Root/fs/ext4/namei.c

1/*
2 * linux/fs/ext4/namei.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/namei.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Big-endian to little-endian byte-swapping/bitmaps by
16 * David S. Miller (davem@caip.rutgers.edu), 1995
17 * Directory entry file type support and forward compatibility hooks
18 * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
19 * Hash Tree Directory indexing (c)
20 * Daniel Phillips, 2001
21 * Hash Tree Directory indexing porting
22 * Christopher Li, 2002
23 * Hash Tree Directory indexing cleanup
24 * Theodore Ts'o, 2002
25 */
26
27#include <linux/fs.h>
28#include <linux/pagemap.h>
29#include <linux/jbd2.h>
30#include <linux/time.h>
31#include <linux/fcntl.h>
32#include <linux/stat.h>
33#include <linux/string.h>
34#include <linux/quotaops.h>
35#include <linux/buffer_head.h>
36#include <linux/bio.h>
37#include "ext4.h"
38#include "ext4_jbd2.h"
39
40#include "xattr.h"
41#include "acl.h"
42
43/*
44 * define how far ahead to read directories while searching them.
45 */
46#define NAMEI_RA_CHUNKS 2
47#define NAMEI_RA_BLOCKS 4
48#define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
49#define NAMEI_RA_INDEX(c,b) (((c) * NAMEI_RA_BLOCKS) + (b))
50
51static struct buffer_head *ext4_append(handle_t *handle,
52                    struct inode *inode,
53                    ext4_lblk_t *block, int *err)
54{
55    struct buffer_head *bh;
56
57    *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
58
59    bh = ext4_bread(handle, inode, *block, 1, err);
60    if (bh) {
61        inode->i_size += inode->i_sb->s_blocksize;
62        EXT4_I(inode)->i_disksize = inode->i_size;
63        *err = ext4_journal_get_write_access(handle, bh);
64        if (*err) {
65            brelse(bh);
66            bh = NULL;
67        }
68    }
69    return bh;
70}
71
72#ifndef assert
73#define assert(test) J_ASSERT(test)
74#endif
75
76#ifdef DX_DEBUG
77#define dxtrace(command) command
78#else
79#define dxtrace(command)
80#endif
81
82struct fake_dirent
83{
84    __le32 inode;
85    __le16 rec_len;
86    u8 name_len;
87    u8 file_type;
88};
89
90struct dx_countlimit
91{
92    __le16 limit;
93    __le16 count;
94};
95
96struct dx_entry
97{
98    __le32 hash;
99    __le32 block;
100};
101
102/*
103 * dx_root_info is laid out so that if it should somehow get overlaid by a
104 * dirent the two low bits of the hash version will be zero. Therefore, the
105 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
106 */
107
108struct dx_root
109{
110    struct fake_dirent dot;
111    char dot_name[4];
112    struct fake_dirent dotdot;
113    char dotdot_name[4];
114    struct dx_root_info
115    {
116        __le32 reserved_zero;
117        u8 hash_version;
118        u8 info_length; /* 8 */
119        u8 indirect_levels;
120        u8 unused_flags;
121    }
122    info;
123    struct dx_entry entries[0];
124};
125
126struct dx_node
127{
128    struct fake_dirent fake;
129    struct dx_entry entries[0];
130};
131
132
133struct dx_frame
134{
135    struct buffer_head *bh;
136    struct dx_entry *entries;
137    struct dx_entry *at;
138};
139
140struct dx_map_entry
141{
142    u32 hash;
143    u16 offs;
144    u16 size;
145};
146
147static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
148static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
149static inline unsigned dx_get_hash(struct dx_entry *entry);
150static void dx_set_hash(struct dx_entry *entry, unsigned value);
151static unsigned dx_get_count(struct dx_entry *entries);
152static unsigned dx_get_limit(struct dx_entry *entries);
153static void dx_set_count(struct dx_entry *entries, unsigned value);
154static void dx_set_limit(struct dx_entry *entries, unsigned value);
155static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
156static unsigned dx_node_limit(struct inode *dir);
157static struct dx_frame *dx_probe(const struct qstr *d_name,
158                 struct inode *dir,
159                 struct dx_hash_info *hinfo,
160                 struct dx_frame *frame,
161                 int *err);
162static void dx_release(struct dx_frame *frames);
163static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
164               struct dx_hash_info *hinfo, struct dx_map_entry map[]);
165static void dx_sort_map(struct dx_map_entry *map, unsigned count);
166static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
167        struct dx_map_entry *offsets, int count, unsigned blocksize);
168static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
169static void dx_insert_block(struct dx_frame *frame,
170                    u32 hash, ext4_lblk_t block);
171static int ext4_htree_next_block(struct inode *dir, __u32 hash,
172                 struct dx_frame *frame,
173                 struct dx_frame *frames,
174                 __u32 *start_hash);
175static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
176        const struct qstr *d_name,
177        struct ext4_dir_entry_2 **res_dir,
178        int *err);
179static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
180                 struct inode *inode);
181
182unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
183{
184    unsigned len = le16_to_cpu(dlen);
185
186    if (len == EXT4_MAX_REC_LEN || len == 0)
187        return blocksize;
188    return (len & 65532) | ((len & 3) << 16);
189}
190  
191__le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
192{
193    if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
194        BUG();
195    if (len < 65536)
196        return cpu_to_le16(len);
197    if (len == blocksize) {
198        if (blocksize == 65536)
199            return cpu_to_le16(EXT4_MAX_REC_LEN);
200        else
201            return cpu_to_le16(0);
202    }
203    return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
204}
205
206/*
207 * p is at least 6 bytes before the end of page
208 */
209static inline struct ext4_dir_entry_2 *
210ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
211{
212    return (struct ext4_dir_entry_2 *)((char *)p +
213        ext4_rec_len_from_disk(p->rec_len, blocksize));
214}
215
216/*
217 * Future: use high four bits of block for coalesce-on-delete flags
218 * Mask them off for now.
219 */
220
221static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
222{
223    return le32_to_cpu(entry->block) & 0x00ffffff;
224}
225
226static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
227{
228    entry->block = cpu_to_le32(value);
229}
230
231static inline unsigned dx_get_hash(struct dx_entry *entry)
232{
233    return le32_to_cpu(entry->hash);
234}
235
236static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
237{
238    entry->hash = cpu_to_le32(value);
239}
240
241static inline unsigned dx_get_count(struct dx_entry *entries)
242{
243    return le16_to_cpu(((struct dx_countlimit *) entries)->count);
244}
245
246static inline unsigned dx_get_limit(struct dx_entry *entries)
247{
248    return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
249}
250
251static inline void dx_set_count(struct dx_entry *entries, unsigned value)
252{
253    ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
254}
255
256static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
257{
258    ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
259}
260
261static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
262{
263    unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
264        EXT4_DIR_REC_LEN(2) - infosize;
265    return entry_space / sizeof(struct dx_entry);
266}
267
268static inline unsigned dx_node_limit(struct inode *dir)
269{
270    unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
271    return entry_space / sizeof(struct dx_entry);
272}
273
274/*
275 * Debug
276 */
277#ifdef DX_DEBUG
278static void dx_show_index(char * label, struct dx_entry *entries)
279{
280    int i, n = dx_get_count (entries);
281    printk(KERN_DEBUG "%s index ", label);
282    for (i = 0; i < n; i++) {
283        printk("%x->%lu ", i ? dx_get_hash(entries + i) :
284                0, (unsigned long)dx_get_block(entries + i));
285    }
286    printk("\n");
287}
288
289struct stats
290{
291    unsigned names;
292    unsigned space;
293    unsigned bcount;
294};
295
296static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
297                 int size, int show_names)
298{
299    unsigned names = 0, space = 0;
300    char *base = (char *) de;
301    struct dx_hash_info h = *hinfo;
302
303    printk("names: ");
304    while ((char *) de < base + size)
305    {
306        if (de->inode)
307        {
308            if (show_names)
309            {
310                int len = de->name_len;
311                char *name = de->name;
312                while (len--) printk("%c", *name++);
313                ext4fs_dirhash(de->name, de->name_len, &h);
314                printk(":%x.%u ", h.hash,
315                       ((char *) de - base));
316            }
317            space += EXT4_DIR_REC_LEN(de->name_len);
318            names++;
319        }
320        de = ext4_next_entry(de, size);
321    }
322    printk("(%i)\n", names);
323    return (struct stats) { names, space, 1 };
324}
325
326struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
327                 struct dx_entry *entries, int levels)
328{
329    unsigned blocksize = dir->i_sb->s_blocksize;
330    unsigned count = dx_get_count(entries), names = 0, space = 0, i;
331    unsigned bcount = 0;
332    struct buffer_head *bh;
333    int err;
334    printk("%i indexed blocks...\n", count);
335    for (i = 0; i < count; i++, entries++)
336    {
337        ext4_lblk_t block = dx_get_block(entries);
338        ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
339        u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
340        struct stats stats;
341        printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
342        if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
343        stats = levels?
344           dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
345           dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
346        names += stats.names;
347        space += stats.space;
348        bcount += stats.bcount;
349        brelse(bh);
350    }
351    if (bcount)
352        printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
353               levels ? "" : " ", names, space/bcount,
354               (space/bcount)*100/blocksize);
355    return (struct stats) { names, space, bcount};
356}
357#endif /* DX_DEBUG */
358
359/*
360 * Probe for a directory leaf block to search.
361 *
362 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
363 * error in the directory index, and the caller should fall back to
364 * searching the directory normally. The callers of dx_probe **MUST**
365 * check for this error code, and make sure it never gets reflected
366 * back to userspace.
