Ma226ba972012-12-10 14:05:58 -050095 error_msg, (unsigned) (offset % size),
Theodore Ts'of7c21172011-01-10 12:10:55 -050096 offset, le32_to_cpu(de->inode),
97 rlen, de->name_len);
98
Theodore Ts'ocad3f002010-12-19 22:07:02 -050099 return 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700100}
101
Al Viro725bebb2013-05-17 16:08:53 -0400102static int ext4_readdir(struct file *file, struct dir_context *ctx)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700103{
Theodore Ts'o498e5f22008-11-05 00:14:04 -0500104 unsigned int offset;
Giedrius Rekasiusaa13d5f2014-05-27 12:48:55 -0400105 int i;
Mingming Cao617ba132006-10-11 01:20:53 -0700106 struct ext4_dir_entry_2 *de;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700107 int err;
Al Viro725bebb2013-05-17 16:08:53 -0400108 struct inode *inode = file_inode(file);
Fan Yongd1f52732012-03-18 22:44:40 -0400109 struct super_block *sb = inode->i_sb;
Michael Halcrow44614712015-04-12 01:09:05 -0400110 struct buffer_head *bh = NULL;
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400111 int dir_has_error = 0;
Michael Halcrow44614712015-04-12 01:09:05 -0400112 struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700113
Theodore Ts'o28b4c262016-02-07 19:35:05 -0500114 if (ext4_encrypted_inode(inode)) {
115 err = ext4_get_encryption_info(inode);
116 if (err && err != -ENOKEY)
117 return err;
118 }
119
Fan Yongd1f52732012-03-18 22:44:40 -0400120 if (is_dx_dir(inode)) {
Al Viro725bebb2013-05-17 16:08:53 -0400121 err = ext4_dx_readdir(file, ctx);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700122 if (err != ERR_BAD_DX_DIR) {
Al Viro725bebb2013-05-17 16:08:53 -0400123 return err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700124 }
125 /*
126 * We don't set the inode dirty flag since it's not
127 * critical that it get flushed back to the disk.
128 */
Al Viro725bebb2013-05-17 16:08:53 -0400129 ext4_clear_inode_flag(file_inode(file),
Theodore Ts'o07a03822010-06-14 09:54:48 -0400130 EXT4_INODE_INDEX);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700131 }
Tao Ma8af0f082013-04-19 17:53:09 -0400132
133 if (ext4_has_inline_data(inode)) {
134 int has_inline_data = 1;
Michael Halcrow44614712015-04-12 01:09:05 -0400135 err = ext4_read_inline_dir(file, ctx,
Tao Ma8af0f082013-04-19 17:53:09 -0400136 &has_inline_data);
137 if (has_inline_data)
Michael Halcrow44614712015-04-12 01:09:05 -0400138 return err;
139 }
140
Theodore Ts'ob7236e22015-05-18 13:17:47 -0400141 if (ext4_encrypted_inode(inode)) {
142 err = ext4_fname_crypto_alloc_buffer(inode, EXT4_NAME_LEN,
Michael Halcrow44614712015-04-12 01:09:05 -0400143 &fname_crypto_str);
Theodore Ts'ob7236e22015-05-18 13:17:47 -0400144 if (err < 0)
Michael Halcrow44614712015-04-12 01:09:05 -0400145 return err;
Tao Ma8af0f082013-04-19 17:53:09 -0400146 }
147
Al Viro725bebb2013-05-17 16:08:53 -0400148 offset = ctx->pos & (sb->s_blocksize - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700149
Al Viro725bebb2013-05-17 16:08:53 -0400150 while (ctx->pos < inode->i_size) {
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400151 struct ext4_map_blocks map;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700152
Al Viro725bebb2013-05-17 16:08:53 -0400153 map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb);
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400154 map.m_len = 1;
155 err = ext4_map_blocks(NULL, inode, &map, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700156 if (err > 0) {
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400157 pgoff_t index = map.m_pblk >>
