[readdir] convert ext3
new helper: dir_relax(inode). Call when you are in location that will _not_ be invalidated by directory modifications (block boundary, in case of ext*). Returns whether the directory has survived (dropping i_mutex allows rmdir to kill the sucker; if it returns false to us, ->iterate() is obviously done) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
parent
5f99f4e79a
commit
5ded75ec4c
2 changed files with 70 additions and 93 deletions
157
fs/ext3/dir.c
157
fs/ext3/dir.c
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@ -28,8 +28,7 @@ static unsigned char ext3_filetype_table[] = {
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DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
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};
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static int ext3_dx_readdir(struct file * filp,
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void * dirent, filldir_t filldir);
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static int ext3_dx_readdir(struct file *, struct dir_context *);
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static unsigned char get_dtype(struct super_block *sb, int filetype)
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{
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@ -91,36 +90,30 @@ int ext3_check_dir_entry (const char * function, struct inode * dir,
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return error_msg == NULL ? 1 : 0;
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}
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static int ext3_readdir(struct file * filp,
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void * dirent, filldir_t filldir)
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static int ext3_readdir(struct file *file, struct dir_context *ctx)
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{
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int error = 0;
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unsigned long offset;
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int i, stored;
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int i;
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struct ext3_dir_entry_2 *de;
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int err;
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struct inode *inode = file_inode(filp);
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struct inode *inode = file_inode(file);
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struct super_block *sb = inode->i_sb;
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int ret = 0;
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int dir_has_error = 0;
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if (is_dx_dir(inode)) {
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err = ext3_dx_readdir(filp, dirent, filldir);
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if (err != ERR_BAD_DX_DIR) {
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ret = err;
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goto out;
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}
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err = ext3_dx_readdir(file, ctx);
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if (err != ERR_BAD_DX_DIR)
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return err;
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/*
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* We don't set the inode dirty flag since it's not
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* critical that it get flushed back to the disk.
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*/
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EXT3_I(file_inode(filp))->i_flags &= ~EXT3_INDEX_FL;
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EXT3_I(inode)->i_flags &= ~EXT3_INDEX_FL;
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}
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stored = 0;
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offset = filp->f_pos & (sb->s_blocksize - 1);
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offset = ctx->pos & (sb->s_blocksize - 1);
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while (!error && !stored && filp->f_pos < inode->i_size) {
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unsigned long blk = filp->f_pos >> EXT3_BLOCK_SIZE_BITS(sb);
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while (ctx->pos < inode->i_size) {
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unsigned long blk = ctx->pos >> EXT3_BLOCK_SIZE_BITS(sb);
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struct buffer_head map_bh;
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struct buffer_head *bh = NULL;
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@ -129,12 +122,12 @@ static int ext3_readdir(struct file * filp,
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if (err > 0) {
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pgoff_t index = map_bh.b_blocknr >>
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(PAGE_CACHE_SHIFT - inode->i_blkbits);
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if (!ra_has_index(&filp->f_ra, index))
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if (!ra_has_index(&file->f_ra, index))
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page_cache_sync_readahead(
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sb->s_bdev->bd_inode->i_mapping,
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&filp->f_ra, filp,
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&file->f_ra, file,
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index, 1);
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filp->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
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file->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
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bh = ext3_bread(NULL, inode, blk, 0, &err);
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}
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@ -146,22 +139,21 @@ static int ext3_readdir(struct file * filp,
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if (!dir_has_error) {
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ext3_error(sb, __func__, "directory #%lu "
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"contains a hole at offset %lld",
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inode->i_ino, filp->f_pos);
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inode->i_ino, ctx->pos);
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dir_has_error = 1;
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}
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/* corrupt size? Maybe no more blocks to read */
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if (filp->f_pos > inode->i_blocks << 9)
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if (ctx->pos > inode->i_blocks << 9)
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break;
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filp->f_pos += sb->s_blocksize - offset;
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ctx->pos += sb->s_blocksize - offset;
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continue;
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}
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revalidate:
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/* If the dir block has changed since the last call to
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* readdir(2), then we might be pointing to an invalid
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* dirent right now. Scan from the start of the block
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* to make sure. */
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if (filp->f_version != inode->i_version) {
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if (offset && file->f_version != inode->i_version) {
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for (i = 0; i < sb->s_blocksize && i < offset; ) {
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de = (struct ext3_dir_entry_2 *)
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(bh->b_data + i);
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@ -177,53 +169,40 @@ static int ext3_readdir(struct file * filp,
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i += ext3_rec_len_from_disk(de->rec_len);
