Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 1 | /* |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 2 | * linux/fs/ext4/dir.c |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 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 | * |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 15 | * ext4 directory handling functions |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 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 | |
| 24 | #include <linux/fs.h> |
Mingming Cao | dab291a | 2006-10-11 01:21:01 -0700 | [diff] [blame] | 25 | #include <linux/jbd2.h> |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 26 | #include <linux/ext4_fs.h> |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 27 | #include <linux/buffer_head.h> |
| 28 | #include <linux/smp_lock.h> |
| 29 | #include <linux/slab.h> |
| 30 | #include <linux/rbtree.h> |
| 31 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 32 | static unsigned char ext4_filetype_table[] = { |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 33 | DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK |
| 34 | }; |
| 35 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 36 | static int ext4_readdir(struct file *, void *, filldir_t); |
| 37 | static int ext4_dx_readdir(struct file * filp, |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 38 | void * dirent, filldir_t filldir); |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 39 | static int ext4_release_dir (struct inode * inode, |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 40 | struct file * filp); |
| 41 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 42 | const struct file_operations ext4_dir_operations = { |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 43 | .llseek = generic_file_llseek, |
| 44 | .read = generic_read_dir, |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 45 | .readdir = ext4_readdir, /* we take BKL. needed?*/ |
| 46 | .ioctl = ext4_ioctl, /* BKL held */ |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 47 | #ifdef CONFIG_COMPAT |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 48 | .compat_ioctl = ext4_compat_ioctl, |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 49 | #endif |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 50 | .fsync = ext4_sync_file, /* BKL held */ |
| 51 | #ifdef CONFIG_EXT4_INDEX |
| 52 | .release = ext4_release_dir, |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 53 | #endif |
| 54 | }; |
| 55 | |
| 56 | |
| 57 | static unsigned char get_dtype(struct super_block *sb, int filetype) |
| 58 | { |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 59 | if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) || |
| 60 | (filetype >= EXT4_FT_MAX)) |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 61 | return DT_UNKNOWN; |
| 62 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 63 | return (ext4_filetype_table[filetype]); |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 64 | } |
| 65 | |
| 66 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 67 | int ext4_check_dir_entry (const char * function, struct inode * dir, |
| 68 | struct ext4_dir_entry_2 * de, |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 69 | struct buffer_head * bh, |
| 70 | unsigned long offset) |
| 71 | { |
| 72 | const char * error_msg = NULL; |
| 73 | const int rlen = le16_to_cpu(de->rec_len); |
| 74 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 75 | if (rlen < EXT4_DIR_REC_LEN(1)) |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 76 | error_msg = "rec_len is smaller than minimal"; |
| 77 | else if (rlen % 4 != 0) |
| 78 | error_msg = "rec_len % 4 != 0"; |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 79 | else if (rlen < EXT4_DIR_REC_LEN(de->name_len)) |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 80 | error_msg = "rec_len is too small for name_len"; |
| 81 | else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize) |
| 82 | error_msg = "directory entry across blocks"; |
| 83 | else if (le32_to_cpu(de->inode) > |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 84 | le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count)) |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 85 | error_msg = "inode out of bounds"; |
| 86 | |
| 87 | if (error_msg != NULL) |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 88 | ext4_error (dir->i_sb, function, |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 89 | "bad entry in directory #%lu: %s - " |