367 */
368static struct dx_frame *
369dx_probe(const struct qstr *d_name, struct inode *dir,
370     struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
371{
372    unsigned count, indirect;
373    struct dx_entry *at, *entries, *p, *q, *m;
374    struct dx_root *root;
375    struct buffer_head *bh;
376    struct dx_frame *frame = frame_in;
377    u32 hash;
378
379    frame->bh = NULL;
380    if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
381        goto fail;
382    root = (struct dx_root *) bh->b_data;
383    if (root->info.hash_version != DX_HASH_TEA &&
384        root->info.hash_version != DX_HASH_HALF_MD4 &&
385        root->info.hash_version != DX_HASH_LEGACY) {
386        ext4_warning(dir->i_sb, __func__,
387                 "Unrecognised inode hash code %d",
388                 root->info.hash_version);
389        brelse(bh);
390        *err = ERR_BAD_DX_DIR;
391        goto fail;
392    }
393    hinfo->hash_version = root->info.hash_version;
394    if (hinfo->hash_version <= DX_HASH_TEA)
395        hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
396    hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
397    if (d_name)
398        ext4fs_dirhash(d_name->name, d_name->len, hinfo);
399    hash = hinfo->hash;
400
401    if (root->info.unused_flags & 1) {
402        ext4_warning(dir->i_sb, __func__,
403                 "Unimplemented inode hash flags: %#06x",
404                 root->info.unused_flags);
405        brelse(bh);
406        *err = ERR_BAD_DX_DIR;
407        goto fail;
408    }
409
410    if ((indirect = root->info.indirect_levels) > 1) {
411        ext4_warning(dir->i_sb, __func__,
412                 "Unimplemented inode hash depth: %#06x",
413                 root->info.indirect_levels);
414        brelse(bh);
415        *err = ERR_BAD_DX_DIR;
416        goto fail;
417    }
418
419    entries = (struct dx_entry *) (((char *)&root->info) +
420                       root->info.info_length);
421
422    if (dx_get_limit(entries) != dx_root_limit(dir,
423                           root->info.info_length)) {
424        ext4_warning(dir->i_sb, __func__,
425                 "dx entry: limit != root limit");
426        brelse(bh);
427        *err = ERR_BAD_DX_DIR;
428        goto fail;
429    }
430
431    dxtrace(printk("Look up %x", hash));
432    while (1)
433    {
434        count = dx_get_count(entries);
435        if (!count || count > dx_get_limit(entries)) {
436            ext4_warning(dir->i_sb, __func__,
437                     "dx entry: no count or count > limit");
438            brelse(bh);
439            *err = ERR_BAD_DX_DIR;
440            goto fail2;
441        }
442
443        p = entries + 1;
444        q = entries + count - 1;
445        while (p <= q)
446        {
447            m = p + (q - p)/2;
448            dxtrace(printk("."));
449            if (dx_get_hash(m) > hash)
450                q = m - 1;
451            else
452                p = m + 1;
453        }
454
455        if (0) // linear search cross check
456        {
457            unsigned n = count - 1;
458            at = entries;
459            while (n--)
460            {
461                dxtrace(printk(","));
462                if (dx_get_hash(++at) > hash)
463                {
464                    at--;
465                    break;
466                }
467            }
468            assert (at == p - 1);
469        }
470
471        at = p - 1;
472        dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
473        frame->bh = bh;
474        frame->entries = entries;
475        frame->at = at;
476        if (!indirect--) return frame;
477        if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
478            goto fail2;
479        at = entries = ((struct dx_node *) bh->b_data)->entries;
480        if (dx_get_limit(entries) != dx_node_limit (dir)) {
481            ext4_warning(dir->i_sb, __func__,
482                     "dx entry: limit != node limit");
483            brelse(bh);
484            *err = ERR_BAD_DX_DIR;
485            goto fail2;
486        }
487        frame++;
488        frame->bh = NULL;
489    }
490fail2:
491    while (frame >= frame_in) {
492        brelse(frame->bh);
493        frame--;
494    }
495fail:
496    if (*err == ERR_BAD_DX_DIR)
497        ext4_warning(dir->i_sb, __func__,
498                 "Corrupt dir inode %ld, running e2fsck is "
499                 "recommended.", dir->i_ino);
500    return NULL;
501}
502
503static void dx_release (struct dx_frame *frames)
504{
505    if (frames[0].bh == NULL)
506        return;
507
508    if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
509        brelse(frames[1].bh);
510    brelse(frames[0].bh);
511}
512
513/*
514 * This function increments the frame pointer to search the next leaf
515 * block, and reads in the necessary intervening nodes if the search
516 * should be necessary. Whether or not the search is necessary is
517 * controlled by the hash parameter. If the hash value is even, then
518 * the search is only continued if the next block starts with that
519 * hash value. This is used if we are searching for a specific file.
520 *
521 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
522 *
523 * This function returns 1 if the caller should continue to search,
524 * or 0 if it should not. If there is an error reading one of the
525 * index blocks, it will a negative error code.
526 *
527 * If start_hash is non-null, it will be filled in with the starting
528 * hash of the next page.
529 */
530static int ext4_htree_next_block(struct inode *dir, __u32 hash,
531                 struct dx_frame *frame,
532                 struct dx_frame *frames,
533                 __u32 *start_hash)
534{
535    struct dx_frame *p;
536    struct buffer_head *bh;
537    int err, num_frames = 0;
538    __u32 bhash;
539
540    p = frame;
541    /*
542     * Find the next leaf page by incrementing the frame pointer.
543     * If we run out of entries in the interior node, loop around and
544     * increment pointer in the parent node. When we break out of
545     * this loop, num_frames indicates the number of interior
546     * nodes need to be read.
547     */
548    while (1) {
549        if (++(p->at) < p->entries + dx_get_count(p->entries))
550            break;
551        if (p == frames)
552            return 0;
553        num_frames++;
554        p--;
555    }
556
557    /*
558     * If the hash is 1, then continue only if the next page has a
559     * continuation hash of any value. This is used for readdir
560     * handling. Otherwise, check to see if the hash matches the
561     * desired contiuation hash. If it doesn't, return since
562     * there's no point to read in the successive index pages.
563     */
564    bhash = dx_get_hash(p->at);
565    if (start_hash)
566        *start_hash = bhash;
567    if ((hash & 1) == 0) {
568        if ((bhash & ~1) != hash)
569            return 0;
570    }
571    /*
572     * If the hash is HASH_NB_ALWAYS, we always go to the next
573     * block so no check is necessary
574     */
575    while (num_frames--) {
576        if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
577                      0, &err)))
578            return err; /* Failure */
579        p++;
580        brelse(p->bh);
581        p->bh = bh;
582        p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
583    }
584    return 1;
585}
586
587
588/*
589 * This function fills a red-black tree with information from a
590 * directory block. It returns the number directory entries loaded
591 * into the tree. If there is an error it is returned in err.
592 */
593static int htree_dirblock_to_tree(struct file *dir_file,
594                  struct inode *dir, ext4_lblk_t block,
595                  struct dx_hash_info *hinfo,
596                  __u32 start_hash, __u32 start_minor_hash)
597{
598    struct buffer_head *bh;
599    struct ext4_dir_entry_2 *de, *top;
600    int err, count = 0;
601
602    dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
603                            (unsigned long)block));
604    if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
605        return err;
606
607    de = (struct ext4_dir_entry_2 *) bh->b_data;
608    top = (struct ext4_dir_entry_2 *) ((char *) de +
609                       dir->i_sb->s_blocksize -
610                       EXT4_DIR_REC_LEN(0));
611    for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
612        if (!ext4_check_dir_entry("htree_dirblock_to_tree", dir, de, bh,
613                    (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
614                        +((char *)de - bh->b_data))) {
615            /* On error, skip the f_pos to the next block. */
616            dir_file->f_pos = (dir_file->f_pos |
617                    (dir->i_sb->s_blocksize - 1)) + 1;
618            brelse(bh);
619            return count;
620        }
621        ext4fs_dirhash(de->name, de->name_len, hinfo);
622        if ((hinfo->hash < start_hash) ||
623            ((hinfo->hash == start_hash) &&
624             (hinfo->minor_hash < start_minor_hash)))
625            continue;
626        if (de->inode == 0)
627            continue;
628        if ((err = ext4_htree_store_dirent(dir_file,
629                   hinfo->hash, hinfo->minor_hash, de)) != 0) {
630            brelse(bh);
631            return err;
632        }
633        count++;
634    }
635    brelse(bh);
636    return count;
637}
638
639
640/*
641 * This function fills a red-black tree with information from a
642 * directory. We start scanning the directory in hash order, starting
643 * at start_hash and start_minor_hash.
644 *
645 * This function returns the number of entries inserted into the tree,
646 * or a negative error code.
647 */
648int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
649             __u32 start_minor_hash, __u32 *next_hash)
650{
651    struct dx_hash_info hinfo;
652    struct ext4_dir_entry_2 *de;
653    struct dx_frame frames[2], *frame;
654    struct inode *dir;
655    ext4_lblk_t block;
656    int count = 0;
657    int ret, err;
658    __u32 hashval;
659
660    dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
661               start_hash, start_minor_hash));
662    dir = dir_file->f_path.dentry->d_inode;
663    if (!(EXT4_I(dir)->i_flags & EXT4_INDEX_FL)) {
664        hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
665        if (hinfo.hash_version <= DX_HASH_TEA)
666            hinfo.hash_version +=
667                EXT4_SB(dir->i_sb)->s_hash_unsigned;
668        hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
669        count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
670                           start_hash, start_minor_hash);
671        *next_hash = ~0;
672        return count;
673    }
674    hinfo.hash = start_hash;
675    hinfo.minor_hash = 0;
676    frame = dx_probe(NULL, dir, &hinfo, frames, &err);
677    if (!frame)
678        return err;
679
680    /* Add '.' and '..' from the htree header */
681    if (!start_hash && !start_minor_hash) {
682        de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
683        if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
684            goto errout;
685        count++;
686    }
687    if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
688        de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
689        de = ext4_next_entry(de, dir->i_sb->s_blocksize);
690        if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
691            goto errout;
692        count++;
693    }
694
695    while (1) {
696        block = dx_get_block(frame->at);
697        ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
698                         start_hash, start_minor_hash);
699        if (ret < 0) {
700            err = ret;
701            goto errout;
702        }
703        count += ret;
704        hashval = ~0;
705        ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
706                        frame, frames, &hashval);
707        *next_hash = hashval;
708        if (ret < 0) {
709            err = ret;
710            goto errout;
711        }
712        /*
713         * Stop if: (a) there are no more entries, or
714         * (b) we have inserted at least one entry and the
715         * next hash value is not a continuation
716         */
717        if ((ret == 0) ||
718            (count && ((hashval & 1) == 0)))
719            break;
720    }
721    dx_release(frames);
722    dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
723               "next hash: %x\n", count, *next_hash));
724    return count;
725errout:
726    dx_release(frames);
727    return (err);
728}
729
730
731/*
732 * Directory block splitting, compacting
733 */
734
735/*
736 * Create map of hash values, offsets, and sizes, stored at end of block.
