--- /dev/null
+/*
+ * linux/fs/ext4/namei.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * from
+ *
+ * linux/fs/minix/namei.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * Big-endian to little-endian byte-swapping/bitmaps by
+ * David S. Miller (davem@caip.rutgers.edu), 1995
+ * Directory entry file type support and forward compatibility hooks
+ * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
+ * Hash Tree Directory indexing (c)
+ * Daniel Phillips, 2001
+ * Hash Tree Directory indexing porting
+ * Christopher Li, 2002
+ * Hash Tree Directory indexing cleanup
+ * Theodore Ts'o, 2002
+ */
+
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/jbd2.h>
+#include <linux/time.h>
+#include <linux/ext4_fs.h>
+#include <linux/ext4_jbd2.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+#include <linux/bio.h>
+#include <linux/smp_lock.h>
+#include <linux/vs_tag.h>
+
+#include "namei.h"
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * define how far ahead to read directories while searching them.
+ */
+#define NAMEI_RA_CHUNKS 2
+#define NAMEI_RA_BLOCKS 4
+#define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
+#define NAMEI_RA_INDEX(c,b) (((c) * NAMEI_RA_BLOCKS) + (b))
+
+static struct buffer_head *ext4_append(handle_t *handle,
+ struct inode *inode,
+ u32 *block, int *err)
+{
+ struct buffer_head *bh;
+
+ *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
+
+ if ((bh = ext4_bread(handle, inode, *block, 1, err))) {
+ inode->i_size += inode->i_sb->s_blocksize;
+ EXT4_I(inode)->i_disksize = inode->i_size;
+ ext4_journal_get_write_access(handle,bh);
+ }
+ return bh;
+}
+
+#ifndef assert
+#define assert(test) J_ASSERT(test)
+#endif
+
+#ifndef swap
+#define swap(x, y) do { typeof(x) z = x; x = y; y = z; } while (0)
+#endif
+
+#ifdef DX_DEBUG
+#define dxtrace(command) command
+#else
+#define dxtrace(command)
+#endif
+
+struct fake_dirent
+{
+ __le32 inode;
+ __le16 rec_len;
+ u8 name_len;
+ u8 file_type;
+};
+
+struct dx_countlimit
+{
+ __le16 limit;
+ __le16 count;
+};
+
+struct dx_entry
+{
+ __le32 hash;
+ __le32 block;
+};
+
+/*
+ * dx_root_info is laid out so that if it should somehow get overlaid by a
+ * dirent the two low bits of the hash version will be zero. Therefore, the
+ * hash version mod 4 should never be 0. Sincerely, the paranoia department.
+ */
+
+struct dx_root
+{
+ struct fake_dirent dot;
+ char dot_name[4];
+ struct fake_dirent dotdot;
+ char dotdot_name[4];
+ struct dx_root_info
+ {
+ __le32 reserved_zero;
+ u8 hash_version;
+ u8 info_length; /* 8 */
+ u8 indirect_levels;
+ u8 unused_flags;
+ }
+ info;
+ struct dx_entry entries[0];
+};
+
+struct dx_node
+{
+ struct fake_dirent fake;
+ struct dx_entry entries[0];
+};
+
+
+struct dx_frame
+{
+ struct buffer_head *bh;
+ struct dx_entry *entries;
+ struct dx_entry *at;
+};
+
+struct dx_map_entry
+{
+ u32 hash;
+ u32 offs;
+};
+
+#ifdef CONFIG_EXT4_INDEX
+static inline unsigned dx_get_block (struct dx_entry *entry);
+static void dx_set_block (struct dx_entry *entry, unsigned value);
+static inline unsigned dx_get_hash (struct dx_entry *entry);
+static void dx_set_hash (struct dx_entry *entry, unsigned value);
+static unsigned dx_get_count (struct dx_entry *entries);
+static unsigned dx_get_limit (struct dx_entry *entries);
+static void dx_set_count (struct dx_entry *entries, unsigned value);
+static void dx_set_limit (struct dx_entry *entries, unsigned value);
+static unsigned dx_root_limit (struct inode *dir, unsigned infosize);
+static unsigned dx_node_limit (struct inode *dir);
+static struct dx_frame *dx_probe(struct dentry *dentry,
+ struct inode *dir,
+ struct dx_hash_info *hinfo,
+ struct dx_frame *frame,
+ int *err);
+static void dx_release (struct dx_frame *frames);
+static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
+ struct dx_hash_info *hinfo, struct dx_map_entry map[]);
+static void dx_sort_map(struct dx_map_entry *map, unsigned count);
+static struct ext4_dir_entry_2 *dx_move_dirents (char *from, char *to,
+ struct dx_map_entry *offsets, int count);
+static struct ext4_dir_entry_2* dx_pack_dirents (char *base, int size);
+static void dx_insert_block (struct dx_frame *frame, u32 hash, u32 block);
+static int ext4_htree_next_block(struct inode *dir, __u32 hash,
+ struct dx_frame *frame,
+ struct dx_frame *frames,
+ __u32 *start_hash);
+static struct buffer_head * ext4_dx_find_entry(struct dentry *dentry,
+ struct ext4_dir_entry_2 **res_dir, int *err);
+static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
+ struct inode *inode);
+
+/*
+ * Future: use high four bits of block for coalesce-on-delete flags
+ * Mask them off for now.
+ */
+
+static inline unsigned dx_get_block (struct dx_entry *entry)
+{
+ return le32_to_cpu(entry->block) & 0x00ffffff;
+}
+
+static inline void dx_set_block (struct dx_entry *entry, unsigned value)
+{
+ entry->block = cpu_to_le32(value);
+}
+
+static inline unsigned dx_get_hash (struct dx_entry *entry)
+{
+ return le32_to_cpu(entry->hash);
+}
+
+static inline void dx_set_hash (struct dx_entry *entry, unsigned value)
+{
+ entry->hash = cpu_to_le32(value);
+}
+
+static inline unsigned dx_get_count (struct dx_entry *entries)
+{
+ return le16_to_cpu(((struct dx_countlimit *) entries)->count);
+}
+
+static inline unsigned dx_get_limit (struct dx_entry *entries)
+{
+ return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
+}
+
+static inline void dx_set_count (struct dx_entry *entries, unsigned value)
+{
+ ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
+}
+
+static inline void dx_set_limit (struct dx_entry *entries, unsigned value)
+{
+ ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
+}
+
+static inline unsigned dx_root_limit (struct inode *dir, unsigned infosize)
+{
+ unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
+ EXT4_DIR_REC_LEN(2) - infosize;
+ return 0? 20: entry_space / sizeof(struct dx_entry);
+}
+
+static inline unsigned dx_node_limit (struct inode *dir)
+{
+ unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
+ return 0? 22: entry_space / sizeof(struct dx_entry);
+}
+
+/*
+ * Debug
+ */
+#ifdef DX_DEBUG
+static void dx_show_index (char * label, struct dx_entry *entries)
+{
+ int i, n = dx_get_count (entries);
+ printk("%s index ", label);
+ for (i = 0; i < n; i++) {
+ printk("%x->%u ", i? dx_get_hash(entries + i) :
+ 0, dx_get_block(entries + i));
+ }
+ printk("\n");
+}
+
+struct stats
+{
+ unsigned names;
+ unsigned space;
+ unsigned bcount;
+};
+
+static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
+ int size, int show_names)
+{
+ unsigned names = 0, space = 0;
+ char *base = (char *) de;
+ struct dx_hash_info h = *hinfo;
+
+ printk("names: ");
+ while ((char *) de < base + size)
+ {
+ if (de->inode)
+ {
+ if (show_names)
+ {
+ int len = de->name_len;
+ char *name = de->name;
+ while (len--) printk("%c", *name++);
+ ext4fs_dirhash(de->name, de->name_len, &h);
+ printk(":%x.%u ", h.hash,
+ ((char *) de - base));
+ }
+ space += EXT4_DIR_REC_LEN(de->name_len);
+ names++;
+ }
+ de = (struct ext4_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
+ }
+ printk("(%i)\n", names);
+ return (struct stats) { names, space, 1 };
+}
+
+struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
+ struct dx_entry *entries, int levels)
+{
+ unsigned blocksize = dir->i_sb->s_blocksize;
+ unsigned count = dx_get_count (entries), names = 0, space = 0, i;
+ unsigned bcount = 0;
+ struct buffer_head *bh;
+ int err;
+ printk("%i indexed blocks...\n", count);
+ for (i = 0; i < count; i++, entries++)
+ {
+ u32 block = dx_get_block(entries), hash = i? dx_get_hash(entries): 0;
+ u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
+ struct stats stats;
+ printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
+ if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
+ stats = levels?
+ dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
+ dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
+ names += stats.names;
+ space += stats.space;
+ bcount += stats.bcount;
+ brelse (bh);
+ }
+ if (bcount)
+ printk("%snames %u, fullness %u (%u%%)\n", levels?"":" ",
+ names, space/bcount,(space/bcount)*100/blocksize);
+ return (struct stats) { names, space, bcount};
+}
+#endif /* DX_DEBUG */
+
+/*
+ * Probe for a directory leaf block to search.
+ *
+ * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
+ * error in the directory index, and the caller should fall back to
+ * searching the directory normally. The callers of dx_probe **MUST**
+ * check for this error code, and make sure it never gets reflected
+ * back to userspace.