| 90 | "offset=%lu, inode=%lu, rec_len=%d, name_len=%d", |
| 91 | dir->i_ino, error_msg, offset, |
| 92 | (unsigned long) le32_to_cpu(de->inode), |
| 93 | rlen, de->name_len); |
| 94 | return error_msg == NULL ? 1 : 0; |
| 95 | } |
| 96 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 97 | static int ext4_readdir(struct file * filp, |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 98 | void * dirent, filldir_t filldir) |
| 99 | { |
| 100 | int error = 0; |
| 101 | unsigned long offset; |
| 102 | int i, stored; |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 103 | struct ext4_dir_entry_2 *de; |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 104 | struct super_block *sb; |
| 105 | int err; |
Josef "Jeff" Sipek | 9d54989 | 2006-12-08 02:36:38 -0800 | [diff] [blame^] | 106 | struct inode *inode = filp->f_path.dentry->d_inode; |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 107 | int ret = 0; |
| 108 | |
| 109 | sb = inode->i_sb; |
| 110 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 111 | #ifdef CONFIG_EXT4_INDEX |
| 112 | if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb, |
| 113 | EXT4_FEATURE_COMPAT_DIR_INDEX) && |
| 114 | ((EXT4_I(inode)->i_flags & EXT4_INDEX_FL) || |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 115 | ((inode->i_size >> sb->s_blocksize_bits) == 1))) { |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 116 | err = ext4_dx_readdir(filp, dirent, filldir); |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 117 | if (err != ERR_BAD_DX_DIR) { |
| 118 | ret = err; |
| 119 | goto out; |
| 120 | } |
| 121 | /* |
| 122 | * We don't set the inode dirty flag since it's not |
| 123 | * critical that it get flushed back to the disk. |
| 124 | */ |
Josef "Jeff" Sipek | 9d54989 | 2006-12-08 02:36:38 -0800 | [diff] [blame^] | 125 | EXT4_I(filp->f_path.dentry->d_inode)->i_flags &= ~EXT4_INDEX_FL; |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 126 | } |
| 127 | #endif |
| 128 | stored = 0; |
| 129 | offset = filp->f_pos & (sb->s_blocksize - 1); |
| 130 | |
| 131 | while (!error && !stored && filp->f_pos < inode->i_size) { |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 132 | unsigned long blk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb); |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 133 | struct buffer_head map_bh; |
| 134 | struct buffer_head *bh = NULL; |
| 135 | |
| 136 | map_bh.b_state = 0; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 137 | err = ext4_get_blocks_wrap(NULL, inode, blk, 1, &map_bh, 0, 0); |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 138 | if (err > 0) { |
| 139 | page_cache_readahead(sb->s_bdev->bd_inode->i_mapping, |
| 140 | &filp->f_ra, |
| 141 | filp, |
| 142 | map_bh.b_blocknr >> |
| 143 | (PAGE_CACHE_SHIFT - inode->i_blkbits), |
| 144 | 1); |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 145 | bh = ext4_bread(NULL, inode, blk, 0, &err); |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 146 | } |
| 147 | |
| 148 | /* |
| 149 | * We ignore I/O errors on directories so users have a chance |
| 150 | * of recovering data when there's a bad sector |
| 151 | */ |
| 152 | if (!bh) { |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 153 | ext4_error (sb, "ext4_readdir", |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 154 | "directory #%lu contains a hole at offset %lu", |
| 155 | inode->i_ino, (unsigned long)filp->f_pos); |
Eric Sandeen | e6c4021 | 2006-12-06 20:36:28 -0800 | [diff] [blame] | 156 | /* corrupt size? Maybe no more blocks to read */ |
| 157 | if (filp->f_pos > inode->i_blocks << 9) |
| 158 | break; |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 159 | filp->f_pos += sb->s_blocksize - offset; |
| 160 | continue; |
| 161 | } |
| 162 | |
| 163 | revalidate: |
| 164 | /* If the dir block has changed since the last call to |
| 165 | * readdir(2), then we might be pointing to an invalid |
| 166 | * dirent right now. Scan from the start of the block |
| 167 | * to make sure. */ |
| 168 | if (filp->f_version != inode->i_version) { |
| 169 | for (i = 0; i < sb->s_blocksize && i < offset; ) { |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 170 | de = (struct ext4_dir_entry_2 *) |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 171 | (bh->b_data + i); |
| 172 | /* It's too expensive to do a full |