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}
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offset = i;
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filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
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ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1))
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| offset;
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filp->f_version = inode->i_version;
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file->f_version = inode->i_version;
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}
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while (!error && filp->f_pos < inode->i_size
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while (ctx->pos < inode->i_size
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&& offset < sb->s_blocksize) {
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de = (struct ext3_dir_entry_2 *) (bh->b_data + offset);
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if (!ext3_check_dir_entry ("ext3_readdir", inode, de,
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bh, offset)) {
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/* On error, skip the f_pos to the
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/* On error, skip the to the
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next block. */
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filp->f_pos = (filp->f_pos |
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ctx->pos = (ctx->pos |
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(sb->s_blocksize - 1)) + 1;
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brelse (bh);
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ret = stored;
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goto out;
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break;
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}
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offset += ext3_rec_len_from_disk(de->rec_len);
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if (le32_to_cpu(de->inode)) {
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/* We might block in the next section
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* if the data destination is
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* currently swapped out. So, use a
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* version stamp to detect whether or
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* not the directory has been modified
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* during the copy operation.
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*/
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u64 version = filp->f_version;
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error = filldir(dirent, de->name,
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de->name_len,
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filp->f_pos,
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le32_to_cpu(de->inode),
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get_dtype(sb, de->file_type));
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if (error)
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break;
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if (version != filp->f_version)
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goto revalidate;
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stored ++;
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if (!dir_emit(ctx, de->name, de->name_len,
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le32_to_cpu(de->inode),
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get_dtype(sb, de->file_type))) {
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brelse(bh);
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return 0;
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}
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}
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filp->f_pos += ext3_rec_len_from_disk(de->rec_len);
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ctx->pos += ext3_rec_len_from_disk(de->rec_len);
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}
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offset = 0;
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brelse (bh);
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if (ctx->pos < inode->i_size)
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if (!dir_relax(inode))
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return 0;
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}
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out:
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return ret;
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return 0;
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}
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static inline int is_32bit_api(void)
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@ -452,62 +431,54 @@ int ext3_htree_store_dirent(struct file *dir_file, __u32 hash,
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* for all entres on the fname linked list. (Normally there is only
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* one entry on the linked list, unless there are 62 bit hash collisions.)
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*/
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static int call_filldir(struct file * filp, void * dirent,
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filldir_t filldir, struct fname *fname)
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static bool call_filldir(struct file *file, struct dir_context *ctx,
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struct fname *fname)
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{
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struct dir_private_info *info = filp->private_data;
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loff_t curr_pos;
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struct inode *inode = file_inode(filp);
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struct super_block * sb;
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int error;
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sb = inode->i_sb;
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struct dir_private_info *info = file->private_data;
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struct inode *inode = file_inode(file);
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struct super_block *sb = inode->i_sb;
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if (!fname) {
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printk("call_filldir: called with null fname?!?\n");
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return 0;
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return true;
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}
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curr_pos = hash2pos(filp, fname->hash, fname->minor_hash);
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ctx->pos = hash2pos(file, fname->hash, fname->minor_hash);
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while (fname) {
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error = filldir(dirent, fname->name,
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fname->name_len, curr_pos,
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if (!dir_emit(ctx, fname->name, fname->name_len,
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fname->inode,
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get_dtype(sb, fname->file_type));
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if (error) {
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filp->f_pos = curr_pos;
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get_dtype(sb, fname->file_type))) {
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info->extra_fname = fname;
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return error;
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return false;
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}
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fname = fname->next;
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}
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return 0;
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return true;
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}
