diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/ext4/dir.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/ext4/dir.c | 667 |
1 files changed, 0 insertions, 667 deletions
diff --git a/ANDROID_3.4.5/fs/ext4/dir.c b/ANDROID_3.4.5/fs/ext4/dir.c deleted file mode 100644 index b8678620..00000000 --- a/ANDROID_3.4.5/fs/ext4/dir.c +++ /dev/null @@ -1,667 +0,0 @@ -/* - * linux/fs/ext4/dir.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/dir.c - * - * Copyright (C) 1991, 1992 Linus Torvalds - * - * ext4 directory handling functions - * - * Big-endian to little-endian byte-swapping/bitmaps by - * David S. Miller (davem@caip.rutgers.edu), 1995 - * - * Hash Tree Directory indexing (c) 2001 Daniel Phillips - * - */ - -#include <linux/fs.h> -#include <linux/jbd2.h> -#include <linux/buffer_head.h> -#include <linux/slab.h> -#include <linux/rbtree.h> -#include "ext4.h" - -static unsigned char ext4_filetype_table[] = { - DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK -}; - -static int ext4_dx_readdir(struct file *filp, - void *dirent, filldir_t filldir); - -static unsigned char get_dtype(struct super_block *sb, int filetype) -{ - if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) || - (filetype >= EXT4_FT_MAX)) - return DT_UNKNOWN; - - return (ext4_filetype_table[filetype]); -} - -/** - * Check if the given dir-inode refers to an htree-indexed directory - * (or a directory which chould potentially get coverted to use htree - * indexing). - * - * Return 1 if it is a dx dir, 0 if not - */ -static int is_dx_dir(struct inode *inode) -{ - struct super_block *sb = inode->i_sb; - - if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb, - EXT4_FEATURE_COMPAT_DIR_INDEX) && - ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) || - ((inode->i_size >> sb->s_blocksize_bits) == 1))) - return 1; - - return 0; -} - -/* - * Return 0 if the directory entry is OK, and 1 if there is a problem - * - * Note: this is the opposite of what ext2 and ext3 historically returned... - */ -int __ext4_check_dir_entry(const char *function, unsigned int line, - struct inode *dir, struct file *filp, - struct ext4_dir_entry_2 *de, - struct buffer_head *bh, - unsigned int offset) -{ - const char *error_msg = NULL; - const int rlen = ext4_rec_len_from_disk(de->rec_len, - dir->i_sb->s_blocksize); - - if (unlikely(rlen < EXT4_DIR_REC_LEN(1))) - error_msg = "rec_len is smaller than minimal"; - else if (unlikely(rlen % 4 != 0)) - error_msg = "rec_len % 4 != 0"; - else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len))) - error_msg = "rec_len is too small for name_len"; - else if (unlikely(((char *) de - bh->b_data) + rlen > - dir->i_sb->s_blocksize)) - error_msg = "directory entry across blocks"; - else if (unlikely(le32_to_cpu(de->inode) > - le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))) - error_msg = "inode out of bounds"; - else - return 0; - - if (filp) - ext4_error_file(filp, function, line, bh->b_blocknr, - "bad entry in directory: %s - offset=%u(%u), " - "inode=%u, rec_len=%d, name_len=%d", - error_msg, (unsigned) (offset % bh->b_size), - offset, le32_to_cpu(de->inode), - rlen, de->name_len); - else - ext4_error_inode(dir, function, line, bh->b_blocknr, - "bad entry in directory: %s - offset=%u(%u), " - "inode=%u, rec_len=%d, name_len=%d", - error_msg, (unsigned) (offset % bh->b_size), - offset, le32_to_cpu(de->inode), - rlen, de->name_len); - - return 1; -} - -static int ext4_readdir(struct file *filp, - void *dirent, filldir_t filldir) -{ - int error = 0; - unsigned int offset; - int i, stored; - struct ext4_dir_entry_2 *de; - int err; - struct inode *inode = filp->f_path.dentry->d_inode; - struct super_block *sb = inode->i_sb; - int ret = 0; - int dir_has_error = 0; - - if (is_dx_dir(inode)) { - err = ext4_dx_readdir(filp, dirent, filldir); - if (err != ERR_BAD_DX_DIR) { - ret = err; - goto out; - } - /* - * We don't set the inode dirty flag since it's not - * critical that it get flushed back to the disk. - */ - ext4_clear_inode_flag(filp->f_path.dentry->d_inode, - EXT4_INODE_INDEX); - } - stored = 0; - offset = filp->f_pos & (sb->s_blocksize - 1); - - while (!error && !stored && filp->f_pos < inode->i_size) { - struct ext4_map_blocks map; - struct buffer_head *bh = NULL; - - map.m_lblk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb); - map.m_len = 1; - err = ext4_map_blocks(NULL, inode, &map, 0); - if (err > 0) { - pgoff_t index = map.m_pblk >> - (PAGE_CACHE_SHIFT - inode->i_blkbits); - if (!ra_has_index(&filp->f_ra, index)) - page_cache_sync_readahead( - sb->s_bdev->bd_inode->i_mapping, - &filp->f_ra, filp, - index, 1); - filp->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT; - bh = ext4_bread(NULL, inode, map.m_lblk, 0, &err); - } - - /* - * We ignore I/O errors on directories so users have a chance - * of recovering data when there's a bad sector - */ - if (!bh) { - if (!dir_has_error) { - EXT4_ERROR_FILE(filp, 0, - "directory contains a " - "hole at offset %llu", - (unsigned long long) filp->f_pos); - dir_has_error = 1; - } - /* corrupt size? Maybe no more blocks to read */ - if (filp->f_pos > inode->i_blocks << 9) - break; - filp->f_pos += sb->s_blocksize - offset; - continue; - } - -revalidate: - /* If the dir block has changed since the last call to - * readdir(2), then we might be pointing to an invalid - * dirent right now. Scan from the start of the block - * to make sure. */ - if (filp->f_version != inode->i_version) { - for (i = 0; i < sb->s_blocksize && i < offset; ) { - de = (struct ext4_dir_entry_2 *) - (bh->b_data + i); - /* It's too expensive to do a full - * dirent test each time round this - * loop, but we do have to test at - * least that it is non-zero. A - * failure will be detected in the - * dirent test below. */ - if (ext4_rec_len_from_disk(de->rec_len, - sb->s_blocksize) < EXT4_DIR_REC_LEN(1)) - break; - i += ext4_rec_len_from_disk(de->rec_len, - sb->s_blocksize); - } - offset = i; - filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1)) - | offset; - filp->f_version = inode->i_version; - } - - while (!error && filp->f_pos < inode->i_size - && offset < sb->s_blocksize) { - de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); - if (ext4_check_dir_entry(inode, filp, de, - bh, offset)) { - /* - * On error, skip the f_pos to the next block - */ - filp->f_pos = (filp->f_pos | - (sb->s_blocksize - 1)) + 1; - brelse(bh); - ret = stored; - goto out; - } - offset += ext4_rec_len_from_disk(de->rec_len, - sb->s_blocksize); - if (le32_to_cpu(de->inode)) { - /* We might block in the next section - * if the data destination is - * currently swapped out. So, use a - * version stamp to detect whether or - * not the directory has been modified - * during the copy operation. - */ - u64 version = filp->f_version; - - error = filldir(dirent, de->name, - de->name_len, - filp->f_pos, - le32_to_cpu(de->inode), - get_dtype(sb, de->file_type)); - if (error) - break; - if (version != filp->f_version) - goto revalidate; - stored++; - } - filp->f_pos += ext4_rec_len_from_disk(de->rec_len, - sb->s_blocksize); - } - offset = 0; - brelse(bh); - } -out: - return ret; -} - -static inline int is_32bit_api(void) -{ -#ifdef CONFIG_COMPAT - return is_compat_task(); -#else - return (BITS_PER_LONG == 32); -#endif -} - -/* - * These functions convert from the major/minor hash to an f_pos - * value for dx directories - * - * Upper layer (for example NFS) should specify FMODE_32BITHASH or - * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted - * directly on both 32-bit and 64-bit nodes, under such case, neither - * FMODE_32BITHASH nor FMODE_64BITHASH is specified. - */ -static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor) -{ - if ((filp->f_mode & FMODE_32BITHASH) || - (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) - return major >> 1; - else - return ((__u64)(major >> 1) << 32) | (__u64)minor; -} - -static inline __u32 pos2maj_hash(struct file *filp, loff_t pos) -{ - if ((filp->f_mode & FMODE_32BITHASH) || - (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) - return (pos << 1) & 0xffffffff; - else - return ((pos >> 32) << 1) & 0xffffffff; -} - -static inline __u32 pos2min_hash(struct file *filp, loff_t pos) -{ - if ((filp->f_mode & FMODE_32BITHASH) || - (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) - return 0; - else - return pos & 0xffffffff; -} - -/* - * Return 32- or 64-bit end-of-file for dx directories - */ -static inline loff_t ext4_get_htree_eof(struct file *filp) -{ - if ((filp->f_mode & FMODE_32BITHASH) || - (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) - return EXT4_HTREE_EOF_32BIT; - else - return EXT4_HTREE_EOF_64BIT; -} - - -/* - * ext4_dir_llseek() based on