737 * Returns number of entries mapped.
738 */
739static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
740               struct dx_hash_info *hinfo,
741               struct dx_map_entry *map_tail)
742{
743    int count = 0;
744    char *base = (char *) de;
745    struct dx_hash_info h = *hinfo;
746
747    while ((char *) de < base + blocksize) {
748        if (de->name_len && de->inode) {
749            ext4fs_dirhash(de->name, de->name_len, &h);
750            map_tail--;
751            map_tail->hash = h.hash;
752            map_tail->offs = ((char *) de - base)>>2;
753            map_tail->size = le16_to_cpu(de->rec_len);
754            count++;
755            cond_resched();
756        }
757        /* XXX: do we need to check rec_len == 0 case? -Chris */
758        de = ext4_next_entry(de, blocksize);
759    }
760    return count;
761}
762
763/* Sort map by hash value */
764static void dx_sort_map (struct dx_map_entry *map, unsigned count)
765{
766    struct dx_map_entry *p, *q, *top = map + count - 1;
767    int more;
768    /* Combsort until bubble sort doesn't suck */
769    while (count > 2) {
770        count = count*10/13;
771        if (count - 9 < 2) /* 9, 10 -> 11 */
772            count = 11;
773        for (p = top, q = p - count; q >= map; p--, q--)
774            if (p->hash < q->hash)
775                swap(*p, *q);
776    }
777    /* Garden variety bubble sort */
778    do {
779        more = 0;
780        q = top;
781        while (q-- > map) {
782            if (q[1].hash >= q[0].hash)
783                continue;
784            swap(*(q+1), *q);
785            more = 1;
786        }
787    } while(more);
788}
789
790static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
791{
792    struct dx_entry *entries = frame->entries;
793    struct dx_entry *old = frame->at, *new = old + 1;
794    int count = dx_get_count(entries);
795
796    assert(count < dx_get_limit(entries));
797    assert(old < entries + count);
798    memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
799    dx_set_hash(new, hash);
800    dx_set_block(new, block);
801    dx_set_count(entries, count + 1);
802}
803
804static void ext4_update_dx_flag(struct inode *inode)
805{
806    if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
807                     EXT4_FEATURE_COMPAT_DIR_INDEX))
808        EXT4_I(inode)->i_flags &= ~EXT4_INDEX_FL;
809}
810
811/*
812 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
813 *
814 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
815 * `de != NULL' is guaranteed by caller.
816 */
817static inline int ext4_match (int len, const char * const name,
818                  struct ext4_dir_entry_2 * de)
819{
820    if (len != de->name_len)
821        return 0;
822    if (!de->inode)
823        return 0;
824    return !memcmp(name, de->name, len);
825}
826
827/*
828 * Returns 0 if not found, -1 on failure, and 1 on success
829 */
830static inline int search_dirblock(struct buffer_head *bh,
831                  struct inode *dir,
832                  const struct qstr *d_name,
833                  unsigned int offset,
834                  struct ext4_dir_entry_2 ** res_dir)
835{
836    struct ext4_dir_entry_2 * de;
837    char * dlimit;
838    int de_len;
839    const char *name = d_name->name;
840    int namelen = d_name->len;
841
842    de = (struct ext4_dir_entry_2 *) bh->b_data;
843    dlimit = bh->b_data + dir->i_sb->s_blocksize;
844    while ((char *) de < dlimit) {
845        /* this code is executed quadratically often */
846        /* do minimal checking `by hand' */
847
848        if ((char *) de + namelen <= dlimit &&
849            ext4_match (namelen, name, de)) {
850            /* found a match - just to be sure, do a full check */
851            if (!ext4_check_dir_entry("ext4_find_entry",
852                          dir, de, bh, offset))
853                return -1;
854            *res_dir = de;
855            return 1;
856        }
857        /* prevent looping on a bad block */
858        de_len = ext4_rec_len_from_disk(de->rec_len,
859                        dir->i_sb->s_blocksize);
860        if (de_len <= 0)
861            return -1;
862        offset += de_len;
863        de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
864    }
865    return 0;
866}
867
868
869/*
870 * ext4_find_entry()
871 *
872 * finds an entry in the specified directory with the wanted name. It
873 * returns the cache buffer in which the entry was found, and the entry
874 * itself (as a parameter - res_dir). It does NOT read the inode of the
875 * entry - you'll have to do that yourself if you want to.
876 *
877 * The returned buffer_head has ->b_count elevated. The caller is expected
878 * to brelse() it when appropriate.
879 */
880static struct buffer_head * ext4_find_entry (struct inode *dir,
881                    const struct qstr *d_name,
882                    struct ext4_dir_entry_2 ** res_dir)
883{
884    struct super_block *sb;
885    struct buffer_head *bh_use[NAMEI_RA_SIZE];
886    struct buffer_head *bh, *ret = NULL;
887    ext4_lblk_t start, block, b;
888    int ra_max = 0; /* Number of bh's in the readahead
889                   buffer, bh_use[] */
890    int ra_ptr = 0; /* Current index into readahead
891                   buffer */
892    int num = 0;
893    ext4_lblk_t nblocks;
894    int i, err;
895    int namelen;
896
897    *res_dir = NULL;
898    sb = dir->i_sb;
899    namelen = d_name->len;
900    if (namelen > EXT4_NAME_LEN)
901        return NULL;
902    if (is_dx(dir)) {
903        bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
904        /*
905         * On success, or if the error was file not found,
906         * return. Otherwise, fall back to doing a search the
907         * old fashioned way.
908         */
909        if (bh || (err != ERR_BAD_DX_DIR))
910            return bh;
911        dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
912                   "falling back\n"));
913    }
914    nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
915    start = EXT4_I(dir)->i_dir_start_lookup;
916    if (start >= nblocks)
917        start = 0;
918    block = start;
919restart:
920    do {
921        /*
922         * We deal with the read-ahead logic here.
923         */
924        if (ra_ptr >= ra_max) {
925            /* Refill the readahead buffer */
926            ra_ptr = 0;
927            b = block;
928            for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
929                /*
930                 * Terminate if we reach the end of the
931                 * directory and must wrap, or if our
932                 * search has finished at this block.
933                 */
934                if (b >= nblocks || (num && block == start)) {
935                    bh_use[ra_max] = NULL;
936                    break;
937                }
938                num++;
939                bh = ext4_getblk(NULL, dir, b++, 0, &err);
940                bh_use[ra_max] = bh;
941                if (bh)
942                    ll_rw_block(READ_META, 1, &bh);
943            }
944        }
945        if ((bh = bh_use[ra_ptr++]) == NULL)
946            goto next;
947        wait_on_buffer(bh);
948        if (!buffer_uptodate(bh)) {
949            /* read error, skip block & hope for the best */
950            ext4_error(sb, __func__, "reading directory #%lu "
951                   "offset %lu", dir->i_ino,
952                   (unsigned long)block);
953            brelse(bh);
954            goto next;
955        }
956        i = search_dirblock(bh, dir, d_name,
957                block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
958        if (i == 1) {
959            EXT4_I(dir)->i_dir_start_lookup = block;
960            ret = bh;
961            goto cleanup_and_exit;
962        } else {
963            brelse(bh);
964            if (i < 0)
965                goto cleanup_and_exit;
966        }
967    next:
968        if (++block >= nblocks)
969            block = 0;
970    } while (block != start);
971
972    /*
973     * If the directory has grown while we were searching, then
974     * search the last part of the directory before giving up.