Fengguang Wudc7868f2007-07-19 01:48:04 -0700158 (PAGE_CACHE_SHIFT - inode->i_blkbits);
Al Viro725bebb2013-05-17 16:08:53 -0400159 if (!ra_has_index(&file->f_ra, index))
Rusty Russellcf914a72007-07-19 01:48:08 -0700160 page_cache_sync_readahead(
Fengguang Wudc7868f2007-07-19 01:48:04 -0700161 sb->s_bdev->bd_inode->i_mapping,
Al Viro725bebb2013-05-17 16:08:53 -0400162 &file->f_ra, file,
Rusty Russellcf914a72007-07-19 01:48:08 -0700163 index, 1);
Al Viro725bebb2013-05-17 16:08:53 -0400164 file->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
Theodore Ts'o1c215022014-08-29 20:52:15 -0400165 bh = ext4_bread(NULL, inode, map.m_lblk, 0);
Kirill Tkhaic906f382016-02-16 00:20:19 -0500166 if (IS_ERR(bh)) {
167 err = PTR_ERR(bh);
168 bh = NULL;
169 goto errout;
170 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700171 }
172
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700173 if (!bh) {
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400174 if (!dir_has_error) {
Al Viro725bebb2013-05-17 16:08:53 -0400175 EXT4_ERROR_FILE(file, 0,
Theodore Ts'of7c21172011-01-10 12:10:55 -0500176 "directory contains a "
177 "hole at offset %llu",
Al Viro725bebb2013-05-17 16:08:53 -0400178 (unsigned long long) ctx->pos);
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400179 dir_has_error = 1;
180 }
Eric Sandeene6c40212006-12-06 20:36:28 -0800181 /* corrupt size? Maybe no more blocks to read */
Al Viro725bebb2013-05-17 16:08:53 -0400182 if (ctx->pos > inode->i_blocks << 9)
Eric Sandeene6c40212006-12-06 20:36:28 -0800183 break;
Al Viro725bebb2013-05-17 16:08:53 -0400184 ctx->pos += sb->s_blocksize - offset;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700185 continue;
186 }
187
Darrick J. Wongb0336e82012-04-29 18:41:10 -0400188 /* Check the checksum */
189 if (!buffer_verified(bh) &&
190 !ext4_dirent_csum_verify(inode,
191 (struct ext4_dir_entry *)bh->b_data)) {
Al Viro725bebb2013-05-17 16:08:53 -0400192 EXT4_ERROR_FILE(file, 0, "directory fails checksum "
Darrick J. Wongb0336e82012-04-29 18:41:10 -0400193 "at offset %llu",
Al Viro725bebb2013-05-17 16:08:53 -0400194 (unsigned long long)ctx->pos);
195 ctx->pos += sb->s_blocksize - offset;
Guo Chaod5ac7772013-01-28 21:23:24 -0500196 brelse(bh);
Michael Halcrow44614712015-04-12 01:09:05 -0400197 bh = NULL;
Darrick J. Wongb0336e82012-04-29 18:41:10 -0400198 continue;
199 }
200 set_buffer_verified(bh);
201
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700202 /* If the dir block has changed since the last call to
203 * readdir(2), then we might be pointing to an invalid
204 * dirent right now. Scan from the start of the block
205 * to make sure. */
Al Viro725bebb2013-05-17 16:08:53 -0400206 if (file->f_version != inode->i_version) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700207 for (i = 0; i < sb->s_blocksize && i < offset; ) {
Mingming Cao617ba132006-10-11 01:20:53 -0700208 de = (struct ext4_dir_entry_2 *)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700209 (bh->b_data + i);
210 /* It's too expensive to do a full
211 * dirent test each time round this
212 * loop, but we do have to test at
213 * least that it is non-zero. A
214 * failure will be detected in the
215 * dirent test below. */
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500216 if (ext4_rec_len_from_disk(de->rec_len,
217 sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700218 break;
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500219 i += ext4_rec_len_from_disk(de->rec_len,
220 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700221 }