| 173 | * dirent test each time round this |
| 174 | * loop, but we do have to test at |
| 175 | * least that it is non-zero. A |
| 176 | * failure will be detected in the |
| 177 | * dirent test below. */ |
| 178 | if (le16_to_cpu(de->rec_len) < |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 179 | EXT4_DIR_REC_LEN(1)) |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 180 | break; |
| 181 | i += le16_to_cpu(de->rec_len); |
| 182 | } |
| 183 | offset = i; |
| 184 | filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1)) |
| 185 | | offset; |
| 186 | filp->f_version = inode->i_version; |
| 187 | } |
| 188 | |
| 189 | while (!error && filp->f_pos < inode->i_size |
| 190 | && offset < sb->s_blocksize) { |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 191 | de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); |
| 192 | if (!ext4_check_dir_entry ("ext4_readdir", inode, de, |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 193 | bh, offset)) { |
Andrew Morton | 63f5793 | 2006-10-11 01:21:24 -0700 | [diff] [blame] | 194 | /* |
| 195 | * On error, skip the f_pos to the next block |
| 196 | */ |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 197 | filp->f_pos = (filp->f_pos | |
| 198 | (sb->s_blocksize - 1)) + 1; |
| 199 | brelse (bh); |
| 200 | ret = stored; |
| 201 | goto out; |
| 202 | } |
| 203 | offset += le16_to_cpu(de->rec_len); |
| 204 | if (le32_to_cpu(de->inode)) { |
| 205 | /* We might block in the next section |
| 206 | * if the data destination is |
| 207 | * currently swapped out. So, use a |
| 208 | * version stamp to detect whether or |
| 209 | * not the directory has been modified |
| 210 | * during the copy operation. |
| 211 | */ |
| 212 | unsigned long version = filp->f_version; |
| 213 | |
| 214 | error = filldir(dirent, de->name, |
| 215 | de->name_len, |
| 216 | filp->f_pos, |
| 217 | le32_to_cpu(de->inode), |
| 218 | get_dtype(sb, de->file_type)); |
| 219 | if (error) |
| 220 | break; |
| 221 | if (version != filp->f_version) |
| 222 | goto revalidate; |
| 223 | stored ++; |
| 224 | } |
| 225 | filp->f_pos += le16_to_cpu(de->rec_len); |
| 226 | } |
| 227 | offset = 0; |
| 228 | brelse (bh); |
| 229 | } |
| 230 | out: |
| 231 | return ret; |
| 232 | } |
| 233 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 234 | #ifdef CONFIG_EXT4_INDEX |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 235 | /* |
| 236 | * These functions convert from the major/minor hash to an f_pos |
| 237 | * value. |
| 238 | * |
| 239 | * Currently we only use major hash numer. This is unfortunate, but |
| 240 | * on 32-bit machines, the same VFS interface is used for lseek and |
| 241 | * llseek, so if we use the 64 bit offset, then the 32-bit versions of |
| 242 | * lseek/telldir/seekdir will blow out spectacularly, and from within |
| 243 | * the ext2 low-level routine, we don't know if we're being called by |
| 244 | * a 64-bit version of the system call or the 32-bit version of the |
| 245 | * system call. Worse yet, NFSv2 only allows for a 32-bit readdir |
| 246 | * cookie. Sigh. |
| 247 | */ |
| 248 | #define hash2pos(major, minor) (major >> 1) |
| 249 | #define pos2maj_hash(pos) ((pos << 1) & 0xffffffff) |
| 250 | #define pos2min_hash(pos) (0) |
| 251 | |
| 252 | /* |
| 253 | * This structure holds the nodes of the red-black tree used to store |
| 254 | * the directory entry in hash order. |
| 255 | */ |
| 256 | struct fname { |
| 257 | __u32 hash; |
| 258 | __u32 minor_hash; |
| 259 | struct rb_node rb_hash; |
| 260 | struct fname *next; |
| 261 | __u32 inode; |
| 262 | __u8 name_len; |
| 263 | __u8 file_type; |
| 264 | char name[0]; |
| 265 | }; |
| 266 | |
| 267 | /* |
| 268 | * This functoin implements a non-recursive way of freeing all of the |
| 269 | * nodes in the red-black tree. |
| 270 | */ |
| 271 | static void free_rb_tree_fname(struct rb_root *root) |
| 272 | { |
| 273 | struct rb_node *n = root->rb_node; |
| 274 | struct rb_node *parent; |
| 275 | struct fname *fname; |
| 276 | |
| 277 | while (n) { |
| 278 | /* Do the node's children first */ |
| 279 | if ((n)->rb_left) { |
| 280 | n = n->rb_left; |
| 281 | continue; |
| 282 | } |
| 283 | if (n->rb_right) { |
| 284 | n = n->rb_right; |
| 285 | continue; |
| 286 | } |
| 287 | /* |
| 288 | * The node has no children; free it, and then zero |
| 289 | * out parent's link to it. Finally go to the |
| 290 | * beginning of the loop and try to free the parent |