975     */
976    block = nblocks;
977    nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
978    if (block < nblocks) {
979        start = 0;
980        goto restart;
981    }
982
983cleanup_and_exit:
984    /* Clean up the read-ahead blocks */
985    for (; ra_ptr < ra_max; ra_ptr++)
986        brelse(bh_use[ra_ptr]);
987    return ret;
988}
989
990static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
991               struct ext4_dir_entry_2 **res_dir, int *err)
992{
993    struct super_block * sb;
994    struct dx_hash_info hinfo;
995    u32 hash;
996    struct dx_frame frames[2], *frame;
997    struct ext4_dir_entry_2 *de, *top;
998    struct buffer_head *bh;
999    ext4_lblk_t block;
1000    int retval;
1001    int namelen = d_name->len;
1002    const u8 *name = d_name->name;
1003
1004    sb = dir->i_sb;
1005    /* NFS may look up ".." - look at dx_root directory block */
1006    if (namelen > 2 || name[0] != '.'||(name[1] != '.' && name[1] != '\0')){
1007        if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
1008            return NULL;
1009    } else {
1010        frame = frames;
1011        frame->bh = NULL; /* for dx_release() */
1012        frame->at = (struct dx_entry *)frames; /* hack for zero entry*/
1013        dx_set_block(frame->at, 0); /* dx_root block is 0 */
1014    }
1015    hash = hinfo.hash;
1016    do {
1017        block = dx_get_block(frame->at);
1018        if (!(bh = ext4_bread (NULL,dir, block, 0, err)))
1019            goto errout;
1020        de = (struct ext4_dir_entry_2 *) bh->b_data;
1021        top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize -
1022                       EXT4_DIR_REC_LEN(0));
1023        for (; de < top; de = ext4_next_entry(de, sb->s_blocksize)) {
1024            int off = (block << EXT4_BLOCK_SIZE_BITS(sb))
1025                  + ((char *) de - bh->b_data);
1026
1027            if (!ext4_check_dir_entry(__func__, dir, de, bh, off)) {
1028                brelse(bh);
1029                *err = ERR_BAD_DX_DIR;
1030                goto errout;
1031            }
1032
1033            if (ext4_match(namelen, name, de)) {
1034                *res_dir = de;
1035                dx_release(frames);
1036                return bh;
1037            }
1038        }
1039        brelse(bh);
1040        /* Check to see if we should continue to search */
1041        retval = ext4_htree_next_block(dir, hash, frame,
1042                           frames, NULL);
1043        if (retval < 0) {
1044            ext4_warning(sb, __func__,
1045                 "error reading index page in directory #%lu",
1046                 dir->i_ino);
1047            *err = retval;
1048            goto errout;
1049        }
1050    } while (retval == 1);
1051
1052    *err = -ENOENT;
1053errout:
1054    dxtrace(printk(KERN_DEBUG "%s not found\n", name));
1055    dx_release (frames);
1056    return NULL;
1057}
1058
1059static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
1060{
1061    struct inode *inode;
1062    struct ext4_dir_entry_2 *de;
1063    struct buffer_head *bh;
1064
1065    if (dentry->d_name.len > EXT4_NAME_LEN)
1066        return ERR_PTR(-ENAMETOOLONG);
1067
1068    bh = ext4_find_entry(dir, &dentry->d_name, &de);
1069    inode = NULL;
1070    if (bh) {
1071        __u32 ino = le32_to_cpu(de->inode);
1072        brelse(bh);
1073        if (!ext4_valid_inum(dir->i_sb, ino)) {
1074            ext4_error(dir->i_sb, "ext4_lookup",
1075                   "bad inode number: %u", ino);
1076            return ERR_PTR(-EIO);
1077        }
1078        inode = ext4_iget(dir->i_sb, ino);
1079        if (unlikely(IS_ERR(inode))) {
1080            if (PTR_ERR(inode) == -ESTALE) {
1081                ext4_error(dir->i_sb, __func__,
1082                        "deleted inode referenced: %u",
1083                        ino);
1084                return ERR_PTR(-EIO);
1085            } else {
1086                return ERR_CAST(inode);
1087            }
1088        }
1089    }
1090    return d_splice_alias(inode, dentry);
1091}
1092
1093
1094struct dentry *ext4_get_parent(struct dentry *child)
1095{
1096    __u32 ino;
1097    struct inode *inode;
1098    static const struct qstr dotdot = {
1099        .name = "..",
1100        .len = 2,
1101    };
1102    struct ext4_dir_entry_2 * de;
1103    struct buffer_head *bh;
1104
1105    bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1106    inode = NULL;
1107    if (!bh)
1108        return ERR_PTR(-ENOENT);
1109    ino = le32_to_cpu(de->inode);
1110    brelse(bh);
1111
1112    if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1113        ext4_error(child->d_inode->i_sb, "ext4_get_parent",
1114               "bad inode number: %u", ino);
1115        return ERR_PTR(-EIO);
1116    }
1117
1118    return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1119}
1120
1121#define S_SHIFT 12
1122static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1123    [S_IFREG >> S_SHIFT] = EXT4_FT_REG_FILE,
1124    [S_IFDIR >> S_SHIFT] = EXT4_FT_DIR,
1125    [S_IFCHR >> S_SHIFT] = EXT4_FT_CHRDEV,
1126    [S_IFBLK >> S_SHIFT] = EXT4_FT_BLKDEV,
1127    [S_IFIFO >> S_SHIFT] = EXT4_FT_FIFO,
1128    [S_IFSOCK >> S_SHIFT] = EXT4_FT_SOCK,
1129    [S_IFLNK >> S_SHIFT] = EXT4_FT_SYMLINK,
1130};
1131
1132static inline void ext4_set_de_type(struct super_block *sb,
1133                struct ext4_dir_entry_2 *de,
1134                umode_t mode) {
1135    if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1136        de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1137}
1138
1139/*
1140 * Move count entries from end of map between two memory locations.
1141 * Returns pointer to last entry moved.
1142 */
1143static struct ext4_dir_entry_2 *
1144dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1145        unsigned blocksize)
1146{
1147    unsigned rec_len = 0;
1148
1149    while (count--) {
1150        struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1151                        (from + (map->offs<<2));
1152        rec_len = EXT4_DIR_REC_LEN(de->name_len);
1153        memcpy (to, de, rec_len);
1154        ((struct ext4_dir_entry_2 *) to)->rec_len =
1155                ext4_rec_len_to_disk(rec_len, blocksize);
1156        de->inode = 0;
1157        map++;
1158        to += rec_len;
1159    }
1160    return (struct ext4_dir_entry_2 *) (to - rec_len);
1161}
1162
1163/*
1164 * Compact each dir entry in the range to the minimal rec_len.
1165 * Returns pointer to last entry in range.
1166 */
1167static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1168{
1169    struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1170    unsigned rec_len = 0;
1171
1172    prev = to = de;
1173    while ((char*)de < base + blocksize) {
1174        next = ext4_next_entry(de, blocksize);
1175        if (de->inode && de->name_len) {
1176            rec_len = EXT4_DIR_REC_LEN(de->name_len);
1177            if (de > to)
1178                memmove(to, de, rec_len);
1179            to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1180            prev = to;
1181            to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1182        }
1183        de = next;
1184    }
1185    return prev;
1186}
1187
1188/*
1189 * Split a full leaf block to make room for a new dir entry.
1190 * Allocate a new block, and move entries so that they are approx. equally full.
1191 * Returns pointer to de in block into which the new entry will be inserted.
1192 */
1193static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1194            struct buffer_head **bh,struct dx_frame *frame,
1195            struct dx_hash_info *hinfo, int *error)
1196{
1197    unsigned blocksize = dir->i_sb->s_blocksize;
1198    unsigned count, continued;
1199    struct buffer_head *bh2;
1200    ext4_lblk_t newblock;
1201    u32 hash2;
1202    struct dx_map_entry *map;
1203    char *data1 = (*bh)->b_data, *data2;
1204    unsigned split, move, size;
1205    struct ext4_dir_entry_2 *de = NULL, *de2;
1206    int err = 0, i;
1207
1208    bh2 = ext4_append (handle, dir, &newblock, &err);
1209    if (!(bh2)) {
1210        brelse(*bh);
1211        *bh = NULL;
1212        goto errout;
1213    }
1214
1215    BUFFER_TRACE(*bh, "get_write_access");
1216    err = ext4_journal_get_write_access(handle, *bh);
1217    if (err)
1218        goto journal_error;
1219
1220    BUFFER_TRACE(frame->bh, "get_write_access");
1221    err = ext4_journal_get_write_access(handle, frame->bh);
1222    if (err)
1223        goto journal_error;
1224
1225    data2 = bh2->b_data;
1226
1227    /* create map in the end of data2 block */
1228    map = (struct dx_map_entry *) (data2 + blocksize);
1229    count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1230                 blocksize, hinfo, map);
1231    map -= count;
1232    dx_sort_map(map, count);
1233    /* Split the existing block in the middle, size-wise */
1234    size = 0;
1235    move = 0;
1236    for (i = count-1; i >= 0; i--) {
1237        /* is more than half of this entry in 2nd half of the block? */
1238        if (size + map[i].size/2 > blocksize/2)
1239            break;
1240        size += map[i].size;
1241        move++;
1242    }
1243    /* map index at which we will split */
1244    split = count - move;
1245    hash2 = map[split].hash;
1246    continued = hash2 == map[split - 1].hash;
1247    dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1248            (unsigned long)dx_get_block(frame->at),
1249                    hash2, split, count-split));
1250
1251    /* Fancy dance to stay within two buffers */
1252    de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1253    de = dx_pack_dirents(data1, blocksize);
1254    de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1255                       blocksize);
1256    de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
1257                        blocksize);
1258    dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1259    dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1260
1261    /* Which block gets the new entry? */
1262    if (hinfo->hash >= hash2)
1263    {
1264        swap(*bh, bh2);
1265        de = de2;
1266    }
1267    dx_insert_block(frame, hash2 + continued, newblock);
1268    err = ext4_handle_dirty_metadata(handle, dir, bh2);
1269    if (err)
1270        goto journal_error;
1271    err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
1272    if (err)
1273        goto journal_error;
1274    brelse(bh2);
1275    dxtrace(dx_show_index("frame", frame->entries));
1276    return de;
1277
1278journal_error:
1279    brelse(*bh);
1280    brelse(bh2);
1281    *bh = NULL;
1282    ext4_std_error(dir->i_sb, err);
1283errout:
1284    *error = err;
1285    return NULL;
1286}
1287
1288/*
1289 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1290 * it points to a directory entry which is guaranteed to be large
1291 * enough for new directory entry. If de is NULL, then
1292 * add_dirent_to_buf will attempt search the directory block for
1293 * space. It will return -ENOSPC if no space is available, and -EIO
1294 * and -EEXIST if directory entry already exists.
1295 *
1296 * NOTE! bh is NOT released in the case where ENOSPC is returned. In
1297 * all other cases bh is released.
1298 */
1299static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1300                 struct inode *inode, struct ext4_dir_entry_2 *de,
1301                 struct buffer_head *bh)
1302{
1303    struct inode *dir = dentry->d_parent->d_inode;
1304    const char *name = dentry->d_name.name;
1305    int namelen = dentry->d_name.len;
1306    unsigned int offset = 0;
1307    unsigned int blocksize = dir->i_sb->s_blocksize;
1308    unsigned short reclen;
1309    int nlen, rlen, err;
1310    char *top;
1311
1312    reclen = EXT4_DIR_REC_LEN(namelen);
1313    if (!de) {
1314        de = (struct ext4_dir_entry_2 *)bh->b_data;
1315        top = bh->b_data + blocksize - reclen;
1316        while ((char *) de <= top) {
1317            if (!ext4_check_dir_entry("ext4_add_entry", dir, de,
1318                          bh, offset)) {
1319                brelse(bh);
1320                return -EIO;
1321            }
1322            if (ext4_match(namelen, name, de)) {
1323                brelse(bh);
1324                return -EEXIST;
1325            }
1326            nlen = EXT4_DIR_REC_LEN(de->name_len);
1327            rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1328            if ((de->inode? rlen - nlen: rlen) >= reclen)
1329                break;
1330            de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1331            offset += rlen;
1332        }
1333        if ((char *) de > top)
1334            return -ENOSPC;
1335    }
1336    BUFFER_TRACE(bh, "get_write_access");
1337    err = ext4_journal_get_write_access(handle, bh);
1338    if (err) {
1339        ext4_std_error(dir->i_sb, err);
1340        brelse(bh);
1341        return err;
1342    }
1343
1344    /* By now the buffer is marked for journaling */
1345    nlen = EXT4_DIR_REC_LEN(de->name_len);
1346    rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1347    if (de->inode) {
1348        struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1349        de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1350        de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1351        de = de1;
1352    }
1353    de->file_type = EXT4_FT_UNKNOWN;
1354    if (inode) {
1355        de->inode = cpu_to_le32(inode->i_ino);
1356        ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1357    } else
1358        de->inode = 0;
1359    de->name_len = namelen;
1360    memcpy(de->name, name, namelen);
1361    /*
1362     * XXX shouldn't update any times until successful
1363     * completion of syscall, but too many callers depend
1364     * on this.