222 offset = i;
Al Viro725bebb2013-05-17 16:08:53 -0400223 ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700224 | offset;
Al Viro725bebb2013-05-17 16:08:53 -0400225 file->f_version = inode->i_version;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700226 }
227
Al Viro725bebb2013-05-17 16:08:53 -0400228 while (ctx->pos < inode->i_size
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700229 && offset < sb->s_blocksize) {
Mingming Cao617ba132006-10-11 01:20:53 -0700230 de = (struct ext4_dir_entry_2 *) (bh->b_data + offset);
Al Viro725bebb2013-05-17 16:08:53 -0400231 if (ext4_check_dir_entry(inode, file, de, bh,
Tao Ma226ba972012-12-10 14:05:58 -0500232 bh->b_data, bh->b_size,
233 offset)) {
Andrew Morton63f57932006-10-11 01:21:24 -0700234 /*
Al Viro725bebb2013-05-17 16:08:53 -0400235 * On error, skip to the next block
Andrew Morton63f57932006-10-11 01:21:24 -0700236 */
Al Viro725bebb2013-05-17 16:08:53 -0400237 ctx->pos = (ctx->pos |
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700238 (sb->s_blocksize - 1)) + 1;
Al Viro725bebb2013-05-17 16:08:53 -0400239 break;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700240 }
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500241 offset += ext4_rec_len_from_disk(de->rec_len,
242 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700243 if (le32_to_cpu(de->inode)) {
Theodore Ts'ob7236e22015-05-18 13:17:47 -0400244 if (!ext4_encrypted_inode(inode)) {
Michael Halcrow44614712015-04-12 01:09:05 -0400245 if (!dir_emit(ctx, de->name,
246 de->name_len,
247 le32_to_cpu(de->inode),
248 get_dtype(sb, de->file_type)))
249 goto done;
250 } else {
Theodore Ts'od2299592015-05-18 13:15:47 -0400251 int save_len = fname_crypto_str.len;
252
Michael Halcrow44614712015-04-12 01:09:05 -0400253 /* Directory is encrypted */
Theodore Ts'ob7236e22015-05-18 13:17:47 -0400254 err = ext4_fname_disk_to_usr(inode,
Theodore Ts'o5de0b4d2015-05-01 16:56:45 -0400255 NULL, de, &fname_crypto_str);
Theodore Ts'od2299592015-05-18 13:15:47 -0400256 fname_crypto_str.len = save_len;
Michael Halcrow44614712015-04-12 01:09:05 -0400257 if (err < 0)
258 goto errout;
259 if (!dir_emit(ctx,
260 fname_crypto_str.name, err,
261 le32_to_cpu(de->inode),
262 get_dtype(sb, de->file_type)))
263 goto done;
Al Viro725bebb2013-05-17 16:08:53 -0400264 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700265 }
Al Viro725bebb2013-05-17 16:08:53 -0400266 ctx->pos += ext4_rec_len_from_disk(de->rec_len,
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500267 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700268 }
Michael Halcrow44614712015-04-12 01:09:05 -0400269 if ((ctx->pos < inode->i_size) && !dir_relax(inode))
270 goto done;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400271 brelse(bh);
Michael Halcrow44614712015-04-12 01:09:05 -0400272 bh = NULL;
273 offset = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700274 }
Michael Halcrow44614712015-04-12 01:09:05 -0400275done:
276 err = 0;
277errout:
278#ifdef CONFIG_EXT4_FS_ENCRYPTION
Michael Halcrow44614712015-04-12 01:09:05 -0400279 ext4_fname_crypto_free_buffer(&fname_crypto_str);
280#endif
281 brelse(bh);
282 return err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700283}
284
Fan Yongd1f52732012-03-18 22:44:40 -0400285static inline int is_32bit_api(void)
286{
287#ifdef CONFIG_COMPAT
288 return is_compat_task();
289#else
290 return (BITS_PER_LONG == 32);
291#endif
292}
293
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700294/*
295 * These functions convert from the major/minor hash to an f_pos