+ */
+static struct dx_frame *
+dx_probe(struct dentry *dentry, struct inode *dir,
+ struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
+{
+ unsigned count, indirect;
+ struct dx_entry *at, *entries, *p, *q, *m;
+ struct dx_root *root;
+ struct buffer_head *bh;
+ struct dx_frame *frame = frame_in;
+ u32 hash;
+
+ frame->bh = NULL;
+ if (dentry)
+ dir = dentry->d_parent->d_inode;
+ if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
+ goto fail;
+ root = (struct dx_root *) bh->b_data;
+ if (root->info.hash_version != DX_HASH_TEA &&
+ root->info.hash_version != DX_HASH_HALF_MD4 &&
+ root->info.hash_version != DX_HASH_LEGACY) {
+ ext4_warning(dir->i_sb, __FUNCTION__,
+ "Unrecognised inode hash code %d",
+ root->info.hash_version);
+ brelse(bh);
+ *err = ERR_BAD_DX_DIR;
+ goto fail;
+ }
+ hinfo->hash_version = root->info.hash_version;
+ hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
+ if (dentry)
+ ext4fs_dirhash(dentry->d_name.name, dentry->d_name.len, hinfo);
+ hash = hinfo->hash;
+
+ if (root->info.unused_flags & 1) {
+ ext4_warning(dir->i_sb, __FUNCTION__,
+ "Unimplemented inode hash flags: %#06x",
+ root->info.unused_flags);
+ brelse(bh);
+ *err = ERR_BAD_DX_DIR;
+ goto fail;
+ }
+
+ if ((indirect = root->info.indirect_levels) > 1) {
+ ext4_warning(dir->i_sb, __FUNCTION__,
+ "Unimplemented inode hash depth: %#06x",
+ root->info.indirect_levels);
+ brelse(bh);
+ *err = ERR_BAD_DX_DIR;
+ goto fail;
+ }
+
+ entries = (struct dx_entry *) (((char *)&root->info) +
+ root->info.info_length);
+ assert(dx_get_limit(entries) == dx_root_limit(dir,
+ root->info.info_length));
+ dxtrace (printk("Look up %x", hash));
+ while (1)
+ {
+ count = dx_get_count(entries);
+ assert (count && count <= dx_get_limit(entries));
+ p = entries + 1;
+ q = entries + count - 1;
+ while (p <= q)
+ {
+ m = p + (q - p)/2;
+ dxtrace(printk("."));
+ if (dx_get_hash(m) > hash)
+ q = m - 1;
+ else
+ p = m + 1;
+ }
+
+ if (0) // linear search cross check
+ {
+ unsigned n = count - 1;
+ at = entries;
+ while (n--)
+ {
+ dxtrace(printk(","));
+ if (dx_get_hash(++at) > hash)
+ {
+ at--;
+ break;
+ }
+ }
+ assert (at == p - 1);
+ }
+
+ at = p - 1;
+ dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
+ frame->bh = bh;
+ frame->entries = entries;
+ frame->at = at;
+ if (!indirect--) return frame;
+ if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
+ goto fail2;
+ at = entries = ((struct dx_node *) bh->b_data)->entries;
+ assert (dx_get_limit(entries) == dx_node_limit (dir));
+ frame++;
+ }
+fail2:
+ while (frame >= frame_in) {
+ brelse(frame->bh);
+ frame--;
+ }
+fail:
+ return NULL;
+}
+
+static void dx_release (struct dx_frame *frames)
+{
+ if (frames[0].bh == NULL)
+ return;
+
+ if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
+ brelse(frames[1].bh);
+ brelse(frames[0].bh);
+}
+
+/*
+ * This function increments the frame pointer to search the next leaf
+ * block, and reads in the necessary intervening nodes if the search
+ * should be necessary. Whether or not the search is necessary is
+ * controlled by the hash parameter. If the hash value is even, then
+ * the search is only continued if the next block starts with that
+ * hash value. This is used if we are searching for a specific file.
+ *
+ * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
+ *
+ * This function returns 1 if the caller should continue to search,
+ * or 0 if it should not. If there is an error reading one of the
+ * index blocks, it will a negative error code.
+ *
+ * If start_hash is non-null, it will be filled in with the starting
+ * hash of the next page.
+ */
+static int ext4_htree_next_block(struct inode *dir, __u32 hash,
+ struct dx_frame *frame,
+ struct dx_frame *frames,
+ __u32 *start_hash)
+{
+ struct dx_frame *p;
+ struct buffer_head *bh;
+ int err, num_frames = 0;
+ __u32 bhash;
+
+ p = frame;
+ /*
+ * Find the next leaf page by incrementing the frame pointer.
+ * If we run out of entries in the interior node, loop around and
+ * increment pointer in the parent node. When we break out of
+ * this loop, num_frames indicates the number of interior
+ * nodes need to be read.
+ */
+ while (1) {
+ if (++(p->at) < p->entries + dx_get_count(p->entries))
+ break;
+ if (p == frames)
+ return 0;
+ num_frames++;
+ p--;
+ }
+
+ /*
+ * If the hash is 1, then continue only if the next page has a
+ * continuation hash of any value. This is used for readdir
+ * handling. Otherwise, check to see if the hash matches the
+ * desired contiuation hash. If it doesn't, return since
+ * there's no point to read in the successive index pages.
+ */
+ bhash = dx_get_hash(p->at);
+ if (start_hash)
+ *start_hash = bhash;
+ if ((hash & 1) == 0) {
+ if ((bhash & ~1) != hash)
+ return 0;
+ }
+ /*
+ * If the hash is HASH_NB_ALWAYS, we always go to the next
+ * block so no check is necessary
+ */
+ while (num_frames--) {
+ if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
+ 0, &err)))
+ return err; /* Failure */
+ p++;
+ brelse (p->bh);
+ p->bh = bh;
+ p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
+ }
+ return 1;
+}
+
+
+/*
+ * p is at least 6 bytes before the end of page
+ */
+static inline struct ext4_dir_entry_2 *ext4_next_entry(struct ext4_dir_entry_2 *p)
+{
+ return (struct ext4_dir_entry_2 *)((char*)p + le16_to_cpu(p->rec_len));
+}
+
+/*
+ * This function fills a red-black tree with information from a
+ * directory block. It returns the number directory entries loaded
+ * into the tree. If there is an error it is returned in err.
+ */
+static int htree_dirblock_to_tree(struct file *dir_file,
+ struct inode *dir, int block,
+ struct dx_hash_info *hinfo,
+ __u32 start_hash, __u32 start_minor_hash)
+{
+ struct buffer_head *bh;
+ struct ext4_dir_entry_2 *de, *top;
+ int err, count = 0;
+
+ dxtrace(printk("In htree dirblock_to_tree: block %d\n", block));
+ if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
+ return err;
+
+ de = (struct ext4_dir_entry_2 *) bh->b_data;
+ top = (struct ext4_dir_entry_2 *) ((char *) de +
+ dir->i_sb->s_blocksize -
+ EXT4_DIR_REC_LEN(0));
+ for (; de < top; de = ext4_next_entry(de)) {
+ if (!ext4_check_dir_entry("htree_dirblock_to_tree", dir, de, bh,
+ (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
+ +((char *)de - bh->b_data))) {
+ /* On error, skip the f_pos to the next block. */
+ dir_file->f_pos = (dir_file->f_pos |
+ (dir->i_sb->s_blocksize - 1)) + 1;
+ brelse (bh);
+ return count;
+ }
+ ext4fs_dirhash(de->name, de->name_len, hinfo);
+ if ((hinfo->hash < start_hash) ||
+ ((hinfo->hash == start_hash) &&
+ (hinfo->minor_hash < start_minor_hash)))
+ continue;
+ if (de->inode == 0)
+ continue;
+ if ((err = ext4_htree_store_dirent(dir_file,
+ hinfo->hash, hinfo->minor_hash, de)) != 0) {
+ brelse(bh);
+ return err;
+ }
+ count++;
+ }
+ brelse(bh);
+ return count;
+}
+
+
+/*
+ * This function fills a red-black tree with information from a
+ * directory. We start scanning the directory in hash order, starting
+ * at start_hash and start_minor_hash.
+ *
+ * This function returns the number of entries inserted into the tree,
+ * or a negative error code.