1365     *
1366     * XXX similarly, too many callers depend on
1367     * ext4_new_inode() setting the times, but error
1368     * recovery deletes the inode, so the worst that can
1369     * happen is that the times are slightly out of date
1370     * and/or different from the directory change time.
1371     */
1372    dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1373    ext4_update_dx_flag(dir);
1374    dir->i_version++;
1375    ext4_mark_inode_dirty(handle, dir);
1376    BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1377    err = ext4_handle_dirty_metadata(handle, dir, bh);
1378    if (err)
1379        ext4_std_error(dir->i_sb, err);
1380    brelse(bh);
1381    return 0;
1382}
1383
1384/*
1385 * This converts a one block unindexed directory to a 3 block indexed
1386 * directory, and adds the dentry to the indexed directory.
1387 */
1388static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1389                struct inode *inode, struct buffer_head *bh)
1390{
1391    struct inode *dir = dentry->d_parent->d_inode;
1392    const char *name = dentry->d_name.name;
1393    int namelen = dentry->d_name.len;
1394    struct buffer_head *bh2;
1395    struct dx_root *root;
1396    struct dx_frame frames[2], *frame;
1397    struct dx_entry *entries;
1398    struct ext4_dir_entry_2 *de, *de2;
1399    char *data1, *top;
1400    unsigned len;
1401    int retval;
1402    unsigned blocksize;
1403    struct dx_hash_info hinfo;
1404    ext4_lblk_t block;
1405    struct fake_dirent *fde;
1406
1407    blocksize = dir->i_sb->s_blocksize;
1408    dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1409    retval = ext4_journal_get_write_access(handle, bh);
1410    if (retval) {
1411        ext4_std_error(dir->i_sb, retval);
1412        brelse(bh);
1413        return retval;
1414    }
1415    root = (struct dx_root *) bh->b_data;
1416
1417    /* The 0th block becomes the root, move the dirents out */
1418    fde = &root->dotdot;
1419    de = (struct ext4_dir_entry_2 *)((char *)fde +
1420        ext4_rec_len_from_disk(fde->rec_len, blocksize));
1421    if ((char *) de >= (((char *) root) + blocksize)) {
1422        ext4_error(dir->i_sb, __func__,
1423               "invalid rec_len for '..' in inode %lu",
1424               dir->i_ino);
1425        brelse(bh);
1426        return -EIO;
1427    }
1428    len = ((char *) root) + blocksize - (char *) de;
1429
1430    /* Allocate new block for the 0th block's dirents */
1431    bh2 = ext4_append(handle, dir, &block, &retval);
1432    if (!(bh2)) {
1433        brelse(bh);
1434        return retval;
1435    }
1436    EXT4_I(dir)->i_flags |= EXT4_INDEX_FL;
1437    data1 = bh2->b_data;
1438
1439    memcpy (data1, de, len);
1440    de = (struct ext4_dir_entry_2 *) data1;
1441    top = data1 + len;
1442    while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1443        de = de2;
1444    de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1445                       blocksize);
1446    /* Initialize the root; the dot dirents already exist */
1447    de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1448    de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1449                       blocksize);
1450    memset (&root->info, 0, sizeof(root->info));
1451    root->info.info_length = sizeof(root->info);
1452    root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1453    entries = root->entries;
1454    dx_set_block(entries, 1);
1455    dx_set_count(entries, 1);
1456    dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1457
1458    /* Initialize as for dx_probe */
1459    hinfo.hash_version = root->info.hash_version;
1460    if (hinfo.hash_version <= DX_HASH_TEA)
1461        hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1462    hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1463    ext4fs_dirhash(name, namelen, &hinfo);
1464    frame = frames;
1465    frame->entries = entries;
1466    frame->at = entries;
1467    frame->bh = bh;
1468    bh = bh2;
1469    de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1470    dx_release (frames);
1471    if (!(de))
1472        return retval;
1473
1474    return add_dirent_to_buf(handle, dentry, inode, de, bh);
1475}
1476
1477/*
1478 * ext4_add_entry()
1479 *
1480 * adds a file entry to the specified directory, using the same
1481 * semantics as ext4_find_entry(). It returns NULL if it failed.
1482 *
1483 * NOTE!! The inode part of 'de' is left at 0 - which means you
1484 * may not sleep between calling this and putting something into
1485 * the entry, as someone else might have used it while you slept.
1486 */
1487static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1488              struct inode *inode)
1489{
1490    struct inode *dir = dentry->d_parent->d_inode;
1491    struct buffer_head *bh;
1492    struct ext4_dir_entry_2 *de;
1493    struct super_block *sb;
1494    int retval;
1495    int dx_fallback=0;
1496    unsigned blocksize;
1497    ext4_lblk_t block, blocks;
1498
1499    sb = dir->i_sb;
1500    blocksize = sb->s_blocksize;
1501    if (!dentry->d_name.len)
1502        return -EINVAL;
1503    if (is_dx(dir)) {
1504        retval = ext4_dx_add_entry(handle, dentry, inode);
1505        if (!retval || (retval != ERR_BAD_DX_DIR))
1506            return retval;
1507        EXT4_I(dir)->i_flags &= ~EXT4_INDEX_FL;
1508        dx_fallback++;
1509        ext4_mark_inode_dirty(handle, dir);
1510    }
1511    blocks = dir->i_size >> sb->s_blocksize_bits;
1512    for (block = 0; block < blocks; block++) {
1513        bh = ext4_bread(handle, dir, block, 0, &retval);
1514        if(!bh)
1515            return retval;
1516        retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1517        if (retval != -ENOSPC)
1518            return retval;
1519
1520        if (blocks == 1 && !dx_fallback &&
1521            EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1522            return make_indexed_dir(handle, dentry, inode, bh);
1523        brelse(bh);
1524    }
1525    bh = ext4_append(handle, dir, &block, &retval);
1526    if (!bh)
1527        return retval;
1528    de = (struct ext4_dir_entry_2 *) bh->b_data;
1529    de->inode = 0;
1530    de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
1531    return add_dirent_to_buf(handle, dentry, inode, de, bh);
1532}
1533
1534/*
1535 * Returns 0 for success, or a negative error value
1536 */
1537static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1538                 struct inode *inode)
1539{
1540    struct dx_frame frames[2], *frame;
1541    struct dx_entry *entries, *at;
1542    struct dx_hash_info hinfo;
1543    struct buffer_head *bh;
1544    struct inode *dir = dentry->d_parent->d_inode;
1545    struct super_block *sb = dir->i_sb;
1546    struct ext4_dir_entry_2 *de;
1547    int err;
1548
1549    frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1550    if (!frame)
1551        return err;
1552    entries = frame->entries;
1553    at = frame->at;
1554
1555    if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1556        goto cleanup;
1557
1558    BUFFER_TRACE(bh, "get_write_access");
1559    err = ext4_journal_get_write_access(handle, bh);
1560    if (err)
1561        goto journal_error;
1562
1563    err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1564    if (err != -ENOSPC) {
1565        bh = NULL;
1566        goto cleanup;
1567    }
1568
1569    /* Block full, should compress but for now just split */
1570    dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1571               dx_get_count(entries), dx_get_limit(entries)));
1572    /* Need to split index? */
1573    if (dx_get_count(entries) == dx_get_limit(entries)) {
1574        ext4_lblk_t newblock;
1575        unsigned icount = dx_get_count(entries);
1576        int levels = frame - frames;
1577        struct dx_entry *entries2;
1578        struct dx_node *node2;
1579        struct buffer_head *bh2;
1580
1581        if (levels && (dx_get_count(frames->entries) ==
1582                   dx_get_limit(frames->entries))) {
1583            ext4_warning(sb, __func__,
1584                     "Directory index full!");
1585            err = -ENOSPC;
1586            goto cleanup;
1587        }
1588        bh2 = ext4_append (handle, dir, &newblock, &err);
1589        if (!(bh2))
1590            goto cleanup;
1591        node2 = (struct dx_node *)(bh2->b_data);
1592        entries2 = node2->entries;
1593        node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1594                               sb->s_blocksize);
1595        node2->fake.inode = 0;
1596        BUFFER_TRACE(frame->bh, "get_write_access");
1597        err = ext4_journal_get_write_access(handle, frame->bh);
1598        if (err)
1599            goto journal_error;
1600        if (levels) {
1601            unsigned icount1 = icount/2, icount2 = icount - icount1;
1602            unsigned hash2 = dx_get_hash(entries + icount1);
1603            dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1604                       icount1, icount2));
1605
1606            BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1607            err = ext4_journal_get_write_access(handle,
1608                                 frames[0].bh);
1609            if (err)
1610                goto journal_error;
1611
1612            memcpy((char *) entries2, (char *) (entries + icount1),
1613                   icount2 * sizeof(struct dx_entry));
1614            dx_set_count(entries, icount1);
1615            dx_set_count(entries2, icount2);
1616            dx_set_limit(entries2, dx_node_limit(dir));
1617
1618            /* Which index block gets the new entry? */
1619            if (at - entries >= icount1) {
1620                frame->at = at = at - entries - icount1 + entries2;
1621                frame->entries = entries = entries2;
1622                swap(frame->bh, bh2);
1623            }
1624            dx_insert_block(frames + 0, hash2, newblock);
1625            dxtrace(dx_show_index("node", frames[1].entries));
1626            dxtrace(dx_show_index("node",
1627                   ((struct dx_node *) bh2->b_data)->entries));
1628            err = ext4_handle_dirty_metadata(handle, inode, bh2);
1629            if (err)
1630                goto journal_error;
1631            brelse (bh2);
1632        } else {
1633            dxtrace(printk(KERN_DEBUG
1634                       "Creating second level index...\n"));
1635            memcpy((char *) entries2, (char *) entries,
1636                   icount * sizeof(struct dx_entry));
1637            dx_set_limit(entries2, dx_node_limit(dir));
1638
1639            /* Set up root */
1640            dx_set_count(entries, 1);
1641            dx_set_block(entries + 0, newblock);
1642            ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1643
1644            /* Add new access path frame */
1645            frame = frames + 1;
1646            frame->at = at = at - entries + entries2;
1647            frame->entries = entries = entries2;
1648            frame->bh = bh2;
1649            err = ext4_journal_get_write_access(handle,
1650                                 frame->bh);
1651            if (err)
1652                goto journal_error;
1653        }
1654        ext4_handle_dirty_metadata(handle, inode, frames[0].bh);
1655    }
1656    de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1657    if (!de)
1658        goto cleanup;
1659    err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1660    bh = NULL;
1661    goto cleanup;
1662
1663journal_error:
1664    ext4_std_error(dir->i_sb, err);
1665cleanup:
1666    if (bh)
1667        brelse(bh);
1668    dx_release(frames);
1669    return err;
1670}
1671
1672/*
1673 * ext4_delete_entry deletes a directory entry by merging it with the
1674 * previous entry
1675 */
1676static int ext4_delete_entry(handle_t *handle,
1677                 struct inode *dir,
1678                 struct ext4_dir_entry_2 *de_del,
1679                 struct buffer_head *bh)
1680{
1681    struct ext4_dir_entry_2 *de, *pde;
1682    unsigned int blocksize = dir->i_sb->s_blocksize;
1683    int i;
1684
1685    i = 0;
1686    pde = NULL;
1687    de = (struct ext4_dir_entry_2 *) bh->b_data;
1688    while (i < bh->b_size) {
1689        if (!ext4_check_dir_entry("ext4_delete_entry", dir, de, bh, i))
1690            return -EIO;
1691        if (de == de_del) {
1692            BUFFER_TRACE(bh, "get_write_access");
1693            ext4_journal_get_write_access(handle, bh);
1694            if (pde)
1695                pde->rec_len = ext4_rec_len_to_disk(
1696                    ext4_rec_len_from_disk(pde->rec_len,
1697                                   blocksize) +
1698                    ext4_rec_len_from_disk(de->rec_len,
1699                                   blocksize),
1700                    blocksize);
1701            else
1702                de->inode = 0;
1703            dir->i_version++;
1704            BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1705            ext4_handle_dirty_metadata(handle, dir, bh);
1706            return 0;
1707        }
1708        i += ext4_rec_len_from_disk(de->rec_len, blocksize);
1709        pde = de;
1710        de = ext4_next_entry(de, blocksize);
1711    }
1712    return -ENOENT;
1713}
1714
1715/*
1716 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
1717 * since this indicates that nlinks count was previously 1.