Fan Yongd1f52732012-03-18 22:44:40 -0400296 * value for dx directories
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700297 *
Fan Yongd1f52732012-03-18 22:44:40 -0400298 * Upper layer (for example NFS) should specify FMODE_32BITHASH or
299 * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted
300 * directly on both 32-bit and 64-bit nodes, under such case, neither
301 * FMODE_32BITHASH nor FMODE_64BITHASH is specified.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700302 */
Fan Yongd1f52732012-03-18 22:44:40 -0400303static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor)
304{
305 if ((filp->f_mode & FMODE_32BITHASH) ||
306 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
307 return major >> 1;
308 else
309 return ((__u64)(major >> 1) << 32) | (__u64)minor;
310}
311
312static inline __u32 pos2maj_hash(struct file *filp, loff_t pos)
313{
314 if ((filp->f_mode & FMODE_32BITHASH) ||
315 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
316 return (pos << 1) & 0xffffffff;
317 else
318 return ((pos >> 32) << 1) & 0xffffffff;
319}
320
321static inline __u32 pos2min_hash(struct file *filp, loff_t pos)
322{
323 if ((filp->f_mode & FMODE_32BITHASH) ||
324 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
325 return 0;
326 else
327 return pos & 0xffffffff;
328}
329
330/*
331 * Return 32- or 64-bit end-of-file for dx directories
332 */
333static inline loff_t ext4_get_htree_eof(struct file *filp)
334{
335 if ((filp->f_mode & FMODE_32BITHASH) ||
336 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
337 return EXT4_HTREE_EOF_32BIT;
338 else
339 return EXT4_HTREE_EOF_64BIT;
340}
341
342
343/*
Eric Sandeenec7268c2012-04-30 13:14:03 -0500344 * ext4_dir_llseek() calls generic_file_llseek_size to handle htree
345 * directories, where the "offset" is in terms of the filename hash
346 * value instead of the byte offset.
Fan Yongd1f52732012-03-18 22:44:40 -0400347 *
Eric Sandeenec7268c2012-04-30 13:14:03 -0500348 * Because we may return a 64-bit hash that is well beyond offset limits,
349 * we need to pass the max hash as the maximum allowable offset in
350 * the htree directory case.
351 *
352 * For non-htree, ext4_llseek already chooses the proper max offset.
Fan Yongd1f52732012-03-18 22:44:40 -0400353 */
Zheng Liud4e43952013-03-02 17:24:05 -0500354static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence)
Fan Yongd1f52732012-03-18 22:44:40 -0400355{
356 struct inode *inode = file->f_mapping->host;
Fan Yongd1f52732012-03-18 22:44:40 -0400357 int dx_dir = is_dx_dir(inode);
Eric Sandeenec7268c2012-04-30 13:14:03 -0500358 loff_t htree_max = ext4_get_htree_eof(file);
Fan Yongd1f52732012-03-18 22:44:40 -0400359
Eric Sandeenec7268c2012-04-30 13:14:03 -0500360 if (likely(dx_dir))
Andrew Morton965c8e52012-12-17 15:59:39 -0800361 return generic_file_llseek_size(file, offset, whence,
Eric Sandeenec7268c2012-04-30 13:14:03 -0500362 htree_max, htree_max);
363 else
Andrew Morton965c8e52012-12-17 15:59:39 -0800364 return ext4_llseek(file, offset, whence);
Fan Yongd1f52732012-03-18 22:44:40 -0400365}
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700366
367/*
368 * This structure holds the nodes of the red-black tree used to store
369 * the directory entry in hash order.
370 */
371struct fname {
372 __u32 hash;
373 __u32 minor_hash;
374 struct rb_node rb_hash;
375 struct fname *next;
376 __u32 inode;
377 __u8 name_len;
378 __u8 file_type;
379 char name[0];
380};
381
382/*
383 * This functoin implements a non-recursive way of freeing all of the
384 * nodes in the red-black tree.