generic_file_llseek() to handle both - * non-htree and htree directories, where the "offset" is in terms - * of the filename hash value instead of the byte offset. - * - * NOTE: offsets obtained *before* ext4_set_inode_flag(dir, EXT4_INODE_INDEX) - * will be invalid once the directory was converted into a dx directory - */ -loff_t ext4_dir_llseek(struct file *file, loff_t offset, int origin) -{ - struct inode *inode = file->f_mapping->host; - loff_t ret = -EINVAL; - int dx_dir = is_dx_dir(inode); - - mutex_lock(&inode->i_mutex); - - /* NOTE: relative offsets with dx directories might not work - * as expected, as it is difficult to figure out the - * correct offset between dx hashes */ - - switch (origin) { - case SEEK_END: - if (unlikely(offset > 0)) - goto out_err; /* not supported for directories */ - - /* so only negative offsets are left, does that have a - * meaning for directories at all? */ - if (dx_dir) - offset += ext4_get_htree_eof(file); - else - offset += inode->i_size; - break; - case SEEK_CUR: - /* - * Here we special-case the lseek(fd, 0, SEEK_CUR) - * position-querying operation. Avoid rewriting the "same" - * f_pos value back to the file because a concurrent read(), - * write() or lseek() might have altered it - */ - if (offset == 0) { - offset = file->f_pos; - goto out_ok; - } - - offset += file->f_pos; - break; - } - - if (unlikely(offset < 0)) - goto out_err; - - if (!dx_dir) { - if (offset > inode->i_sb->s_maxbytes) - goto out_err; - } else if (offset > ext4_get_htree_eof(file)) - goto out_err; - - /* Special lock needed here? */ - if (offset != file->f_pos) { - file->f_pos = offset; - file->f_version = 0; - } - -out_ok: - ret = offset; -out_err: - mutex_unlock(&inode->i_mutex); - - return ret; -} - -/* - * This structure holds the nodes of the red-black tree used to store - * the directory entry in hash order. - */ -struct fname { - __u32 hash; - __u32 minor_hash; - struct rb_node rb_hash; - struct fname *next; - __u32 inode; - __u8 name_len; - __u8 file_type; - char name[0]; -}; - -/* - * This functoin implements a non-recursive way of freeing all of the - * nodes in the red-black tree. - */ -static void free_rb_tree_fname(struct rb_root *root) -{ - struct rb_node *n = root->rb_node; - struct rb_node *parent; - struct fname *fname; - - while (n) { - /* Do the node's children first */ - if (n->rb_left) { - n = n->rb_left; - continue; - } - if (n->rb_right) { - n = n->rb_right; - continue; - } - /* - * The node has no children; free it, and then zero - * out parent's link to it. Finally go to the - * beginning of the loop and try to free the parent - * node. - */ - parent = rb_parent(n); - fname = rb_entry(n, struct fname, rb_hash); - while (fname) { - struct fname *old = fname; - fname = fname->next; - kfree(old); - } - if (!parent) - *root = RB_ROOT; - else if (parent->rb_left == n) - parent->rb_left = NULL; - else if (parent->rb_right == n) - parent->rb_right = NULL; - n = parent; - } -} - - -static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp, - loff_t pos) -{ - struct dir_private_info *p; - - p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL); - if (!p) - return NULL; - p->curr_hash = pos2maj_hash(filp, pos); - p->curr_minor_hash = pos2min_hash(filp, pos); - return p; -} - -void ext4_htree_free_dir_info(struct dir_private_info *p) -{ - free_rb_tree_fname(&p->root); - kfree(p); -} - -/* - * Given a directory entry, enter it into the fname rb tree. - */ -int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, - __u32 minor_hash, - struct ext4_dir_entry_2 *dirent) -{ - struct rb_node **p, *parent = NULL; - struct fname *fname, *new_fn; - struct dir_private_info *info; - int len; - - info = dir_file->private_data; - p = &info->root.rb_node; - - /* Create and allocate the fname structure */ - len = sizeof(struct fname) + dirent->name_len + 1; - new_fn = kzalloc(len, GFP_KERNEL); - if (!new_fn) - return -ENOMEM; - new_fn->hash = hash; - new_fn->minor_hash = minor_hash; - new_fn->inode = le32_to_cpu(dirent->inode); - new_fn->name_len = dirent->name_len; - new_fn->file_type = dirent->file_type; - memcpy(new_fn->name, dirent->name, dirent->name_len); - new_fn->name[dirent->name_len] = 0; - - while (*p) { - parent = *p; - fname = rb_entry(parent, struct fname, rb_hash); - - /* - * If the hash and minor hash match up, then we put - * them on a linked