| 291 | * node. |
| 292 | */ |
| 293 | parent = rb_parent(n); |
| 294 | fname = rb_entry(n, struct fname, rb_hash); |
| 295 | while (fname) { |
| 296 | struct fname * old = fname; |
| 297 | fname = fname->next; |
| 298 | kfree (old); |
| 299 | } |
| 300 | if (!parent) |
| 301 | root->rb_node = NULL; |
| 302 | else if (parent->rb_left == n) |
| 303 | parent->rb_left = NULL; |
| 304 | else if (parent->rb_right == n) |
| 305 | parent->rb_right = NULL; |
| 306 | n = parent; |
| 307 | } |
| 308 | root->rb_node = NULL; |
| 309 | } |
| 310 | |
| 311 | |
| 312 | static struct dir_private_info *create_dir_info(loff_t pos) |
| 313 | { |
| 314 | struct dir_private_info *p; |
| 315 | |
| 316 | p = kmalloc(sizeof(struct dir_private_info), GFP_KERNEL); |
| 317 | if (!p) |
| 318 | return NULL; |
| 319 | p->root.rb_node = NULL; |
| 320 | p->curr_node = NULL; |
| 321 | p->extra_fname = NULL; |
| 322 | p->last_pos = 0; |
| 323 | p->curr_hash = pos2maj_hash(pos); |
| 324 | p->curr_minor_hash = pos2min_hash(pos); |
| 325 | p->next_hash = 0; |
| 326 | return p; |
| 327 | } |
| 328 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 329 | void ext4_htree_free_dir_info(struct dir_private_info *p) |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 330 | { |
| 331 | free_rb_tree_fname(&p->root); |
| 332 | kfree(p); |
| 333 | } |
| 334 | |
| 335 | /* |
| 336 | * Given a directory entry, enter it into the fname rb tree. |
| 337 | */ |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 338 | int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 339 | __u32 minor_hash, |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 340 | struct ext4_dir_entry_2 *dirent) |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 341 | { |
| 342 | struct rb_node **p, *parent = NULL; |
| 343 | struct fname * fname, *new_fn; |
| 344 | struct dir_private_info *info; |
| 345 | int len; |
| 346 | |
| 347 | info = (struct dir_private_info *) dir_file->private_data; |
| 348 | p = &info->root.rb_node; |
| 349 | |
| 350 | /* Create and allocate the fname structure */ |
| 351 | len = sizeof(struct fname) + dirent->name_len + 1; |
| 352 | new_fn = kzalloc(len, GFP_KERNEL); |
| 353 | if (!new_fn) |
| 354 | return -ENOMEM; |
| 355 | new_fn->hash = hash; |
| 356 | new_fn->minor_hash = minor_hash; |
| 357 | new_fn->inode = le32_to_cpu(dirent->inode); |
| 358 | new_fn->name_len = dirent->name_len; |
| 359 | new_fn->file_type = dirent->file_type; |
| 360 | memcpy(new_fn->name, dirent->name, dirent->name_len); |
| 361 | new_fn->name[dirent->name_len] = 0; |
| 362 | |
| 363 | while (*p) { |
| 364 | parent = *p; |
| 365 | fname = rb_entry(parent, struct fname, rb_hash); |
| 366 | |
| 367 | /* |
| 368 | * If the hash and minor hash match up, then we put |
| 369 | * them on a linked list. This rarely happens... |
| 370 | */ |
| 371 | if ((new_fn->hash == fname->hash) && |
| 372 | (new_fn->minor_hash == fname->minor_hash)) { |
| 373 | new_fn->next = fname->next; |
| 374 | fname->next = new_fn; |
| 375 | return 0; |
| 376 | } |
| 377 | |
| 378 | if (new_fn->hash < fname->hash) |
| 379 | p = &(*p)->rb_left; |
| 380 | else if (new_fn->hash > fname->hash) |
| 381 | p = &(*p)->rb_right; |
| 382 | else if (new_fn->minor_hash < fname->minor_hash) |
| 383 | p = &(*p)->rb_left; |
| 384 | else /* if (new_fn->minor_hash > fname->minor_hash) */ |
| 385 | p = &(*p)->rb_right; |
| 386 | } |
| 387 | |
| 388 | rb_link_node(&new_fn->rb_hash, parent, p); |
| 389 | rb_insert_color(&new_fn->rb_hash, &info->root); |
| 390 | return 0; |
| 391 | } |
| 392 | |
| 393 | |
| 394 | |
| 395 | /* |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 396 | * This is a helper function for ext4_dx_readdir. It calls filldir |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 397 | * for all entres on the fname linked list. (Normally there is only |
| 398 | * one entry on the linked list, unless there are 62 bit hash collisions.) |
| 399 | */ |
| 400 | static int call_filldir(struct file * filp, void * dirent, |
| 401 | filldir_t filldir, struct fname *fname) |
| 402 | { |
| 403 | struct dir_private_info *info = filp->private_data; |
| 404 | loff_t curr_pos; |
Josef "Jeff" Sipek | 9d54989 | 2006-12-08 02:36:38 -0800 | [diff] [blame^] | 405 | struct inode *inode = filp->f_path.dentry->d_inode; |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 406 | struct super_block * sb; |
| 407 | int error; |
| 408 | |