385 */
386static void free_rb_tree_fname(struct rb_root *root)
387{
Cody P Schaferd1866bd2014-01-23 15:56:10 -0800388 struct fname *fname, *next;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700389
Cody P Schaferd1866bd2014-01-23 15:56:10 -0800390 rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700391 while (fname) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400392 struct fname *old = fname;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700393 fname = fname->next;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400394 kfree(old);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700395 }
Cody P Schaferd1866bd2014-01-23 15:56:10 -0800396
397 *root = RB_ROOT;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700398}
399
400
Fan Yongd1f52732012-03-18 22:44:40 -0400401static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp,
402 loff_t pos)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700403{
404 struct dir_private_info *p;
405
Shen Feng69baee02008-07-11 19:27:31 -0400406 p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700407 if (!p)
408 return NULL;
Fan Yongd1f52732012-03-18 22:44:40 -0400409 p->curr_hash = pos2maj_hash(filp, pos);
410 p->curr_minor_hash = pos2min_hash(filp, pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700411 return p;
412}
413
Mingming Cao617ba132006-10-11 01:20:53 -0700414void ext4_htree_free_dir_info(struct dir_private_info *p)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700415{
416 free_rb_tree_fname(&p->root);
417 kfree(p);
418}
419
420/*
421 * Given a directory entry, enter it into the fname rb tree.
Theodore Ts'o2f618302015-04-12 00:56:26 -0400422 *
423 * When filename encryption is enabled, the dirent will hold the
424 * encrypted filename, while the htree will hold decrypted filename.
425 * The decrypted filename is passed in via ent_name. parameter.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700426 */
Mingming Cao617ba132006-10-11 01:20:53 -0700427int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700428 __u32 minor_hash,
Theodore Ts'o2f618302015-04-12 00:56:26 -0400429 struct ext4_dir_entry_2 *dirent,
430 struct ext4_str *ent_name)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700431{
432 struct rb_node **p, *parent = NULL;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400433 struct fname *fname, *new_fn;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700434 struct dir_private_info *info;
435 int len;
436
Joe Perchesa271fe82010-07-27 11:56:04 -0400437 info = dir_file->private_data;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700438 p = &info->root.rb_node;
439
440 /* Create and allocate the fname structure */
Theodore Ts'o2f618302015-04-12 00:56:26 -0400441 len = sizeof(struct fname) + ent_name->len + 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700442 new_fn = kzalloc(len, GFP_KERNEL);
443 if (!new_fn)
444 return -ENOMEM;
445 new_fn->hash = hash;
446 new_fn->minor_hash = minor_hash;
447 new_fn->inode = le32_to_cpu(dirent->inode);
Theodore Ts'o2f618302015-04-12 00:56:26 -0400448 new_fn->name_len = ent_name->len;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700449 new_fn->file_type = dirent->file_type;
Theodore Ts'o2f618302015-04-12 00:56:26 -0400450 memcpy(new_fn->name, ent_name->name, ent_name->len);
451 new_fn->name[ent_name->len] = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700452
453 while (*p) {
454 parent = *p;
455 fname = rb_entry(parent, struct fname, rb_hash);
456
457 /*
458 * If the hash and minor hash match up, then we put
459 * them on a linked list. This rarely happens...
460 */
461 if ((new_fn->hash == fname->hash) &&
462 (new_fn->minor_hash == fname->minor_hash)) {
463 new_fn->next = fname->next;
464 fname->next = new_fn;
465 return 0;
466 }
467
468 if (new_fn->hash < fname->hash)
469 p = &(*p)->rb_left;
470 else if (new_fn->hash > fname->hash)
471 p = &(*p)->rb_right;
472 else if (new_fn->minor_hash < fname->minor_hash)
473 p = &(*p)->rb_left;
474 else /* if (new_fn->minor_hash > fname->minor_hash) */
475 p = &(*p)->rb_right;
476 }
477
478 rb_link_node(&new_fn->rb_hash, parent, p);
479 rb_insert_color(&new_fn->rb_hash, &info->root);
480 return 0;
481}
482
483
484
485/*
Mingming Cao617ba132006-10-11 01:20:53 -0700486 * This is a helper function for ext4_dx_readdir. It calls filldir
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700487 * for all entres on the fname linked list. (Normally there is only
488 * one entry on the linked list, unless there are 62 bit hash collisions.)