list. This rarely happens... - */ - if ((new_fn->hash == fname->hash) && - (new_fn->minor_hash == fname->minor_hash)) { - new_fn->next = fname->next; - fname->next = new_fn; - return 0; - } - - if (new_fn->hash < fname->hash) - p = &(*p)->rb_left; - else if (new_fn->hash > fname->hash) - p = &(*p)->rb_right; - else if (new_fn->minor_hash < fname->minor_hash) - p = &(*p)->rb_left; - else /* if (new_fn->minor_hash > fname->minor_hash) */ - p = &(*p)->rb_right; - } - - rb_link_node(&new_fn->rb_hash, parent, p); - rb_insert_color(&new_fn->rb_hash, &info->root); - return 0; -} - - - -/* - * This is a helper function for ext4_dx_readdir. It calls filldir - * for all entres on the fname linked list. (Normally there is only - * one entry on the linked list, unless there are 62 bit hash collisions.) - */ -static int call_filldir(struct file *filp, void *dirent, - filldir_t filldir, struct fname *fname) -{ - struct dir_private_info *info = filp->private_data; - loff_t curr_pos; - struct inode *inode = filp->f_path.dentry->d_inode; - struct super_block *sb; - int error; - - sb = inode->i_sb; - - if (!fname) { - ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: " - "called with null fname?!?", __func__, __LINE__, - inode->i_ino, current->comm); - return 0; - } - curr_pos = hash2pos(filp, fname->hash, fname->minor_hash); - while (fname) { - error = filldir(dirent, fname->name, - fname->name_len, curr_pos, - fname->inode, - get_dtype(sb, fname->file_type)); - if (error) { - filp->f_pos = curr_pos; - info->extra_fname = fname; - return error; - } - fname = fname->next; - } - return 0; -} - -static int ext4_dx_readdir(struct file *filp, - void *dirent, filldir_t filldir) -{ - struct dir_private_info *info = filp->private_data; - struct inode *inode = filp->f_path.dentry->d_inode; - struct fname *fname; - int ret; - - if (!info) { - info = ext4_htree_create_dir_info(filp, filp->f_pos); - if (!info) - return -ENOMEM; - filp->private_data = info; - } - - if (filp->f_pos == ext4_get_htree_eof(filp)) - return 0; /* EOF */ - - /* Some one has messed with f_pos; reset the world */ - if (info->last_pos != filp->f_pos) { - free_rb_tree_fname(&info->root); - info->curr_node = NULL; - info->extra_fname = NULL; - info->curr_hash = pos2maj_hash(filp, filp->f_pos); - info->curr_minor_hash = pos2min_hash(filp, filp->f_pos); - } - - /* - * If there are any leftover names on the hash collision - * chain, return them first. - */ - if (info->extra_fname) { - if (call_filldir(filp, dirent, filldir, info->extra_fname)) - goto finished; - info->extra_fname = NULL; - goto next_node; - } else if (!info->curr_node) - info->curr_node = rb_first(&info->root); - - while (1) { - /* - * Fill the rbtree if we have no more entries, - * or the inode has changed since we last read in the - * cached entries. - */ - if ((!info->curr_node) || - (filp->f_version != inode->i_version)) { - info->curr_node = NULL; - free_rb_tree_fname(&info->root); - filp->f_version = inode->i_version; - ret = ext4_htree_fill_tree(filp, info->curr_hash, - info->curr_minor_hash, - &info->next_hash); - if (ret < 0) - return ret; - if (ret == 0) { - filp->f_pos = ext4_get_htree_eof(filp); - break; - } - info->curr_node = rb_first(&info->root); - } - - fname = rb_entry(info->curr_node, struct fname, rb_hash); - info->curr_hash = fname->hash; - info->curr_minor_hash = fname->minor_hash; - if (call_filldir(filp, dirent, filldir, fname)) - break; - next_node: - info->curr_node = rb_next(info->curr_node); - if (info->curr_node) { - fname = rb_entry(info->curr_node, struct fname, - rb_hash); - info->curr_hash = fname->hash; - info->curr_minor_hash = fname->minor_hash; - } else { - if (info->next_hash == ~0) { - filp->f_pos = ext4_get_htree_eof(filp); - break; - } - info->curr_hash = info->next_hash; - info->curr_minor_hash = 0; - } - } -finished: - info->last_pos = filp->f_pos; - return 0; -} - -static int ext4_release_dir(struct inode *inode, struct file *filp) -{ - if (filp->private_data) - ext4_htree_free_dir_info(filp->private_data); - - return 0; -} - -const struct file_operations ext4_dir_operations = { - .llseek = ext4_dir_llseek, - .read = generic_read_dir, - .readdir = ext4_readdir, - .unlocked_ioctl = ext4_ioctl, -#ifdef CONFIG_COMPAT - .compat_ioctl = ext4_compat_ioctl, -#endif - .fsync = ext4_sync_file, - .release = ext4_release_dir, -}; |