+ */
+int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
+ __u32 start_minor_hash, __u32 *next_hash)
+{
+ struct dx_hash_info hinfo;
+ struct ext4_dir_entry_2 *de;
+ struct dx_frame frames[2], *frame;
+ struct inode *dir;
+ int block, err;
+ int count = 0;
+ int ret;
+ __u32 hashval;
+
+ dxtrace(printk("In htree_fill_tree, start hash: %x:%x\n", start_hash,
+ start_minor_hash));
+ dir = dir_file->f_path.dentry->d_inode;
+ if (!(EXT4_I(dir)->i_flags & EXT4_INDEX_FL)) {
+ hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
+ hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
+ count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
+ start_hash, start_minor_hash);
+ *next_hash = ~0;
+ return count;
+ }
+ hinfo.hash = start_hash;
+ hinfo.minor_hash = 0;
+ frame = dx_probe(NULL, dir_file->f_path.dentry->d_inode, &hinfo, frames, &err);
+ if (!frame)
+ return err;
+
+ /* Add '.' and '..' from the htree header */
+ if (!start_hash && !start_minor_hash) {
+ de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
+ if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
+ goto errout;
+ count++;
+ }
+ if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
+ de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
+ de = ext4_next_entry(de);
+ if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
+ goto errout;
+ count++;
+ }
+
+ while (1) {
+ block = dx_get_block(frame->at);
+ ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
+ start_hash, start_minor_hash);
+ if (ret < 0) {
+ err = ret;
+ goto errout;
+ }
+ count += ret;
+ hashval = ~0;
+ ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
+ frame, frames, &hashval);
+ *next_hash = hashval;
+ if (ret < 0) {
+ err = ret;
+ goto errout;
+ }
+ /*
+ * Stop if: (a) there are no more entries, or
+ * (b) we have inserted at least one entry and the
+ * next hash value is not a continuation
+ */
+ if ((ret == 0) ||
+ (count && ((hashval & 1) == 0)))
+ break;
+ }
+ dx_release(frames);
+ dxtrace(printk("Fill tree: returned %d entries, next hash: %x\n",
+ count, *next_hash));
+ return count;
+errout:
+ dx_release(frames);
+ return (err);
+}
+
+
+/*
+ * Directory block splitting, compacting
+ */
+
+static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
+ struct dx_hash_info *hinfo, struct dx_map_entry *map_tail)
+{
+ int count = 0;
+ char *base = (char *) de;
+ struct dx_hash_info h = *hinfo;
+
+ while ((char *) de < base + size)
+ {
+ if (de->name_len && de->inode) {
+ ext4fs_dirhash(de->name, de->name_len, &h);
+ map_tail--;
+ map_tail->hash = h.hash;
+ map_tail->offs = (u32) ((char *) de - base);
+ count++;
+ cond_resched();
+ }
+ /* XXX: do we need to check rec_len == 0 case? -Chris */
+ de = (struct ext4_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
+ }
+ return count;
+}
+
+static void dx_sort_map (struct dx_map_entry *map, unsigned count)
+{
+ struct dx_map_entry *p, *q, *top = map + count - 1;
+ int more;
+ /* Combsort until bubble sort doesn't suck */
+ while (count > 2) {
+ count = count*10/13;
+ if (count - 9 < 2) /* 9, 10 -> 11 */
+ count = 11;
+ for (p = top, q = p - count; q >= map; p--, q--)
+ if (p->hash < q->hash)
+ swap(*p, *q);
+ }
+ /* Garden variety bubble sort */
+ do {
+ more = 0;
+ q = top;
+ while (q-- > map) {
+ if (q[1].hash >= q[0].hash)
+ continue;
+ swap(*(q+1), *q);
+ more = 1;
+ }
+ } while(more);
+}
+
+static void dx_insert_block(struct dx_frame *frame, u32 hash, u32 block)
+{
+ struct dx_entry *entries = frame->entries;
+ struct dx_entry *old = frame->at, *new = old + 1;
+ int count = dx_get_count(entries);
+
+ assert(count < dx_get_limit(entries));
+ assert(old < entries + count);
+ memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
+ dx_set_hash(new, hash);
+ dx_set_block(new, block);
+ dx_set_count(entries, count + 1);
+}
+#endif
+
+
+static void ext4_update_dx_flag(struct inode *inode)
+{
+ if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
+ EXT4_FEATURE_COMPAT_DIR_INDEX))
+ EXT4_I(inode)->i_flags &= ~EXT4_INDEX_FL;
+}
+
+/*
+ * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
+ *
+ * `len <= EXT4_NAME_LEN' is guaranteed by caller.
+ * `de != NULL' is guaranteed by caller.
+ */
+static inline int ext4_match (int len, const char * const name,
+ struct ext4_dir_entry_2 * de)
+{
+ if (len != de->name_len)
+ return 0;
+ if (!de->inode)
+ return 0;
+ return !memcmp(name, de->name, len);
+}
+
+/*
+ * Returns 0 if not found, -1 on failure, and 1 on success
+ */
+static inline int search_dirblock(struct buffer_head * bh,
+ struct inode *dir,
+ struct dentry *dentry,
+ unsigned long offset,
+ struct ext4_dir_entry_2 ** res_dir)
+{
+ struct ext4_dir_entry_2 * de;
+ char * dlimit;
+ int de_len;
+ const char *name = dentry->d_name.name;
+ int namelen = dentry->d_name.len;
+
+ de = (struct ext4_dir_entry_2 *) bh->b_data;
+ dlimit = bh->b_data + dir->i_sb->s_blocksize;
+ while ((char *) de < dlimit) {
+ /* this code is executed quadratically often */
+ /* do minimal checking `by hand' */
+
+ if ((char *) de + namelen <= dlimit &&
+ ext4_match (namelen, name, de)) {
+ /* found a match - just to be sure, do a full check */
+ if (!ext4_check_dir_entry("ext4_find_entry",
+ dir, de, bh, offset))
+ return -1;
+ *res_dir = de;
+ return 1;
+ }
+ /* prevent looping on a bad block */
+ de_len = le16_to_cpu(de->rec_len);
+ if (de_len <= 0)
+ return -1;
+ offset += de_len;
+ de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
+ }
+ return 0;
+}
+
+
+/*
+ * ext4_find_entry()
+ *
+ * finds an entry in the specified directory with the wanted name. It
+ * returns the cache buffer in which the entry was found, and the entry
+ * itself (as a parameter - res_dir). It does NOT read the inode of the
+ * entry - you'll have to do that yourself if you want to.
+ *
+ * The returned buffer_head has ->b_count elevated. The caller is expected
+ * to brelse() it when appropriate.
+ */
+static struct buffer_head * ext4_find_entry (struct dentry *dentry,
+ struct ext4_dir_entry_2 ** res_dir)
+{
+ struct super_block * sb;
+ struct buffer_head * bh_use[NAMEI_RA_SIZE];
+ struct buffer_head * bh, *ret = NULL;
+ unsigned long start, block, b;
+ int ra_max = 0; /* Number of bh's in the readahead
+ buffer, bh_use[] */
+ int ra_ptr = 0; /* Current index into readahead
+ buffer */
+ int num = 0;
+ int nblocks, i, err;
+ struct inode *dir = dentry->d_parent->d_inode;
+ int namelen;
+ const u8 *name;
+ unsigned blocksize;
+
+ *res_dir = NULL;
+ sb = dir->i_sb;
+ blocksize = sb->s_blocksize;
+ namelen = dentry->d_name.len;
+ name = dentry->d_name.name;
+ if (namelen > EXT4_NAME_LEN)
+ return NULL;
+#ifdef CONFIG_EXT4_INDEX
+ if (is_dx(dir)) {
+ bh = ext4_dx_find_entry(dentry, res_dir, &err);
+ /*
+ * On success, or if the error was file not found,
+ * return. Otherwise, fall back to doing a search the
+ * old fashioned way.
+ */
+ if (bh || (err != ERR_BAD_DX_DIR))
+ return bh;
+ dxtrace(printk("ext4_find_entry: dx failed, falling back\n"));
+ }
+#endif
+ nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
+ start = EXT4_I(dir)->i_dir_start_lookup;
+ if (start >= nblocks)
+ start = 0;
+ block = start;
+restart:
+ do {
+ /*
+ * We deal with the read-ahead logic here.
+ */
+ if (ra_ptr >= ra_max) {
+ /* Refill the readahead buffer */
+ ra_ptr = 0;
+ b = block;
+ for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
+ /*
+ * Terminate if we reach the end of the
+ * directory and must wrap, or if our
+ * search has finished at this block.
+ */
+ if (b >= nblocks || (num && block == start)) {
+ bh_use[ra_max] = NULL;
+ break;
+ }
+ num++;
+ bh = ext4_getblk(NULL, dir, b++, 0, &err);
+ bh_use[ra_max] = bh;
+ if (bh)
+ ll_rw_block(READ_META, 1, &bh);
+ }
+ }
+ if ((bh = bh_use[ra_ptr++]) == NULL)
+ goto next;
+ wait_on_buffer(bh);
+ if (!buffer_uptodate(bh)) {
+ /* read error, skip block & hope for the best */
+ ext4_error(sb, __FUNCTION__, "reading directory #%lu "
+ "offset %lu", dir->i_ino, block);
+ brelse(bh);
+ goto next;
+ }
+ i = search_dirblock(bh, dir, dentry,
+ block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
+ if (i == 1) {
+ EXT4_I(dir)->i_dir_start_lookup = block;
+ ret = bh;
+ goto cleanup_and_exit;
+ } else {
+ brelse(bh);
+ if (i < 0)
+ goto cleanup_and_exit;
+ }
+ next:
+ if (++block >= nblocks)
+ block = 0;
+ } while (block != start);
+
+ /*
+ * If the directory has grown while we were searching, then
+ * search the last part of the directory before giving up.