489 */
Al Viro725bebb2013-05-17 16:08:53 -0400490static int call_filldir(struct file *file, struct dir_context *ctx,
491 struct fname *fname)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700492{
Al Viro725bebb2013-05-17 16:08:53 -0400493 struct dir_private_info *info = file->private_data;
494 struct inode *inode = file_inode(file);
495 struct super_block *sb = inode->i_sb;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700496
497 if (!fname) {
Theodore Ts'o92b97812012-03-19 23:41:49 -0400498 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: "
499 "called with null fname?!?", __func__, __LINE__,
500 inode->i_ino, current->comm);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700501 return 0;
502 }
Al Viro725bebb2013-05-17 16:08:53 -0400503 ctx->pos = hash2pos(file, fname->hash, fname->minor_hash);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700504 while (fname) {
Al Viro725bebb2013-05-17 16:08:53 -0400505 if (!dir_emit(ctx, fname->name,
506 fname->name_len,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700507 fname->inode,
Al Viro725bebb2013-05-17 16:08:53 -0400508 get_dtype(sb, fname->file_type))) {
Theodore Ts'od0156412008-08-19 21:57:43 -0400509 info->extra_fname = fname;
Al Viro725bebb2013-05-17 16:08:53 -0400510 return 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700511 }
512 fname = fname->next;
513 }
514 return 0;
515}
516
Al Viro725bebb2013-05-17 16:08:53 -0400517static int ext4_dx_readdir(struct file *file, struct dir_context *ctx)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700518{
Al Viro725bebb2013-05-17 16:08:53 -0400519 struct dir_private_info *info = file->private_data;
520 struct inode *inode = file_inode(file);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700521 struct fname *fname;
522 int ret;
523
524 if (!info) {
Al Viro725bebb2013-05-17 16:08:53 -0400525 info = ext4_htree_create_dir_info(file, ctx->pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700526 if (!info)
527 return -ENOMEM;
Al Viro725bebb2013-05-17 16:08:53 -0400528 file->private_data = info;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700529 }
530
Al Viro725bebb2013-05-17 16:08:53 -0400531 if (ctx->pos == ext4_get_htree_eof(file))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700532 return 0; /* EOF */
533
534 /* Some one has messed with f_pos; reset the world */
Al Viro725bebb2013-05-17 16:08:53 -0400535 if (info->last_pos != ctx->pos) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700536 free_rb_tree_fname(&info->root);
537 info->curr_node = NULL;
538 info->extra_fname = NULL;
Al Viro725bebb2013-05-17 16:08:53 -0400539 info->curr_hash = pos2maj_hash(file, ctx->pos);
540 info->curr_minor_hash = pos2min_hash(file, ctx->pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700541 }
542
543 /*
544 * If there are any leftover names on the hash collision
545 * chain, return them first.
546 */
Theodore Ts'od0156412008-08-19 21:57:43 -0400547 if (info->extra_fname) {
Al Viro725bebb2013-05-17 16:08:53 -0400548 if (call_filldir(file, ctx, info->extra_fname))
Theodore Ts'od0156412008-08-19 21:57:43 -0400549 goto finished;
Theodore Ts'od0156412008-08-19 21:57:43 -0400550 info->extra_fname = NULL;
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400551 goto next_node;
Theodore Ts'od0156412008-08-19 21:57:43 -0400552 } else if (!info->curr_node)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700553 info->curr_node = rb_first(&info->root);
554
555 while (1) {
556 /*
557 * Fill the rbtree if we have no more entries,
558 * or the inode has changed since we last read in the
559 * cached entries.