1718 */
1719static void ext4_inc_count(handle_t *handle, struct inode *inode)
1720{
1721    inc_nlink(inode);
1722    if (is_dx(inode) && inode->i_nlink > 1) {
1723        /* limit is 16-bit i_links_count */
1724        if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
1725            inode->i_nlink = 1;
1726            EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
1727                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
1728        }
1729    }
1730}
1731
1732/*
1733 * If a directory had nlink == 1, then we should let it be 1. This indicates
1734 * directory has >EXT4_LINK_MAX subdirs.
1735 */
1736static void ext4_dec_count(handle_t *handle, struct inode *inode)
1737{
1738    drop_nlink(inode);
1739    if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1740        inc_nlink(inode);
1741}
1742
1743
1744static int ext4_add_nondir(handle_t *handle,
1745        struct dentry *dentry, struct inode *inode)
1746{
1747    int err = ext4_add_entry(handle, dentry, inode);
1748    if (!err) {
1749        ext4_mark_inode_dirty(handle, inode);
1750        d_instantiate(dentry, inode);
1751        unlock_new_inode(inode);
1752        return 0;
1753    }
1754    drop_nlink(inode);
1755    unlock_new_inode(inode);
1756    iput(inode);
1757    return err;
1758}
1759
1760/*
1761 * By the time this is called, we already have created
1762 * the directory cache entry for the new file, but it
1763 * is so far negative - it has no inode.
1764 *
1765 * If the create succeeds, we fill in the inode information
1766 * with d_instantiate().
1767 */
1768static int ext4_create(struct inode *dir, struct dentry *dentry, int mode,
1769               struct nameidata *nd)
1770{
1771    handle_t *handle;
1772    struct inode *inode;
1773    int err, retries = 0;
1774
1775retry:
1776    handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1777                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1778                    2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1779    if (IS_ERR(handle))
1780        return PTR_ERR(handle);
1781
1782    if (IS_DIRSYNC(dir))
1783        ext4_handle_sync(handle);
1784
1785    inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1786    err = PTR_ERR(inode);
1787    if (!IS_ERR(inode)) {
1788        inode->i_op = &ext4_file_inode_operations;
1789        inode->i_fop = &ext4_file_operations;
1790        ext4_set_aops(inode);
1791        err = ext4_add_nondir(handle, dentry, inode);
1792    }
1793    ext4_journal_stop(handle);
1794    if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1795        goto retry;
1796    return err;
1797}
1798
1799static int ext4_mknod(struct inode *dir, struct dentry *dentry,
1800              int mode, dev_t rdev)
1801{
1802    handle_t *handle;
1803    struct inode *inode;
1804    int err, retries = 0;
1805
1806    if (!new_valid_dev(rdev))
1807        return -EINVAL;
1808
1809retry:
1810    handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1811                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1812                    2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1813    if (IS_ERR(handle))
1814        return PTR_ERR(handle);
1815
1816    if (IS_DIRSYNC(dir))
1817        ext4_handle_sync(handle);
1818
1819    inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1820    err = PTR_ERR(inode);
1821    if (!IS_ERR(inode)) {
1822        init_special_inode(inode, inode->i_mode, rdev);
1823#ifdef CONFIG_EXT4_FS_XATTR
1824        inode->i_op = &ext4_special_inode_operations;
1825#endif
1826        err = ext4_add_nondir(handle, dentry, inode);
1827    }
1828    ext4_journal_stop(handle);
1829    if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1830        goto retry;
1831    return err;
1832}
1833
1834static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1835{
1836    handle_t *handle;
1837    struct inode *inode;
1838    struct buffer_head *dir_block;
1839    struct ext4_dir_entry_2 *de;
1840    unsigned int blocksize = dir->i_sb->s_blocksize;
1841    int err, retries = 0;
1842
1843    if (EXT4_DIR_LINK_MAX(dir))
1844        return -EMLINK;
1845
1846retry:
1847    handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1848                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1849                    2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1850    if (IS_ERR(handle))
1851        return PTR_ERR(handle);
1852
1853    if (IS_DIRSYNC(dir))
1854        ext4_handle_sync(handle);
1855
1856    inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
1857                   &dentry->d_name, 0);
1858    err = PTR_ERR(inode);
1859    if (IS_ERR(inode))
1860        goto out_stop;
1861
1862    inode->i_op = &ext4_dir_inode_operations;
1863    inode->i_fop = &ext4_dir_operations;
1864    inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1865    dir_block = ext4_bread(handle, inode, 0, 1, &err);
1866    if (!dir_block)
1867        goto out_clear_inode;
1868    BUFFER_TRACE(dir_block, "get_write_access");
1869    ext4_journal_get_write_access(handle, dir_block);
1870    de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1871    de->inode = cpu_to_le32(inode->i_ino);
1872    de->name_len = 1;
1873    de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
1874                       blocksize);
1875    strcpy(de->name, ".");
1876    ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1877    de = ext4_next_entry(de, blocksize);
1878    de->inode = cpu_to_le32(dir->i_ino);
1879    de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
1880                       blocksize);
1881    de->name_len = 2;
1882    strcpy(de->name, "..");
1883    ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1884    inode->i_nlink = 2;
1885    BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
1886    ext4_handle_dirty_metadata(handle, dir, dir_block);
1887    brelse(dir_block);
1888    ext4_mark_inode_dirty(handle, inode);
1889    err = ext4_add_entry(handle, dentry, inode);
1890    if (err) {
1891out_clear_inode:
1892        clear_nlink(inode);
1893        unlock_new_inode(inode);
1894        ext4_mark_inode_dirty(handle, inode);
1895        iput(inode);
1896        goto out_stop;
1897    }
1898    ext4_inc_count(handle, dir);
1899    ext4_update_dx_flag(dir);
1900    ext4_mark_inode_dirty(handle, dir);
1901    d_instantiate(dentry, inode);
1902    unlock_new_inode(inode);
1903out_stop:
1904    ext4_journal_stop(handle);
1905    if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1906        goto retry;
1907    return err;
1908}
1909
1910/*
1911 * routine to check that the specified directory is empty (for rmdir)
1912 */
1913static int empty_dir(struct inode *inode)
1914{
1915    unsigned int offset;
1916    struct buffer_head *bh;
1917    struct ext4_dir_entry_2 *de, *de1;
1918    struct super_block *sb;
1919    int err = 0;
1920
1921    sb = inode->i_sb;
1922    if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1923        !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
1924        if (err)
1925            ext4_error(inode->i_sb, __func__,
1926                   "error %d reading directory #%lu offset 0",
1927                   err, inode->i_ino);
1928        else
1929            ext4_warning(inode->i_sb, __func__,
1930                     "bad directory (dir #%lu) - no data block",
1931                     inode->i_ino);
1932        return 1;
1933    }
1934    de = (struct ext4_dir_entry_2 *) bh->b_data;
1935    de1 = ext4_next_entry(de, sb->s_blocksize);
1936    if (le32_to_cpu(de->inode) != inode->i_ino ||
1937            !le32_to_cpu(de1->inode) ||
1938            strcmp(".", de->name) ||
1939            strcmp("..", de1->name)) {
1940        ext4_warning(inode->i_sb, "empty_dir",
1941                 "bad directory (dir #%lu) - no `.' or `..'",
1942                 inode->i_ino);
1943        brelse(bh);
1944        return 1;
1945    }
1946    offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
1947         ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
1948    de = ext4_next_entry(de1, sb->s_blocksize);
1949    while (offset < inode->i_size) {
1950        if (!bh ||
1951            (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1952            err = 0;
1953            brelse(bh);
1954            bh = ext4_bread(NULL, inode,
1955                offset >> EXT4_BLOCK_SIZE_BITS(sb), 0, &err);
1956            if (!bh) {
1957                if (err)
1958                    ext4_error(sb, __func__,
1959                           "error %d reading directory"
1960                           " #%lu offset %u",
1961                           err, inode->i_ino, offset);
1962                offset += sb->s_blocksize;
1963                continue;
1964            }
1965            de = (struct ext4_dir_entry_2 *) bh->b_data;
1966        }
1967        if (!ext4_check_dir_entry("empty_dir", inode, de, bh, offset)) {
1968            de = (struct ext4_dir_entry_2 *)(bh->b_data +
1969                             sb->s_blocksize);
1970            offset = (offset | (sb->s_blocksize - 1)) + 1;
1971            continue;
1972        }
1973        if (le32_to_cpu(de->inode)) {
1974            brelse(bh);
1975            return 0;
1976        }
1977        offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
1978        de = ext4_next_entry(de, sb->s_blocksize);
1979    }
1980    brelse(bh);
1981    return 1;
1982}
1983
1984/* ext4_orphan_add() links an unlinked or truncated inode into a list of
1985 * such inodes, starting at the superblock, in case we crash before the
1986 * file is closed/deleted, or in case the inode truncate spans multiple
1987 * transactions and the last transaction is not recovered after a crash.