+ */
+ block = nblocks;
+ nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
+ if (block < nblocks) {
+ start = 0;
+ goto restart;
+ }
+
+cleanup_and_exit:
+ /* Clean up the read-ahead blocks */
+ for (; ra_ptr < ra_max; ra_ptr++)
+ brelse (bh_use[ra_ptr]);
+ return ret;
+}
+
+#ifdef CONFIG_EXT4_INDEX
+static struct buffer_head * ext4_dx_find_entry(struct dentry *dentry,
+ struct ext4_dir_entry_2 **res_dir, int *err)
+{
+ struct super_block * sb;
+ struct dx_hash_info hinfo;
+ u32 hash;
+ struct dx_frame frames[2], *frame;
+ struct ext4_dir_entry_2 *de, *top;
+ struct buffer_head *bh;
+ unsigned long block;
+ int retval;
+ int namelen = dentry->d_name.len;
+ const u8 *name = dentry->d_name.name;
+ struct inode *dir = dentry->d_parent->d_inode;
+
+ sb = dir->i_sb;
+ /* NFS may look up ".." - look at dx_root directory block */
+ if (namelen > 2 || name[0] != '.'||(name[1] != '.' && name[1] != '\0')){
+ if (!(frame = dx_probe(dentry, NULL, &hinfo, frames, err)))
+ return NULL;
+ } else {
+ frame = frames;
+ frame->bh = NULL; /* for dx_release() */
+ frame->at = (struct dx_entry *)frames; /* hack for zero entry*/
+ dx_set_block(frame->at, 0); /* dx_root block is 0 */
+ }
+ hash = hinfo.hash;
+ do {
+ block = dx_get_block(frame->at);
+ if (!(bh = ext4_bread (NULL,dir, block, 0, err)))
+ goto errout;
+ de = (struct ext4_dir_entry_2 *) bh->b_data;
+ top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize -
+ EXT4_DIR_REC_LEN(0));
+ for (; de < top; de = ext4_next_entry(de))
+ if (ext4_match (namelen, name, de)) {
+ if (!ext4_check_dir_entry("ext4_find_entry",
+ dir, de, bh,
+ (block<<EXT4_BLOCK_SIZE_BITS(sb))
+ +((char *)de - bh->b_data))) {
+ brelse (bh);
+ goto errout;
+ }
+ *res_dir = de;
+ dx_release (frames);
+ return bh;
+ }
+ brelse (bh);
+ /* Check to see if we should continue to search */
+ retval = ext4_htree_next_block(dir, hash, frame,
+ frames, NULL);
+ if (retval < 0) {
+ ext4_warning(sb, __FUNCTION__,
+ "error reading index page in directory #%lu",
+ dir->i_ino);
+ *err = retval;
+ goto errout;
+ }
+ } while (retval == 1);
+
+ *err = -ENOENT;
+errout:
+ dxtrace(printk("%s not found\n", name));
+ dx_release (frames);
+ return NULL;
+}
+#endif
+
+static struct dentry *ext4_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
+{
+ struct inode * inode;
+ struct ext4_dir_entry_2 * de;
+ struct buffer_head * bh;
+
+ if (dentry->d_name.len > EXT4_NAME_LEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ bh = ext4_find_entry(dentry, &de);
+ inode = NULL;
+ if (bh) {
+ unsigned long ino = le32_to_cpu(de->inode);
+ brelse (bh);
+ if (!ext4_valid_inum(dir->i_sb, ino)) {
+ ext4_error(dir->i_sb, "ext4_lookup",
+ "bad inode number: %lu", ino);
+ inode = NULL;
+ } else
+ inode = iget(dir->i_sb, ino);
+
+ if (!inode)
+ return ERR_PTR(-EACCES);
+ dx_propagate_tag(nd, inode);
+ }
+ return d_splice_alias(inode, dentry);
+}
+
+
+struct dentry *ext4_get_parent(struct dentry *child)
+{
+ unsigned long ino;
+ struct dentry *parent;
+ struct inode *inode;
+ struct dentry dotdot;
+ struct ext4_dir_entry_2 * de;
+ struct buffer_head *bh;
+
+ dotdot.d_name.name = "..";
+ dotdot.d_name.len = 2;
+ dotdot.d_parent = child; /* confusing, isn't it! */
+
+ bh = ext4_find_entry(&dotdot, &de);
+ inode = NULL;
+ if (!bh)
+ return ERR_PTR(-ENOENT);
+ ino = le32_to_cpu(de->inode);
+ brelse(bh);
+
+ if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
+ ext4_error(child->d_inode->i_sb, "ext4_get_parent",
+ "bad inode number: %lu", ino);
+ inode = NULL;
+ } else
+ inode = iget(child->d_inode->i_sb, ino);
+
+ if (!inode)
+ return ERR_PTR(-EACCES);
+
+ parent = d_alloc_anon(inode);
+ if (!parent) {
+ iput(inode);
+ parent = ERR_PTR(-ENOMEM);
+ }
+ return parent;
+}
+
+#define S_SHIFT 12
+static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
+ [S_IFREG >> S_SHIFT] = EXT4_FT_REG_FILE,
+ [S_IFDIR >> S_SHIFT] = EXT4_FT_DIR,
+ [S_IFCHR >> S_SHIFT] = EXT4_FT_CHRDEV,
+ [S_IFBLK >> S_SHIFT] = EXT4_FT_BLKDEV,
+ [S_IFIFO >> S_SHIFT] = EXT4_FT_FIFO,
+ [S_IFSOCK >> S_SHIFT] = EXT4_FT_SOCK,
+ [S_IFLNK >> S_SHIFT] = EXT4_FT_SYMLINK,
+};
+
+static inline void ext4_set_de_type(struct super_block *sb,
+ struct ext4_dir_entry_2 *de,
+ umode_t mode) {
+ if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
+ de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
+}
+
+#ifdef CONFIG_EXT4_INDEX
+static struct ext4_dir_entry_2 *
+dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
+{
+ unsigned rec_len = 0;
+
+ while (count--) {
+ struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) (from + map->offs);
+ rec_len = EXT4_DIR_REC_LEN(de->name_len);
+ memcpy (to, de, rec_len);
+ ((struct ext4_dir_entry_2 *) to)->rec_len =
+ cpu_to_le16(rec_len);
+ de->inode = 0;
+ map++;
+ to += rec_len;
+ }
+ return (struct ext4_dir_entry_2 *) (to - rec_len);
+}
+
+static struct ext4_dir_entry_2* dx_pack_dirents(char *base, int size)
+{
+ struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
+ unsigned rec_len = 0;
+
+ prev = to = de;
+ while ((char*)de < base + size) {
+ next = (struct ext4_dir_entry_2 *) ((char *) de +
+ le16_to_cpu(de->rec_len));
+ if (de->inode && de->name_len) {
+ rec_len = EXT4_DIR_REC_LEN(de->name_len);
+ if (de > to)
+ memmove(to, de, rec_len);
+ to->rec_len = cpu_to_le16(rec_len);
+ prev = to;
+ to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
+ }
+ de = next;
+ }
+ return prev;
+}
+
+static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
+ struct buffer_head **bh,struct dx_frame *frame,
+ struct dx_hash_info *hinfo, int *error)
+{
+ unsigned blocksize = dir->i_sb->s_blocksize;
+ unsigned count, continued;
+ struct buffer_head *bh2;
+ u32 newblock;
+ u32 hash2;
+ struct dx_map_entry *map;
+ char *data1 = (*bh)->b_data, *data2;
+ unsigned split;
+ struct ext4_dir_entry_2 *de = NULL, *de2;
+ int err;
+
+ bh2 = ext4_append (handle, dir, &newblock, error);
+ if (!(bh2)) {
+ brelse(*bh);
+ *bh = NULL;
+ goto errout;
+ }
+
+ BUFFER_TRACE(*bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, *bh);
+ if (err) {
+ journal_error:
+ brelse(*bh);
+ brelse(bh2);
+ *bh = NULL;
+ ext4_std_error(dir->i_sb, err);
+ goto errout;
+ }
+ BUFFER_TRACE(frame->bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, frame->bh);
+ if (err)
+ goto journal_error;
+
+ data2 = bh2->b_data;
+
+ /* create map in the end of data2 block */
+ map = (struct dx_map_entry *) (data2 + blocksize);
+ count = dx_make_map ((struct ext4_dir_entry_2 *) data1,
+ blocksize, hinfo, map);
+ map -= count;
+ split = count/2; // need to adjust to actual middle
+ dx_sort_map (map, count);
+ hash2 = map[split].hash;
+ continued = hash2 == map[split - 1].hash;
+ dxtrace(printk("Split block %i at %x, %i/%i\n",
+ dx_get_block(frame->at), hash2, split, count-split));
+
+ /* Fancy dance to stay within two buffers */
+ de2 = dx_move_dirents(data1, data2, map + split, count - split);
+ de = dx_pack_dirents(data1,blocksize);
+ de->rec_len = cpu_to_le16(data1 + blocksize - (char *) de);
+ de2->rec_len = cpu_to_le16(data2 + blocksize - (char *) de2);
+ dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
+ dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
+
+ /* Which block gets the new entry? */
+ if (hinfo->hash >= hash2)
+ {
+ swap(*bh, bh2);
+ de = de2;
+ }
+ dx_insert_block (frame, hash2 + continued, newblock);
+ err = ext4_journal_dirty_metadata (handle, bh2);
+ if (err)
+ goto journal_error;
+ err = ext4_journal_dirty_metadata (handle, frame->bh);
+ if (err)
+ goto journal_error;
+ brelse (bh2);
+ dxtrace(dx_show_index ("frame", frame->entries));
+errout:
+ return de;
+}
+#endif
+
+
+/*
+ * Add a new entry into a directory (leaf) block. If de is non-NULL,
+ * it points to a directory entry which is guaranteed to be large
+ * enough for new directory entry. If de is NULL, then
+ * add_dirent_to_buf will attempt search the directory block for
+ * space. It will return -ENOSPC if no space is available, and -EIO
+ * and -EEXIST if directory entry already exists.
+ *
+ * NOTE! bh is NOT released in the case where ENOSPC is returned. In
+ * all other cases bh is released.
+ */
+static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
+ struct inode *inode, struct ext4_dir_entry_2 *de,
+ struct buffer_head * bh)
+{
+ struct inode *dir = dentry->d_parent->d_inode;
+ const char *name = dentry->d_name.name;
+ int namelen = dentry->d_name.len;
+ unsigned long offset = 0;
+ unsigned short reclen;
+ int nlen, rlen, err;
+ char *top;
+
+ reclen = EXT4_DIR_REC_LEN(namelen);
+ if (!de) {
+ de = (struct ext4_dir_entry_2 *)bh->b_data;
+ top = bh->b_data + dir->i_sb->s_blocksize - reclen;
+ while ((char *) de <= top) {
+ if (!ext4_check_dir_entry("ext4_add_entry", dir, de,
+ bh, offset)) {
+ brelse (bh);
+ return -EIO;
+ }
+ if (ext4_match (namelen, name, de)) {
+ brelse (bh);
+ return -EEXIST;
+ }
+ nlen = EXT4_DIR_REC_LEN(de->name_len);
+ rlen = le16_to_cpu(de->rec_len);
+ if ((de->inode? rlen - nlen: rlen) >= reclen)
+ break;
+ de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
+ offset += rlen;
+ }
+ if ((char *) de > top)
+ return -ENOSPC;
+ }
+ BUFFER_TRACE(bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, bh);
+ if (err) {
+ ext4_std_error(dir->i_sb, err);
+ brelse(bh);
+ return err;
+ }
+
+ /* By now the buffer is marked for journaling */
+ nlen = EXT4_DIR_REC_LEN(de->name_len);
+ rlen = le16_to_cpu(de->rec_len);
+ if (de->inode) {
+ struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
+ de1->rec_len = cpu_to_le16(rlen - nlen);
+ de->rec_len = cpu_to_le16(nlen);
+ de = de1;
+ }
+ de->file_type = EXT4_FT_UNKNOWN;
+ if (inode) {
+ de->inode = cpu_to_le32(inode->i_ino);
+ ext4_set_de_type(dir->i_sb, de, inode->i_mode);
+ } else
+ de->inode = 0;
+ de->name_len = namelen;
+ memcpy (de->name, name, namelen);
+ /*
+ * XXX shouldn't update any times until successful
+ * completion of syscall, but too many callers depend
+ * on this.