560 */
561 if ((!info->curr_node) ||
Al Viro725bebb2013-05-17 16:08:53 -0400562 (file->f_version != inode->i_version)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700563 info->curr_node = NULL;
564 free_rb_tree_fname(&info->root);
Al Viro725bebb2013-05-17 16:08:53 -0400565 file->f_version = inode->i_version;
566 ret = ext4_htree_fill_tree(file, info->curr_hash,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700567 info->curr_minor_hash,
568 &info->next_hash);
569 if (ret < 0)
570 return ret;
571 if (ret == 0) {
Al Viro725bebb2013-05-17 16:08:53 -0400572 ctx->pos = ext4_get_htree_eof(file);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700573 break;
574 }
575 info->curr_node = rb_first(&info->root);
576 }
577
578 fname = rb_entry(info->curr_node, struct fname, rb_hash);
579 info->curr_hash = fname->hash;
580 info->curr_minor_hash = fname->minor_hash;
Al Viro725bebb2013-05-17 16:08:53 -0400581 if (call_filldir(file, ctx, fname))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700582 break;
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400583 next_node:
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700584 info->curr_node = rb_next(info->curr_node);
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400585 if (info->curr_node) {
586 fname = rb_entry(info->curr_node, struct fname,
587 rb_hash);
588 info->curr_hash = fname->hash;
589 info->curr_minor_hash = fname->minor_hash;
590 } else {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700591 if (info->next_hash == ~0) {
Al Viro725bebb2013-05-17 16:08:53 -0400592 ctx->pos = ext4_get_htree_eof(file);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700593 break;
594 }
595 info->curr_hash = info->next_hash;
596 info->curr_minor_hash = 0;
597 }
598 }
599finished:
Al Viro725bebb2013-05-17 16:08:53 -0400600 info->last_pos = ctx->pos;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700601 return 0;
602}
603
Theodore Ts'o6bc445e2015-05-31 13:34:57 -0400604static int ext4_dir_open(struct inode * inode, struct file * filp)
605{
606 if (ext4_encrypted_inode(inode))
607 return ext4_get_encryption_info(inode) ? -EACCES : 0;
608 return 0;
609}
610
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400611static int ext4_release_dir(struct inode *inode, struct file *filp)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700612{
Andrew Morton63f57932006-10-11 01:21:24 -0700613 if (filp->private_data)
Mingming Cao617ba132006-10-11 01:20:53 -0700614 ext4_htree_free_dir_info(filp->private_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700615
616 return 0;
617}
Fan Yongd1f52732012-03-18 22:44:40 -0400618
Darrick J. Wong40b163f2014-07-28 13:06:26 -0400619int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf,
620 int buf_size)
621{
622 struct ext4_dir_entry_2 *de;
623 int nlen, rlen;
624 unsigned int offset = 0;
625 char *top;
626
627 de = (struct ext4_dir_entry_2 *)buf;
628 top = buf + buf_size;
629 while ((char *) de < top) {
630 if (ext4_check_dir_entry(dir, NULL, de, bh,
631 buf, buf_size, offset))
Darrick J. Wong6a797d22015-10-17 16:16:04 -0400632 return -EFSCORRUPTED;
Darrick J. Wong40b163f2014-07-28 13:06:26 -0400633 nlen = EXT4_DIR_REC_LEN(de->name_len);
634 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
635 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
636 offset += rlen;
637 }
638 if ((char *) de > top)
Darrick J. Wong6a797d22015-10-17 16:16:04 -0400639 return -EFSCORRUPTED;
Darrick J. Wong40b163f2014-07-28 13:06:26 -0400640
641 return 0;
642}
643
Fan Yongd1f52732012-03-18 22:44:40 -0400644const struct file_operations ext4_dir_operations = {
645 .llseek = ext4_dir_llseek,
646 .read = generic_read_dir,
Al Viro725bebb2013-05-17 16:08:53 -0400647 .iterate = ext4_readdir,
Fan Yongd1f52732012-03-18 22:44:40 -0400648 .unlocked_ioctl = ext4_ioctl,
649#ifdef CONFIG_COMPAT
650 .compat_ioctl = ext4_compat_ioctl,
651#endif
652 .fsync = ext4_sync_file,
Theodore Ts'o6bc445e2015-05-31 13:34:57 -0400653 .open = ext4_dir_open,
Fan Yongd1f52732012-03-18 22:44:40 -0400654 .release = ext4_release_dir,
655};