1988 *
1989 * At filesystem recovery time, we walk this list deleting unlinked
1990 * inodes and truncating linked inodes in ext4_orphan_cleanup().
1991 */
1992int ext4_orphan_add(handle_t *handle, struct inode *inode)
1993{
1994    struct super_block *sb = inode->i_sb;
1995    struct ext4_iloc iloc;
1996    int err = 0, rc;
1997
1998    if (!ext4_handle_valid(handle))
1999        return 0;
2000
2001    mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
2002    if (!list_empty(&EXT4_I(inode)->i_orphan))
2003        goto out_unlock;
2004
2005    /* Orphan handling is only valid for files with data blocks
2006     * being truncated, or files being unlinked. */
2007
2008    /* @@@ FIXME: Observation from aviro:
2009     * I think I can trigger J_ASSERT in ext4_orphan_add(). We block
2010     * here (on s_orphan_lock), so race with ext4_link() which might bump
2011     * ->i_nlink. For, say it, character device. Not a regular file,
2012     * not a directory, not a symlink and ->i_nlink > 0.
2013     *
2014     * tytso, 4/25/2009: I'm not sure how that could happen;
2015     * shouldn't the fs core protect us from these sort of
2016     * unlink()/link() races?
2017     */
2018    J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2019          S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2020
2021    BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2022    err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2023    if (err)
2024        goto out_unlock;
2025
2026    err = ext4_reserve_inode_write(handle, inode, &iloc);
2027    if (err)
2028        goto out_unlock;
2029
2030    /* Insert this inode at the head of the on-disk orphan list... */
2031    NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2032    EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2033    err = ext4_handle_dirty_metadata(handle, inode, EXT4_SB(sb)->s_sbh);
2034    rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2035    if (!err)
2036        err = rc;
2037
2038    /* Only add to the head of the in-memory list if all the
2039     * previous operations succeeded. If the orphan_add is going to
2040     * fail (possibly taking the journal offline), we can't risk
2041     * leaving the inode on the orphan list: stray orphan-list
2042     * entries can cause panics at unmount time.
2043     *
2044     * This is safe: on error we're going to ignore the orphan list
2045     * anyway on the next recovery. */
2046    if (!err)
2047        list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2048
2049    jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2050    jbd_debug(4, "orphan inode %lu will point to %d\n",
2051            inode->i_ino, NEXT_ORPHAN(inode));
2052out_unlock:
2053    mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2054    ext4_std_error(inode->i_sb, err);
2055    return err;
2056}
2057
2058/*
2059 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2060 * of such inodes stored on disk, because it is finally being cleaned up.
2061 */
2062int ext4_orphan_del(handle_t *handle, struct inode *inode)
2063{
2064    struct list_head *prev;
2065    struct ext4_inode_info *ei = EXT4_I(inode);
2066    struct ext4_sb_info *sbi;
2067    __u32 ino_next;
2068    struct ext4_iloc iloc;
2069    int err = 0;
2070
2071    if (!ext4_handle_valid(handle))
2072        return 0;
2073
2074    mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2075    if (list_empty(&ei->i_orphan))
2076        goto out;
2077
2078    ino_next = NEXT_ORPHAN(inode);
2079    prev = ei->i_orphan.prev;
2080    sbi = EXT4_SB(inode->i_sb);
2081
2082    jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2083
2084    list_del_init(&ei->i_orphan);
2085
2086    /* If we're on an error path, we may not have a valid
2087     * transaction handle with which to update the orphan list on
2088     * disk, but we still need to remove the inode from the linked
2089     * list in memory. */
2090    if (sbi->s_journal && !handle)
2091        goto out;
2092
2093    err = ext4_reserve_inode_write(handle, inode, &iloc);
2094    if (err)
2095        goto out_err;
2096
2097    if (prev == &sbi->s_orphan) {
2098        jbd_debug(4, "superblock will point to %u\n", ino_next);
2099        BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2100        err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2101        if (err)
2102            goto out_brelse;
2103        sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2104        err = ext4_handle_dirty_metadata(handle, inode, sbi->s_sbh);
2105    } else {
2106        struct ext4_iloc iloc2;
2107        struct inode *i_prev =
2108            &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2109
2110        jbd_debug(4, "orphan inode %lu will point to %u\n",
2111              i_prev->i_ino, ino_next);
2112        err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2113        if (err)
2114            goto out_brelse;
2115        NEXT_ORPHAN(i_prev) = ino_next;
2116        err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2117    }
2118    if (err)
2119        goto out_brelse;
2120    NEXT_ORPHAN(inode) = 0;
2121    err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2122
2123out_err:
2124    ext4_std_error(inode->i_sb, err);
2125out:
2126    mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2127    return err;
2128
2129out_brelse:
2130    brelse(iloc.bh);
2131    goto out_err;
2132}
2133
2134static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2135{
2136    int retval;
2137    struct inode *inode;
2138    struct buffer_head *bh;
2139    struct ext4_dir_entry_2 *de;
2140    handle_t *handle;
2141
2142    /* Initialize quotas before so that eventual writes go in
2143     * separate transaction */
2144    vfs_dq_init(dentry->d_inode);
2145    handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2146    if (IS_ERR(handle))
2147        return PTR_ERR(handle);
2148
2149    retval = -ENOENT;
2150    bh = ext4_find_entry(dir, &dentry->d_name, &de);
2151    if (!bh)
2152        goto end_rmdir;
2153
2154    if (IS_DIRSYNC(dir))
2155        ext4_handle_sync(handle);
2156
2157    inode = dentry->d_inode;
2158
2159    retval = -EIO;
2160    if (le32_to_cpu(de->inode) != inode->i_ino)
2161        goto end_rmdir;
2162
2163    retval = -ENOTEMPTY;
2164    if (!empty_dir(inode))
2165        goto end_rmdir;
2166
2167    retval = ext4_delete_entry(handle, dir, de, bh);
2168    if (retval)
2169        goto end_rmdir;
2170    if (!EXT4_DIR_LINK_EMPTY(inode))
2171        ext4_warning(inode->i_sb, "ext4_rmdir",
2172                 "empty directory has too many links (%d)",
2173                 inode->i_nlink);
2174    inode->i_version++;
2175    clear_nlink(inode);
2176    /* There's no need to set i_disksize: the fact that i_nlink is
2177     * zero will ensure that the right thing happens during any
2178     * recovery. */
2179    inode->i_size = 0;
2180    ext4_orphan_add(handle, inode);
2181    inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2182    ext4_mark_inode_dirty(handle, inode);
2183    ext4_dec_count(handle, dir);
2184    ext4_update_dx_flag(dir);
2185    ext4_mark_inode_dirty(handle, dir);
2186
2187end_rmdir:
2188    ext4_journal_stop(handle);
2189    brelse(bh);
2190    return retval;
2191}
2192
2193static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2194{
2195    int retval;
2196    struct inode *inode;
2197    struct buffer_head *bh;
2198    struct ext4_dir_entry_2 *de;
2199    handle_t *handle;
2200
2201    /* Initialize quotas before so that eventual writes go
2202     * in separate transaction */
2203    vfs_dq_init(dentry->d_inode);
2204    handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2205    if (IS_ERR(handle))
2206        return PTR_ERR(handle);
2207
2208    if (IS_DIRSYNC(dir))
2209        ext4_handle_sync(handle);
2210
2211    retval = -ENOENT;
2212    bh = ext4_find_entry(dir, &dentry->d_name, &de);
2213    if (!bh)
2214        goto end_unlink;
2215
2216    inode = dentry->d_inode;
2217
2218    retval = -EIO;
2219    if (le32_to_cpu(de->inode) != inode->i_ino)
2220        goto end_unlink;
2221
2222    if (!inode->i_nlink) {
2223        ext4_warning(inode->i_sb, "ext4_unlink",
2224                 "Deleting nonexistent file (%lu), %d",
2225                 inode->i_ino, inode->i_nlink);
2226        inode->i_nlink = 1;
2227    }
2228    retval = ext4_delete_entry(handle, dir, de, bh);
2229    if (retval)
2230        goto end_unlink;
2231    dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2232    ext4_update_dx_flag(dir);
2233    ext4_mark_inode_dirty(handle, dir);
2234    drop_nlink(inode);
2235    if (!inode->i_nlink)
2236        ext4_orphan_add(handle, inode);
2237    inode->i_ctime = ext4_current_time(inode);
2238    ext4_mark_inode_dirty(handle, inode);
2239    retval = 0;
2240
2241end_unlink:
2242    ext4_journal_stop(handle);
2243    brelse(bh);
2244    return retval;
2245}
2246
2247static int ext4_symlink(struct inode *dir,
2248            struct dentry *dentry, const char *symname)
2249{
2250    handle_t *handle;
2251    struct inode *inode;
2252    int l, err, retries = 0;
2253
2254    l = strlen(symname)+1;
2255    if (l > dir->i_sb->s_blocksize)
2256        return -ENAMETOOLONG;
2257
2258retry:
2259    handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2260                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 5 +
2261                    2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
2262    if (IS_ERR(handle))
2263        return PTR_ERR(handle);
2264
2265    if (IS_DIRSYNC(dir))
2266        ext4_handle_sync(handle);
2267
2268    inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2269                   &dentry->d_name, 0);
2270    err = PTR_ERR(inode);
2271    if (IS_ERR(inode))
2272        goto out_stop;
2273
2274    if (l > sizeof(EXT4_I(inode)->i_data)) {
2275        inode->i_op = &ext4_symlink_inode_operations;
2276        ext4_set_aops(inode);
2277        /*
2278         * page_symlink() calls into ext4_prepare/commit_write.