+ *
+ * XXX similarly, too many callers depend on
+ * ext4_new_inode() setting the times, but error
+ * recovery deletes the inode, so the worst that can
+ * happen is that the times are slightly out of date
+ * and/or different from the directory change time.
+ */
+ dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
+ ext4_update_dx_flag(dir);
+ dir->i_version++;
+ ext4_mark_inode_dirty(handle, dir);
+ BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
+ err = ext4_journal_dirty_metadata(handle, bh);
+ if (err)
+ ext4_std_error(dir->i_sb, err);
+ brelse(bh);
+ return 0;
+}
+
+#ifdef CONFIG_EXT4_INDEX
+/*
+ * This converts a one block unindexed directory to a 3 block indexed
+ * directory, and adds the dentry to the indexed directory.
+ */
+static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
+ struct inode *inode, struct buffer_head *bh)
+{
+ struct inode *dir = dentry->d_parent->d_inode;
+ const char *name = dentry->d_name.name;
+ int namelen = dentry->d_name.len;
+ struct buffer_head *bh2;
+ struct dx_root *root;
+ struct dx_frame frames[2], *frame;
+ struct dx_entry *entries;
+ struct ext4_dir_entry_2 *de, *de2;
+ char *data1, *top;
+ unsigned len;
+ int retval;
+ unsigned blocksize;
+ struct dx_hash_info hinfo;
+ u32 block;
+ struct fake_dirent *fde;
+
+ blocksize = dir->i_sb->s_blocksize;
+ dxtrace(printk("Creating index\n"));
+ retval = ext4_journal_get_write_access(handle, bh);
+ if (retval) {
+ ext4_std_error(dir->i_sb, retval);
+ brelse(bh);
+ return retval;
+ }
+ root = (struct dx_root *) bh->b_data;
+
+ bh2 = ext4_append (handle, dir, &block, &retval);
+ if (!(bh2)) {
+ brelse(bh);
+ return retval;
+ }
+ EXT4_I(dir)->i_flags |= EXT4_INDEX_FL;
+ data1 = bh2->b_data;
+
+ /* The 0th block becomes the root, move the dirents out */
+ fde = &root->dotdot;
+ de = (struct ext4_dir_entry_2 *)((char *)fde + le16_to_cpu(fde->rec_len));
+ len = ((char *) root) + blocksize - (char *) de;
+ memcpy (data1, de, len);
+ de = (struct ext4_dir_entry_2 *) data1;
+ top = data1 + len;
+ while ((char *)(de2=(void*)de+le16_to_cpu(de->rec_len)) < top)
+ de = de2;
+ de->rec_len = cpu_to_le16(data1 + blocksize - (char *) de);
+ /* Initialize the root; the dot dirents already exist */
+ de = (struct ext4_dir_entry_2 *) (&root->dotdot);
+ de->rec_len = cpu_to_le16(blocksize - EXT4_DIR_REC_LEN(2));
+ memset (&root->info, 0, sizeof(root->info));
+ root->info.info_length = sizeof(root->info);
+ root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
+ entries = root->entries;
+ dx_set_block (entries, 1);
+ dx_set_count (entries, 1);
+ dx_set_limit (entries, dx_root_limit(dir, sizeof(root->info)));
+
+ /* Initialize as for dx_probe */
+ hinfo.hash_version = root->info.hash_version;
+ hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
+ ext4fs_dirhash(name, namelen, &hinfo);
+ frame = frames;
+ frame->entries = entries;
+ frame->at = entries;
+ frame->bh = bh;
+ bh = bh2;
+ de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
+ dx_release (frames);
+ if (!(de))
+ return retval;
+
+ return add_dirent_to_buf(handle, dentry, inode, de, bh);
+}
+#endif
+
+/*
+ * ext4_add_entry()
+ *
+ * adds a file entry to the specified directory, using the same
+ * semantics as ext4_find_entry(). It returns NULL if it failed.
+ *
+ * NOTE!! The inode part of 'de' is left at 0 - which means you
+ * may not sleep between calling this and putting something into
+ * the entry, as someone else might have used it while you slept.
+ */
+static int ext4_add_entry (handle_t *handle, struct dentry *dentry,
+ struct inode *inode)
+{
+ struct inode *dir = dentry->d_parent->d_inode;
+ unsigned long offset;
+ struct buffer_head * bh;
+ struct ext4_dir_entry_2 *de;
+ struct super_block * sb;
+ int retval;
+#ifdef CONFIG_EXT4_INDEX
+ int dx_fallback=0;
+#endif
+ unsigned blocksize;
+ u32 block, blocks;
+
+ sb = dir->i_sb;
+ blocksize = sb->s_blocksize;
+ if (!dentry->d_name.len)
+ return -EINVAL;
+#ifdef CONFIG_EXT4_INDEX
+ if (is_dx(dir)) {
+ retval = ext4_dx_add_entry(handle, dentry, inode);
+ if (!retval || (retval != ERR_BAD_DX_DIR))
+ return retval;
+ EXT4_I(dir)->i_flags &= ~EXT4_INDEX_FL;
+ dx_fallback++;
+ ext4_mark_inode_dirty(handle, dir);
+ }
+#endif
+ blocks = dir->i_size >> sb->s_blocksize_bits;
+ for (block = 0, offset = 0; block < blocks; block++) {
+ bh = ext4_bread(handle, dir, block, 0, &retval);
+ if(!bh)
+ return retval;
+ retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
+ if (retval != -ENOSPC)
+ return retval;
+
+#ifdef CONFIG_EXT4_INDEX
+ if (blocks == 1 && !dx_fallback &&
+ EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
+ return make_indexed_dir(handle, dentry, inode, bh);
+#endif
+ brelse(bh);
+ }
+ bh = ext4_append(handle, dir, &block, &retval);
+ if (!bh)
+ return retval;
+ de = (struct ext4_dir_entry_2 *) bh->b_data;
+ de->inode = 0;
+ de->rec_len = cpu_to_le16(blocksize);
+ return add_dirent_to_buf(handle, dentry, inode, de, bh);
+}
+
+#ifdef CONFIG_EXT4_INDEX
+/*
+ * Returns 0 for success, or a negative error value
+ */
+static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
+ struct inode *inode)
+{
+ struct dx_frame frames[2], *frame;
+ struct dx_entry *entries, *at;
+ struct dx_hash_info hinfo;
+ struct buffer_head * bh;
+ struct inode *dir = dentry->d_parent->d_inode;
+ struct super_block * sb = dir->i_sb;
+ struct ext4_dir_entry_2 *de;
+ int err;
+
+ frame = dx_probe(dentry, NULL, &hinfo, frames, &err);
+ if (!frame)
+ return err;
+ entries = frame->entries;
+ at = frame->at;
+
+ if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
+ goto cleanup;
+
+ BUFFER_TRACE(bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, bh);
+ if (err)
+ goto journal_error;
+
+ err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
+ if (err != -ENOSPC) {
+ bh = NULL;
+ goto cleanup;
+ }
+
+ /* Block full, should compress but for now just split */
+ dxtrace(printk("using %u of %u node entries\n",
+ dx_get_count(entries), dx_get_limit(entries)));
+ /* Need to split index? */
+ if (dx_get_count(entries) == dx_get_limit(entries)) {
+ u32 newblock;
+ unsigned icount = dx_get_count(entries);
+ int levels = frame - frames;
+ struct dx_entry *entries2;
+ struct dx_node *node2;
+ struct buffer_head *bh2;
+
+ if (levels && (dx_get_count(frames->entries) ==
+ dx_get_limit(frames->entries))) {
+ ext4_warning(sb, __FUNCTION__,
+ "Directory index full!");
+ err = -ENOSPC;
+ goto cleanup;
+ }
+ bh2 = ext4_append (handle, dir, &newblock, &err);
+ if (!(bh2))
+ goto cleanup;
+ node2 = (struct dx_node *)(bh2->b_data);
+ entries2 = node2->entries;
+ node2->fake.rec_len = cpu_to_le16(sb->s_blocksize);
+ node2->fake.inode = 0;
+ BUFFER_TRACE(frame->bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, frame->bh);
+ if (err)
+ goto journal_error;
+ if (levels) {
+ unsigned icount1 = icount/2, icount2 = icount - icount1;
+ unsigned hash2 = dx_get_hash(entries + icount1);
+ dxtrace(printk("Split index %i/%i\n", icount1, icount2));
+
+ BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
+ err = ext4_journal_get_write_access(handle,
+ frames[0].bh);
+ if (err)
+ goto journal_error;
+
+ memcpy ((char *) entries2, (char *) (entries + icount1),
+ icount2 * sizeof(struct dx_entry));
+ dx_set_count (entries, icount1);
+ dx_set_count (entries2, icount2);
+ dx_set_limit (entries2, dx_node_limit(dir));
+
+ /* Which index block gets the new entry? */
+ if (at - entries >= icount1) {
+ frame->at = at = at - entries - icount1 + entries2;
+ frame->entries = entries = entries2;
+ swap(frame->bh, bh2);
+ }
+ dx_insert_block (frames + 0, hash2, newblock);
+ dxtrace(dx_show_index ("node", frames[1].entries));
+ dxtrace(dx_show_index ("node",
+ ((struct dx_node *) bh2->b_data)->entries));
+ err = ext4_journal_dirty_metadata(handle, bh2);
+ if (err)
+ goto journal_error;
+ brelse (bh2);
+ } else {
+ dxtrace(printk("Creating second level index...\n"));
+ memcpy((char *) entries2, (char *) entries,
+ icount * sizeof(struct dx_entry));
+ dx_set_limit(entries2, dx_node_limit(dir));
+
+ /* Set up root */
+ dx_set_count(entries, 1);
+ dx_set_block(entries + 0, newblock);
+ ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
+
+ /* Add new access path frame */
+ frame = frames + 1;
+ frame->at = at = at - entries + entries2;
+ frame->entries = entries = entries2;
+ frame->bh = bh2;
+ err = ext4_journal_get_write_access(handle,
+ frame->bh);
+ if (err)
+ goto journal_error;
+ }