| 409 | sb = inode->i_sb; |
| 410 | |
| 411 | if (!fname) { |
| 412 | printk("call_filldir: called with null fname?!?\n"); |
| 413 | return 0; |
| 414 | } |
| 415 | curr_pos = hash2pos(fname->hash, fname->minor_hash); |
| 416 | while (fname) { |
| 417 | error = filldir(dirent, fname->name, |
| 418 | fname->name_len, curr_pos, |
| 419 | fname->inode, |
| 420 | get_dtype(sb, fname->file_type)); |
| 421 | if (error) { |
| 422 | filp->f_pos = curr_pos; |
| 423 | info->extra_fname = fname->next; |
| 424 | return error; |
| 425 | } |
| 426 | fname = fname->next; |
| 427 | } |
| 428 | return 0; |
| 429 | } |
| 430 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 431 | static int ext4_dx_readdir(struct file * filp, |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 432 | void * dirent, filldir_t filldir) |
| 433 | { |
| 434 | struct dir_private_info *info = filp->private_data; |
Josef "Jeff" Sipek | 9d54989 | 2006-12-08 02:36:38 -0800 | [diff] [blame^] | 435 | struct inode *inode = filp->f_path.dentry->d_inode; |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 436 | struct fname *fname; |
| 437 | int ret; |
| 438 | |
| 439 | if (!info) { |
| 440 | info = create_dir_info(filp->f_pos); |
| 441 | if (!info) |
| 442 | return -ENOMEM; |
| 443 | filp->private_data = info; |
| 444 | } |
| 445 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 446 | if (filp->f_pos == EXT4_HTREE_EOF) |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 447 | return 0; /* EOF */ |
| 448 | |
| 449 | /* Some one has messed with f_pos; reset the world */ |
| 450 | if (info->last_pos != filp->f_pos) { |
| 451 | free_rb_tree_fname(&info->root); |
| 452 | info->curr_node = NULL; |
| 453 | info->extra_fname = NULL; |
| 454 | info->curr_hash = pos2maj_hash(filp->f_pos); |
| 455 | info->curr_minor_hash = pos2min_hash(filp->f_pos); |
| 456 | } |
| 457 | |
| 458 | /* |
| 459 | * If there are any leftover names on the hash collision |
| 460 | * chain, return them first. |
| 461 | */ |
| 462 | if (info->extra_fname && |
| 463 | call_filldir(filp, dirent, filldir, info->extra_fname)) |
| 464 | goto finished; |
| 465 | |
| 466 | if (!info->curr_node) |
| 467 | info->curr_node = rb_first(&info->root); |
| 468 | |
| 469 | while (1) { |
| 470 | /* |
| 471 | * Fill the rbtree if we have no more entries, |
| 472 | * or the inode has changed since we last read in the |
| 473 | * cached entries. |
| 474 | */ |
| 475 | if ((!info->curr_node) || |
| 476 | (filp->f_version != inode->i_version)) { |
| 477 | info->curr_node = NULL; |
| 478 | free_rb_tree_fname(&info->root); |
| 479 | filp->f_version = inode->i_version; |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 480 | ret = ext4_htree_fill_tree(filp, info->curr_hash, |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 481 | info->curr_minor_hash, |
| 482 | &info->next_hash); |
| 483 | if (ret < 0) |
| 484 | return ret; |
| 485 | if (ret == 0) { |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 486 | filp->f_pos = EXT4_HTREE_EOF; |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 487 | break; |
| 488 | } |
| 489 | info->curr_node = rb_first(&info->root); |
| 490 | } |
| 491 | |
| 492 | fname = rb_entry(info->curr_node, struct fname, rb_hash); |
| 493 | info->curr_hash = fname->hash; |
| 494 | info->curr_minor_hash = fname->minor_hash; |
| 495 | if (call_filldir(filp, dirent, filldir, fname)) |
| 496 | break; |
| 497 | |
| 498 | info->curr_node = rb_next(info->curr_node); |
| 499 | if (!info->curr_node) { |
| 500 | if (info->next_hash == ~0) { |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 501 | filp->f_pos = EXT4_HTREE_EOF; |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 502 | break; |
| 503 | } |
| 504 | info->curr_hash = info->next_hash; |
| 505 | info->curr_minor_hash = 0; |
| 506 | } |
| 507 | } |
| 508 | finished: |
| 509 | info->last_pos = filp->f_pos; |
| 510 | return 0; |
| 511 | } |
| 512 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 513 | static int ext4_release_dir (struct inode * inode, struct file * filp) |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 514 | { |
Andrew Morton | 63f5793 | 2006-10-11 01:21:24 -0700 | [diff] [blame] | 515 | if (filp->private_data) |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 516 | ext4_htree_free_dir_info(filp->private_data); |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 517 | |
| 518 | return 0; |
| 519 | } |
| 520 | |
| 521 | #endif |