2279         * We have a transaction open. All is sweetness. It also sets
2280         * i_size in generic_commit_write().
2281         */
2282        err = __page_symlink(inode, symname, l, 1);
2283        if (err) {
2284            clear_nlink(inode);
2285            unlock_new_inode(inode);
2286            ext4_mark_inode_dirty(handle, inode);
2287            iput(inode);
2288            goto out_stop;
2289        }
2290    } else {
2291        /* clear the extent format for fast symlink */
2292        EXT4_I(inode)->i_flags &= ~EXT4_EXTENTS_FL;
2293        inode->i_op = &ext4_fast_symlink_inode_operations;
2294        memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2295        inode->i_size = l-1;
2296    }
2297    EXT4_I(inode)->i_disksize = inode->i_size;
2298    err = ext4_add_nondir(handle, dentry, inode);
2299out_stop:
2300    ext4_journal_stop(handle);
2301    if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2302        goto retry;
2303    return err;
2304}
2305
2306static int ext4_link(struct dentry *old_dentry,
2307             struct inode *dir, struct dentry *dentry)
2308{
2309    handle_t *handle;
2310    struct inode *inode = old_dentry->d_inode;
2311    int err, retries = 0;
2312
2313    if (EXT4_DIR_LINK_MAX(inode))
2314        return -EMLINK;
2315
2316    /*
2317     * Return -ENOENT if we've raced with unlink and i_nlink is 0. Doing
2318     * otherwise has the potential to corrupt the orphan inode list.
2319     */
2320    if (inode->i_nlink == 0)
2321        return -ENOENT;
2322
2323retry:
2324    handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2325                    EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2326    if (IS_ERR(handle))
2327        return PTR_ERR(handle);
2328
2329    if (IS_DIRSYNC(dir))
2330        ext4_handle_sync(handle);
2331
2332    inode->i_ctime = ext4_current_time(inode);
2333    ext4_inc_count(handle, inode);
2334    atomic_inc(&inode->i_count);
2335
2336    err = ext4_add_entry(handle, dentry, inode);
2337    if (!err) {
2338        ext4_mark_inode_dirty(handle, inode);
2339        d_instantiate(dentry, inode);
2340    } else {
2341        drop_nlink(inode);
2342        iput(inode);
2343    }
2344    ext4_journal_stop(handle);
2345    if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2346        goto retry;
2347    return err;
2348}
2349
2350#define PARENT_INO(buffer, size) \
2351    (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2352
2353/*
2354 * Anybody can rename anything with this: the permission checks are left to the
2355 * higher-level routines.
2356 */
2357static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2358               struct inode *new_dir, struct dentry *new_dentry)
2359{
2360    handle_t *handle;
2361    struct inode *old_inode, *new_inode;
2362    struct buffer_head *old_bh, *new_bh, *dir_bh;
2363    struct ext4_dir_entry_2 *old_de, *new_de;
2364    int retval, force_da_alloc = 0;
2365
2366    old_bh = new_bh = dir_bh = NULL;
2367
2368    /* Initialize quotas before so that eventual writes go
2369     * in separate transaction */
2370    if (new_dentry->d_inode)
2371        vfs_dq_init(new_dentry->d_inode);
2372    handle = ext4_journal_start(old_dir, 2 *
2373                    EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2374                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2375    if (IS_ERR(handle))
2376        return PTR_ERR(handle);
2377
2378    if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2379        ext4_handle_sync(handle);
2380
2381    old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2382    /*
2383     * Check for inode number is _not_ due to possible IO errors.
2384     * We might rmdir the source, keep it as pwd of some process
2385     * and merrily kill the link to whatever was created under the
2386     * same name. Goodbye sticky bit ;-<
2387     */
2388    old_inode = old_dentry->d_inode;
2389    retval = -ENOENT;
2390    if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2391        goto end_rename;
2392
2393    new_inode = new_dentry->d_inode;
2394    new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2395    if (new_bh) {
2396        if (!new_inode) {
2397            brelse(new_bh);
2398            new_bh = NULL;
2399        }
2400    }
2401    if (S_ISDIR(old_inode->i_mode)) {
2402        if (new_inode) {
2403            retval = -ENOTEMPTY;
2404            if (!empty_dir(new_inode))
2405                goto end_rename;
2406        }
2407        retval = -EIO;
2408        dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2409        if (!dir_bh)
2410            goto end_rename;
2411        if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2412                old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2413            goto end_rename;
2414        retval = -EMLINK;
2415        if (!new_inode && new_dir != old_dir &&
2416                new_dir->i_nlink >= EXT4_LINK_MAX)
2417            goto end_rename;
2418    }
2419    if (!new_bh) {
2420        retval = ext4_add_entry(handle, new_dentry, old_inode);
2421        if (retval)
2422            goto end_rename;
2423    } else {
2424        BUFFER_TRACE(new_bh, "get write access");
2425        ext4_journal_get_write_access(handle, new_bh);
2426        new_de->inode = cpu_to_le32(old_inode->i_ino);
2427        if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2428                          EXT4_FEATURE_INCOMPAT_FILETYPE))
2429            new_de->file_type = old_de->file_type;
2430        new_dir->i_version++;
2431        new_dir->i_ctime = new_dir->i_mtime =
2432                    ext4_current_time(new_dir);
2433        ext4_mark_inode_dirty(handle, new_dir);
2434        BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2435        ext4_handle_dirty_metadata(handle, new_dir, new_bh);
2436        brelse(new_bh);
2437        new_bh = NULL;
2438    }
2439
2440    /*
2441     * Like most other Unix systems, set the ctime for inodes on a
2442     * rename.
2443     */
2444    old_inode->i_ctime = ext4_current_time(old_inode);
2445    ext4_mark_inode_dirty(handle, old_inode);
2446
2447    /*
2448     * ok, that's it
2449     */
2450    if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2451        old_de->name_len != old_dentry->d_name.len ||
2452        strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2453        (retval = ext4_delete_entry(handle, old_dir,
2454                    old_de, old_bh)) == -ENOENT) {
2455        /* old_de could have moved from under us during htree split, so
2456         * make sure that we are deleting the right entry. We might
2457         * also be pointing to a stale entry in the unused part of
2458         * old_bh so just checking inum and the name isn't enough. */
2459        struct buffer_head *old_bh2;
2460        struct ext4_dir_entry_2 *old_de2;
2461
2462        old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2463        if (old_bh2) {
2464            retval = ext4_delete_entry(handle, old_dir,
2465                           old_de2, old_bh2);
2466            brelse(old_bh2);
2467        }
2468    }
2469    if (retval) {
2470        ext4_warning(old_dir->i_sb, "ext4_rename",
2471                "Deleting old file (%lu), %d, error=%d",
2472                old_dir->i_ino, old_dir->i_nlink, retval);
2473    }
2474
2475    if (new_inode) {
2476        ext4_dec_count(handle, new_inode);
2477        new_inode->i_ctime = ext4_current_time(new_inode);
2478    }
2479    old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2480    ext4_update_dx_flag(old_dir);
2481    if (dir_bh) {
2482        BUFFER_TRACE(dir_bh, "get_write_access");
2483        ext4_journal_get_write_access(handle, dir_bh);
2484        PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2485                        cpu_to_le32(new_dir->i_ino);
2486        BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2487        ext4_handle_dirty_metadata(handle, old_dir, dir_bh);
2488        ext4_dec_count(handle, old_dir);
2489        if (new_inode) {
2490            /* checked empty_dir above, can't have another parent,
2491             * ext4_dec_count() won't work for many-linked dirs */
2492            new_inode->i_nlink = 0;
2493        } else {
2494            ext4_inc_count(handle, new_dir);
2495            ext4_update_dx_flag(new_dir);
2496            ext4_mark_inode_dirty(handle, new_dir);
2497        }
2498    }
2499    ext4_mark_inode_dirty(handle, old_dir);
2500    if (new_inode) {
2501        ext4_mark_inode_dirty(handle, new_inode);
2502        if (!new_inode->i_nlink)
2503            ext4_orphan_add(handle, new_inode);
2504        if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2505            force_da_alloc = 1;
2506    }
2507    retval = 0;
2508
2509end_rename:
2510    brelse(dir_bh);
2511    brelse(old_bh);
2512    brelse(new_bh);
2513    ext4_journal_stop(handle);
2514    if (retval == 0 && force_da_alloc)
2515        ext4_alloc_da_blocks(old_inode);
2516    return retval;
2517}
2518
2519/*
2520 * directories can handle most operations...
2521 */
2522const struct inode_operations ext4_dir_inode_operations = {
2523    .create = ext4_create,
2524    .lookup = ext4_lookup,
2525    .link = ext4_link,
2526    .unlink = ext4_unlink,
2527    .symlink = ext4_symlink,
2528    .mkdir = ext4_mkdir,
2529    .rmdir = ext4_rmdir,
2530    .mknod = ext4_mknod,
2531    .rename = ext4_rename,
2532    .setattr = ext4_setattr,
2533#ifdef CONFIG_EXT4_FS_XATTR
2534    .setxattr = generic_setxattr,
2535    .getxattr = generic_getxattr,
2536    .listxattr = ext4_listxattr,
2537    .removexattr = generic_removexattr,
2538#endif
2539    .permission = ext4_permission,
2540    .fiemap = ext4_fiemap,
2541};
2542
2543const struct inode_operations ext4_special_inode_operations = {
2544    .setattr = ext4_setattr,
2545#ifdef CONFIG_EXT4_FS_XATTR
2546    .setxattr = generic_setxattr,
2547    .getxattr = generic_getxattr,
2548    .listxattr = ext4_listxattr,
2549    .removexattr = generic_removexattr,
2550#endif
2551    .permission = ext4_permission,
2552};
2553

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