+ ext4_journal_dirty_metadata(handle, frames[0].bh);
+ }
+ de = do_split(handle, dir, &bh, frame, &hinfo, &err);
+ if (!de)
+ goto cleanup;
+ err = add_dirent_to_buf(handle, dentry, inode, de, bh);
+ bh = NULL;
+ goto cleanup;
+
+journal_error:
+ ext4_std_error(dir->i_sb, err);
+cleanup:
+ if (bh)
+ brelse(bh);
+ dx_release(frames);
+ return err;
+}
+#endif
+
+/*
+ * ext4_delete_entry deletes a directory entry by merging it with the
+ * previous entry
+ */
+static int ext4_delete_entry (handle_t *handle,
+ struct inode * dir,
+ struct ext4_dir_entry_2 * de_del,
+ struct buffer_head * bh)
+{
+ struct ext4_dir_entry_2 * de, * pde;
+ int i;
+
+ i = 0;
+ pde = NULL;
+ de = (struct ext4_dir_entry_2 *) bh->b_data;
+ while (i < bh->b_size) {
+ if (!ext4_check_dir_entry("ext4_delete_entry", dir, de, bh, i))
+ return -EIO;
+ if (de == de_del) {
+ BUFFER_TRACE(bh, "get_write_access");
+ ext4_journal_get_write_access(handle, bh);
+ if (pde)
+ pde->rec_len =
+ cpu_to_le16(le16_to_cpu(pde->rec_len) +
+ le16_to_cpu(de->rec_len));
+ else
+ de->inode = 0;
+ dir->i_version++;
+ BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
+ ext4_journal_dirty_metadata(handle, bh);
+ return 0;
+ }
+ i += le16_to_cpu(de->rec_len);
+ pde = de;
+ de = (struct ext4_dir_entry_2 *)
+ ((char *) de + le16_to_cpu(de->rec_len));
+ }
+ return -ENOENT;
+}
+
+/*
+ * ext4_mark_inode_dirty is somewhat expensive, so unlike ext2 we
+ * do not perform it in these functions. We perform it at the call site,
+ * if it is needed.
+ */
+static inline void ext4_inc_count(handle_t *handle, struct inode *inode)
+{
+ inc_nlink(inode);
+}
+
+static inline void ext4_dec_count(handle_t *handle, struct inode *inode)
+{
+ drop_nlink(inode);
+}
+
+static int ext4_add_nondir(handle_t *handle,
+ struct dentry *dentry, struct inode *inode)
+{
+ int err = ext4_add_entry(handle, dentry, inode);
+ if (!err) {
+ ext4_mark_inode_dirty(handle, inode);
+ d_instantiate(dentry, inode);
+ return 0;
+ }
+ ext4_dec_count(handle, inode);
+ iput(inode);
+ return err;
+}
+
+/*
+ * By the time this is called, we already have created
+ * the directory cache entry for the new file, but it
+ * is so far negative - it has no inode.
+ *
+ * If the create succeeds, we fill in the inode information
+ * with d_instantiate().
+ */
+static int ext4_create (struct inode * dir, struct dentry * dentry, int mode,
+ struct nameidata *nd)
+{
+ handle_t *handle;
+ struct inode * inode;
+ int err, retries = 0;
+
+retry:
+ handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+ EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
+ 2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ if (IS_DIRSYNC(dir))
+ handle->h_sync = 1;
+
+ inode = ext4_new_inode (handle, dir, mode);
+ err = PTR_ERR(inode);
+ if (!IS_ERR(inode)) {
+ inode->i_op = &ext4_file_inode_operations;
+ inode->i_fop = &ext4_file_operations;
+ ext4_set_aops(inode);
+ err = ext4_add_nondir(handle, dentry, inode);
+ }
+ ext4_journal_stop(handle);
+ if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
+ goto retry;
+ return err;
+}
+
+static int ext4_mknod (struct inode * dir, struct dentry *dentry,
+ int mode, dev_t rdev)
+{
+ handle_t *handle;
+ struct inode *inode;
+ int err, retries = 0;
+
+ if (!new_valid_dev(rdev))
+ return -EINVAL;
+
+retry:
+ handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+ EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
+ 2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ if (IS_DIRSYNC(dir))
+ handle->h_sync = 1;
+
+ inode = ext4_new_inode (handle, dir, mode);
+ err = PTR_ERR(inode);
+ if (!IS_ERR(inode)) {
+ init_special_inode(inode, inode->i_mode, rdev);
+#ifdef CONFIG_EXT4DEV_FS_XATTR
+ inode->i_op = &ext4_special_inode_operations;
+#endif
+ err = ext4_add_nondir(handle, dentry, inode);
+ }
+ ext4_journal_stop(handle);
+ if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
+ goto retry;
+ return err;
+}
+
+static int ext4_mkdir(struct inode * dir, struct dentry * dentry, int mode)
+{
+ handle_t *handle;
+ struct inode * inode;
+ struct buffer_head * dir_block;
+ struct ext4_dir_entry_2 * de;
+ int err, retries = 0;
+
+ if (dir->i_nlink >= EXT4_LINK_MAX)
+ return -EMLINK;
+
+retry:
+ handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+ EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
+ 2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ if (IS_DIRSYNC(dir))
+ handle->h_sync = 1;
+
+ inode = ext4_new_inode (handle, dir, S_IFDIR | mode);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_stop;
+
+ inode->i_op = &ext4_dir_inode_operations;
+ inode->i_fop = &ext4_dir_operations;
+ inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
+ dir_block = ext4_bread (handle, inode, 0, 1, &err);
+ if (!dir_block) {
+ drop_nlink(inode); /* is this nlink == 0? */
+ ext4_mark_inode_dirty(handle, inode);
+ iput (inode);
+ goto out_stop;
+ }
+ BUFFER_TRACE(dir_block, "get_write_access");
+ ext4_journal_get_write_access(handle, dir_block);
+ de = (struct ext4_dir_entry_2 *) dir_block->b_data;
+ de->inode = cpu_to_le32(inode->i_ino);
+ de->name_len = 1;
+ de->rec_len = cpu_to_le16(EXT4_DIR_REC_LEN(de->name_len));
+ strcpy (de->name, ".");
+ ext4_set_de_type(dir->i_sb, de, S_IFDIR);
+ de = (struct ext4_dir_entry_2 *)
+ ((char *) de + le16_to_cpu(de->rec_len));
+ de->inode = cpu_to_le32(dir->i_ino);
+ de->rec_len = cpu_to_le16(inode->i_sb->s_blocksize-EXT4_DIR_REC_LEN(1));
+ de->name_len = 2;
+ strcpy (de->name, "..");
+ ext4_set_de_type(dir->i_sb, de, S_IFDIR);
+ inode->i_nlink = 2;
+ BUFFER_TRACE(dir_block, "call ext4_journal_dirty_metadata");
+ ext4_journal_dirty_metadata(handle, dir_block);
+ brelse (dir_block);
+ ext4_mark_inode_dirty(handle, inode);
+ err = ext4_add_entry (handle, dentry, inode);
+ if (err) {
+ inode->i_nlink = 0;
+ ext4_mark_inode_dirty(handle, inode);
+ iput (inode);
+ goto out_stop;
+ }
+ inc_nlink(dir);
+ ext4_update_dx_flag(dir);
+ ext4_mark_inode_dirty(handle, dir);
+ d_instantiate(dentry, inode);
+out_stop:
+ ext4_journal_stop(handle);
+ if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
+ goto retry;
+ return err;
+}
+
+/*
+ * routine to check that the specified directory is empty (for rmdir)
+ */
+static int empty_dir (struct inode * inode)
+{
+ unsigned long offset;
+ struct buffer_head * bh;
+ struct ext4_dir_entry_2 * de, * de1;
+ struct super_block * sb;
+ int err = 0;
+
+ sb = inode->i_sb;
+ if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
+ !(bh = ext4_bread (NULL, inode, 0, 0, &err))) {
+ if (err)
+ ext4_error(inode->i_sb, __FUNCTION__,
+ "error %d reading directory #%lu offset 0",
+ err, inode->i_ino);
+ else
+ ext4_warning(inode->i_sb, __FUNCTION__,
+ "bad directory (dir #%lu) - no data block",
+ inode->i_ino);
+ return 1;
+ }
+ de = (struct ext4_dir_entry_2 *) bh->b_data;
+ de1 = (struct ext4_dir_entry_2 *)
+ ((char *) de + le16_to_cpu(de->rec_len));
+ if (le32_to_cpu(de->inode) != inode->i_ino ||
+ !le32_to_cpu(de1->inode) ||
+ strcmp (".", de->name) ||
+ strcmp ("..", de1->name)) {
+ ext4_warning (inode->i_sb, "empty_dir",
+ "bad directory (dir #%lu) - no `.' or `..'",
+ inode->i_ino);
+ brelse (bh);
+ return 1;
+ }
+ offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len);
+ de = (struct ext4_dir_entry_2 *)
+ ((char *) de1 + le16_to_cpu(de1->rec_len));
+ while (offset < inode->i_size ) {
+ if (!bh ||
+ (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
+ err = 0;
+ brelse (bh);
+ bh = ext4_bread (NULL, inode,
+ offset >> EXT4_BLOCK_SIZE_BITS(sb), 0, &err);
+ if (!bh) {
+ if (err)
+ ext4_error(sb, __FUNCTION__,
+ "error %d reading directory"
+ " #%lu offset %lu",
+ err, inode->i_ino, offset);
+ offset += sb->s_blocksize;
+ continue;
+ }
+ de = (struct ext4_dir_entry_2 *) bh->b_data;
+ }
+ if (!ext4_check_dir_entry("empty_dir", inode, de, bh, offset)) {
+ de = (struct ext4_dir_entry_2 *)(bh->b_data +
+ sb->s_blocksize);
+ offset = (offset | (sb->s_blocksize - 1)) + 1;
+ continue;
+ }
+ if (le32_to_cpu(de->inode)) {
+ brelse (bh);
+ return 0;
+ }
+ offset += le16_to_cpu(de->rec_len);
+ de = (struct ext4_dir_entry_2 *)
+ ((char *) de + le16_to_cpu(de->rec_len));
+ }
+ brelse (bh);
+ return 1;
+}
+
+/* ext4_orphan_add() links an unlinked or truncated inode into a list of
+ * such inodes, starting at the superblock, in case we crash before the
+ * file is closed/deleted, or in case the inode truncate spans multiple
+ * transactions and the last transaction is not recovered after a crash.
+ *
+ * At filesystem recovery time, we walk this list deleting unlinked
+ * inodes and truncating linked inodes in ext4_orphan_cleanup().
+ */
+int ext4_orphan_add(handle_t *handle, struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct ext4_iloc iloc;
+ int err = 0, rc;
+
+ lock_super(sb);
+ if (!list_empty(&EXT4_I(inode)->i_orphan))
+ goto out_unlock;
+
+ /* Orphan handling is only valid for files with data blocks
+ * being truncated, or files being unlinked. */
+
+ /* @@@ FIXME: Observation from aviro:
+ * I think I can trigger J_ASSERT in ext4_orphan_add(). We block
+ * here (on lock_super()), so race with ext4_link() which might bump
+ * ->i_nlink. For, say it, character device. Not a regular file,
+ * not a directory, not a symlink and ->i_nlink > 0.
+ */
+ J_ASSERT ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+ S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
+
+ BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
+ if (err)
+ goto out_unlock;
+
+ err = ext4_reserve_inode_write(handle, inode, &iloc);
+ if (err)
+ goto out_unlock;
+
+ /* Insert this inode at the head of the on-disk orphan list... */
+ NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
+ EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
+ err = ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh);
+ rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
+ if (!err)
+ err = rc;
+
+ /* Only add to the head of the in-memory list if all the
+ * previous operations succeeded. If the orphan_add is going to
+ * fail (possibly taking the journal offline), we can't risk
+ * leaving the inode on the orphan list: stray orphan-list
+ * entries can cause panics at unmount time.
+ *
+ * This is safe: on error we're going to ignore the orphan list
+ * anyway on the next recovery. */
+ if (!err)
+ list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
+
+ jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
+ jbd_debug(4, "orphan inode %lu will point to %d\n",
+ inode->i_ino, NEXT_ORPHAN(inode));
+out_unlock:
+ unlock_super(sb);
+ ext4_std_error(inode->i_sb, err);
+ return err;
+}
+
+/*
+ * ext4_orphan_del() removes an unlinked or truncated inode from the list
+ * of such inodes stored on disk, because it is finally being cleaned up.
+ */
+int ext4_orphan_del(handle_t *handle, struct inode *inode)
+{
+ struct list_head *prev;
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_sb_info *sbi;
+ unsigned long ino_next;
+ struct ext4_iloc iloc;
+ int err = 0;
+
+ lock_super(inode->i_sb);
+ if (list_empty(&ei->i_orphan)) {
+ unlock_super(inode->i_sb);
+ return 0;
+ }
+
+ ino_next = NEXT_ORPHAN(inode);
+ prev = ei->i_orphan.prev;
+ sbi = EXT4_SB(inode->i_sb);
+
+ jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
+
+ list_del_init(&ei->i_orphan);
+
+ /* If we're on an error path, we may not have a valid
+ * transaction handle with which to update the orphan list on
+ * disk, but we still need to remove the inode from the linked
+ * list in memory. */
+ if (!handle)
+ goto out;
+
+ err = ext4_reserve_inode_write(handle, inode, &iloc);
+ if (err)
+ goto out_err;
+
+ if (prev == &sbi->s_orphan) {
+ jbd_debug(4, "superblock will point to %lu\n", ino_next);
+ BUFFER_TRACE(sbi->s_sbh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, sbi->s_sbh);
+ if (err)
+ goto out_brelse;
+ sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
+ err = ext4_journal_dirty_metadata(handle, sbi->s_sbh);
+ } else {
+ struct ext4_iloc iloc2;
+ struct inode *i_prev =
+ &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
+
+ jbd_debug(4, "orphan inode %lu will point to %lu\n",
+ i_prev->i_ino, ino_next);
+ err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
+ if (err)
+ goto out_brelse;
+ NEXT_ORPHAN(i_prev) = ino_next;
+ err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
+ }
+ if (err)
+ goto out_brelse;
+ NEXT_ORPHAN(inode) = 0;
+ err = ext4_mark_iloc_dirty(handle, inode, &iloc);
+
+out_err:
+ ext4_std_error(inode->i_sb, err);
+out:
+ unlock_super(inode->i_sb);
+ return err;
+
+out_brelse:
+ brelse(iloc.bh);
+ goto out_err;
+}
+
+static int ext4_rmdir (struct inode * dir, struct dentry *dentry)
+{
+ int retval;
+ struct inode * inode;
+ struct buffer_head * bh;
+ struct ext4_dir_entry_2 * de;
+ handle_t *handle;
+
+ /* Initialize quotas before so that eventual writes go in
+ * separate transaction */
+ DQUOT_INIT(dentry->d_inode);
+ handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ retval = -ENOENT;
+ bh = ext4_find_entry (dentry, &de);
+ if (!bh)
+ goto end_rmdir;
+
+ if (IS_DIRSYNC(dir))
+ handle->h_sync = 1;
+
+ inode = dentry->d_inode;
+
+ retval = -EIO;
+ if (le32_to_cpu(de->inode) != inode->i_ino)
+ goto end_rmdir;
+
+ retval = -ENOTEMPTY;
+ if (!empty_dir (inode))
+ goto end_rmdir;
+
+ retval = ext4_delete_entry(handle, dir, de, bh);
+ if (retval)
+ goto end_rmdir;
+ if (inode->i_nlink != 2)
+ ext4_warning (inode->i_sb, "ext4_rmdir",
+ "empty directory has nlink!=2 (%d)",
+ inode->i_nlink);
+ inode->i_version++;
+ clear_nlink(inode);
+ /* There's no need to set i_disksize: the fact that i_nlink is
+ * zero will ensure that the right thing happens during any
+ * recovery. */
+ inode->i_size = 0;
+ ext4_orphan_add(handle, inode);
+ inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
+ ext4_mark_inode_dirty(handle, inode);
+ drop_nlink(dir);
+ ext4_update_dx_flag(dir);
+ ext4_mark_inode_dirty(handle, dir);
+
+end_rmdir:
+ ext4_journal_stop(handle);
+ brelse (bh);
+ return retval;
+}
+
+static int ext4_unlink(struct inode * dir, struct dentry *dentry)
+{
+ int retval;
+ struct inode * inode;
+ struct buffer_head * bh;
+ struct ext4_dir_entry_2 * de;
+ handle_t *handle;
+
+ /* Initialize quotas before so that eventual writes go
+ * in separate transaction */
+ DQUOT_INIT(dentry->d_inode);
+ handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ if (IS_DIRSYNC(dir))
+ handle->h_sync = 1;
+
+ retval = -ENOENT;
+ bh = ext4_find_entry (dentry, &de);
+ if (!bh)
+ goto end_unlink;
+
+ inode = dentry->d_inode;
+
+ retval = -EIO;
+ if (le32_to_cpu(de->inode) != inode->i_ino)
+ goto end_unlink;
+
+ if (!inode->i_nlink) {
+ ext4_warning (inode->i_sb, "ext4_unlink",
+ "Deleting nonexistent file (%lu), %d",
+ inode->i_ino, inode->i_nlink);
+ inode->i_nlink = 1;
+ }
+ retval = ext4_delete_entry(handle, dir, de, bh);
+ if (retval)
+ goto end_unlink;
+ dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
+ ext4_update_dx_flag(dir);
+ ext4_mark_inode_dirty(handle, dir);
+ drop_nlink(inode);
+ if (!inode->i_nlink)
+ ext4_orphan_add(handle, inode);
+ inode->i_ctime = dir->i_ctime;
+ ext4_mark_inode_dirty(handle, inode);
+ retval = 0;
+
+end_unlink:
+ ext4_journal_stop(handle);
+ brelse (bh);
+ return retval;
+}
+
+static int ext4_symlink (struct inode * dir,
+ struct dentry *dentry, const char * symname)
+{
+ handle_t *handle;
+ struct inode * inode;
+ int l, err, retries = 0;
+
+ l = strlen(symname)+1;
+ if (l > dir->i_sb->s_blocksize)
+ return -ENAMETOOLONG;
+
+retry:
+ handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+ EXT4_INDEX_EXTRA_TRANS_BLOCKS + 5 +
+ 2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ if (IS_DIRSYNC(dir))
+ handle->h_sync = 1;
+
+ inode = ext4_new_inode (handle, dir, S_IFLNK|S_IRWXUGO);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_stop;
+
+ if (l > sizeof (EXT4_I(inode)->i_data)) {
+ inode->i_op = &ext4_symlink_inode_operations;
+ ext4_set_aops(inode);
+ /*
+ * page_symlink() calls into ext4_prepare/commit_write.
+ * We have a transaction open. All is sweetness. It also sets
+ * i_size in generic_commit_write().
+ */
+ err = __page_symlink(inode, symname, l,
+ mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
+ if (err) {
+ ext4_dec_count(handle, inode);
+ ext4_mark_inode_dirty(handle, inode);
+ iput (inode);
+ goto out_stop;
+ }
+ } else {
+ inode->i_op = &ext4_fast_symlink_inode_operations;
+ memcpy((char*)&EXT4_I(inode)->i_data,symname,l);
+ inode->i_size = l-1;
+ }
+ EXT4_I(inode)->i_disksize = inode->i_size;
+ err = ext4_add_nondir(handle, dentry, inode);
+out_stop:
+ ext4_journal_stop(handle);
+ if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
+ goto retry;
+ return err;
+}
+
+static int ext4_link (struct dentry * old_dentry,
+ struct inode * dir, struct dentry *dentry)
+{
+ handle_t *handle;
+ struct inode *inode = old_dentry->d_inode;
+ int err, retries = 0;
+
+ if (inode->i_nlink >= EXT4_LINK_MAX)
+ return -EMLINK;
+
+retry:
+ handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+ EXT4_INDEX_EXTRA_TRANS_BLOCKS);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ if (IS_DIRSYNC(dir))
+ handle->h_sync = 1;
+
+ inode->i_ctime = CURRENT_TIME_SEC;
+ ext4_inc_count(handle, inode);
+ atomic_inc(&inode->i_count);
+
+ err = ext4_add_nondir(handle, dentry, inode);
+ ext4_journal_stop(handle);
+ if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
+ goto retry;
+ return err;
+}
+
+#define PARENT_INO(buffer) \
+ ((struct ext4_dir_entry_2 *) ((char *) buffer + \
+ le16_to_cpu(((struct ext4_dir_entry_2 *) buffer)->rec_len)))->inode
+
+/*
+ * Anybody can rename anything with this: the permission checks are left to the
+ * higher-level routines.
+ */
+static int ext4_rename (struct inode * old_dir, struct dentry *old_dentry,
+ struct inode * new_dir,struct dentry *new_dentry)
+{
+ handle_t *handle;
+ struct inode * old_inode, * new_inode;
+ struct buffer_head * old_bh, * new_bh, * dir_bh;
+ struct ext4_dir_entry_2 * old_de, * new_de;
+ int retval;
+
+ old_bh = new_bh = dir_bh = NULL;
+
+ /* Initialize quotas before so that eventual writes go
+ * in separate transaction */
+ if (new_dentry->d_inode)
+ DQUOT_INIT(new_dentry->d_inode);
+ handle = ext4_journal_start(old_dir, 2 *
+ EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
+ EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
+ handle->h_sync = 1;
+
+ old_bh = ext4_find_entry (old_dentry, &old_de);
+ /*
+ * Check for inode number is _not_ due to possible IO errors.
+ * We might rmdir the source, keep it as pwd of some process
+ * and merrily kill the link to whatever was created under the
+ * same name. Goodbye sticky bit ;-<
+ */
+ old_inode = old_dentry->d_inode;
+ retval = -ENOENT;
+ if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
+ goto end_rename;
+
+ new_inode = new_dentry->d_inode;
+ new_bh = ext4_find_entry (new_dentry, &new_de);
+ if (new_bh) {
+ if (!new_inode) {
+ brelse (new_bh);
+ new_bh = NULL;
+ }
+ }
+ if (S_ISDIR(old_inode->i_mode)) {
+ if (new_inode) {
+ retval = -ENOTEMPTY;
+ if (!empty_dir (new_inode))
+ goto end_rename;
+ }
+ retval = -EIO;
+ dir_bh = ext4_bread (handle, old_inode, 0, 0, &retval);
+ if (!dir_bh)
+ goto end_rename;
+ if (le32_to_cpu(PARENT_INO(dir_bh->b_data)) != old_dir->i_ino)
+ goto end_rename;
+ retval = -EMLINK;
+ if (!new_inode && new_dir!=old_dir &&
+ new_dir->i_nlink >= EXT4_LINK_MAX)
+ goto end_rename;
+ }
+ if (!new_bh) {
+ retval = ext4_add_entry (handle, new_dentry, old_inode);
+ if (retval)
+ goto end_rename;
+ } else {
+ BUFFER_TRACE(new_bh, "get write access");
+ ext4_journal_get_write_access(handle, new_bh);
+ new_de->inode = cpu_to_le32(old_inode->i_ino);
+ if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
+ EXT4_FEATURE_INCOMPAT_FILETYPE))
+ new_de->file_type = old_de->file_type;
+ new_dir->i_version++;
+ BUFFER_TRACE(new_bh, "call ext4_journal_dirty_metadata");
+ ext4_journal_dirty_metadata(handle, new_bh);
+ brelse(new_bh);
+ new_bh = NULL;
+ }
+
+ /*
+ * Like most other Unix systems, set the ctime for inodes on a
+ * rename.
+ */
+ old_inode->i_ctime = CURRENT_TIME_SEC;
+ ext4_mark_inode_dirty(handle, old_inode);
+
+ /*
+ * ok, that's it
+ */
+ if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
+ old_de->name_len != old_dentry->d_name.len ||
+ strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
+ (retval = ext4_delete_entry(handle, old_dir,
+ old_de, old_bh)) == -ENOENT) {
+ /* old_de could have moved from under us during htree split, so
+ * make sure that we are deleting the right entry. We might
+ * also be pointing to a stale entry in the unused part of
+ * old_bh so just checking inum and the name isn't enough. */
+ struct buffer_head *old_bh2;
+ struct ext4_dir_entry_2 *old_de2;
+
+ old_bh2 = ext4_find_entry(old_dentry, &old_de2);
+ if (old_bh2) {
+ retval = ext4_delete_entry(handle, old_dir,
+ old_de2, old_bh2);
+ brelse(old_bh2);
+ }
+ }
+ if (retval) {
+ ext4_warning(old_dir->i_sb, "ext4_rename",
+ "Deleting old file (%lu), %d, error=%d",
+ old_dir->i_ino, old_dir->i_nlink, retval);
+ }
+
+ if (new_inode) {
+ drop_nlink(new_inode);
+ new_inode->i_ctime = CURRENT_TIME_SEC;
+ }
+ old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
+ ext4_update_dx_flag(old_dir);
+ if (dir_bh) {
+ BUFFER_TRACE(dir_bh, "get_write_access");
+ ext4_journal_get_write_access(handle, dir_bh);
+ PARENT_INO(dir_bh->b_data) = cpu_to_le32(new_dir->i_ino);
+ BUFFER_TRACE(dir_bh, "call ext4_journal_dirty_metadata");
+ ext4_journal_dirty_metadata(handle, dir_bh);
+ drop_nlink(old_dir);
+ if (new_inode) {
+ drop_nlink(new_inode);
+ } else {
+ inc_nlink(new_dir);
+ ext4_update_dx_flag(new_dir);
+ ext4_mark_inode_dirty(handle, new_dir);
+ }
+ }
+ ext4_mark_inode_dirty(handle, old_dir);
+ if (new_inode) {
+ ext4_mark_inode_dirty(handle, new_inode);
+ if (!new_inode->i_nlink)
+ ext4_orphan_add(handle, new_inode);
+ }
+ retval = 0;
+
+end_rename:
+ brelse (dir_bh);
+ brelse (old_bh);
+ brelse (new_bh);
+ ext4_journal_stop(handle);
+ return retval;
+}
+
+/*
+ * directories can handle most operations...
+ */
+struct inode_operations ext4_dir_inode_operations = {
+ .create = ext4_create,
+ .lookup = ext4_lookup,
+ .link = ext4_link,
+ .unlink = ext4_unlink,
+ .symlink = ext4_symlink,
+ .mkdir = ext4_mkdir,
+ .rmdir = ext4_rmdir,
+ .mknod = ext4_mknod,
+ .rename = ext4_rename,
+ .setattr = ext4_setattr,
+#ifdef CONFIG_EXT4DEV_FS_XATTR
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
+ .listxattr = ext4_listxattr,
+ .removexattr = generic_removexattr,
+#endif
+ .permission = ext4_permission,
+ .sync_flags = ext4_sync_flags,
+};
+
+struct inode_operations ext4_special_inode_operations = {
+ .setattr = ext4_setattr,
+#ifdef CONFIG_EXT4DEV_FS_XATTR
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
+ .listxattr = ext4_listxattr,
+ .removexattr = generic_removexattr,
+#endif
+ .permission = ext4_permission,
+ .sync_flags = ext4_sync_flags,
+};
git://git.onelab.eu / linux-2.6.git / blobdiff