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static int ext3_dx_readdir(struct file * filp,
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void * dirent, filldir_t filldir)
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static int ext3_dx_readdir(struct file *file, struct dir_context *ctx)
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{
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struct dir_private_info *info = filp->private_data;
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struct inode *inode = file_inode(filp);
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struct dir_private_info *info = file->private_data;
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struct inode *inode = file_inode(file);
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struct fname *fname;
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int ret;
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if (!info) {
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info = ext3_htree_create_dir_info(filp, filp->f_pos);
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info = ext3_htree_create_dir_info(file, ctx->pos);
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if (!info)
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return -ENOMEM;
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filp->private_data = info;
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file->private_data = info;
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}
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if (filp->f_pos == ext3_get_htree_eof(filp))
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if (ctx->pos == ext3_get_htree_eof(file))
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return 0; /* EOF */
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/* Some one has messed with f_pos; reset the world */
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if (info->last_pos != filp->f_pos) {
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if (info->last_pos != ctx->pos) {
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free_rb_tree_fname(&info->root);
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info->curr_node = NULL;
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info->extra_fname = NULL;
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info->curr_hash = pos2maj_hash(filp, filp->f_pos);
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info->curr_minor_hash = pos2min_hash(filp, filp->f_pos);
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info->curr_hash = pos2maj_hash(file, ctx->pos);
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info->curr_minor_hash = pos2min_hash(file, ctx->pos);
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}
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/*
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@ -515,7 +486,7 @@ static int ext3_dx_readdir(struct file * filp,
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* chain, return them first.
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*/
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if (info->extra_fname) {
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if (call_filldir(filp, dirent, filldir, info->extra_fname))
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if (!call_filldir(file, ctx, info->extra_fname))
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goto finished;
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info->extra_fname = NULL;
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goto next_node;
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@ -529,17 +500,17 @@ static int ext3_dx_readdir(struct file * filp,
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* cached entries.
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*/
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if ((!info->curr_node) ||
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(filp->f_version != inode->i_version)) {
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(file->f_version != inode->i_version)) {
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info->curr_node = NULL;
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free_rb_tree_fname(&info->root);
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filp->f_version = inode->i_version;
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ret = ext3_htree_fill_tree(filp, info->curr_hash,
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file->f_version = inode->i_version;
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ret = ext3_htree_fill_tree(file, info->curr_hash,
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info->curr_minor_hash,
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&info->next_hash);
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if (ret < 0)
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return ret;
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if (ret == 0) {
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filp->f_pos = ext3_get_htree_eof(filp);
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ctx->pos = ext3_get_htree_eof(file);
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break;
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}
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info->curr_node = rb_first(&info->root);
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@ -548,7 +519,7 @@ static int ext3_dx_readdir(struct file * filp,
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fname = rb_entry(info->curr_node, struct fname, rb_hash);
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info->curr_hash = fname->hash;
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info->curr_minor_hash = fname->minor_hash;
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if (call_filldir(filp, dirent, filldir, fname))
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if (!call_filldir(file, ctx, fname))
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break;
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next_node:
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info->curr_node = rb_next(info->curr_node);
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@ -559,7 +530,7 @@ static int ext3_dx_readdir(struct file * filp,
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info->curr_minor_hash = fname->minor_hash;
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} else {
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if (info->next_hash == ~0) {
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filp->f_pos = ext3_get_htree_eof(filp);
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ctx->pos = ext3_get_htree_eof(file);
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break;
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}
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info->curr_hash = info->next_hash;
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@ -567,7 +538,7 @@ static int ext3_dx_readdir(struct file * filp,
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}
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}
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finished:
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info->last_pos = filp->f_pos;
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info->last_pos = ctx->pos;
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return 0;
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}
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@ -582,7 +553,7 @@ static int ext3_release_dir (struct inode * inode, struct file * filp)
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const struct file_operations ext3_dir_operations = {
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.llseek = ext3_dir_llseek,
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.read = generic_read_dir,
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.readdir = ext3_readdir,
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.iterate = ext3_readdir,
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.unlocked_ioctl = ext3_ioctl,
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#ifdef CONFIG_COMPAT
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.compat_ioctl = ext3_compat_ioctl,
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@ -2725,5 +2725,11 @@ static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx)
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}
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return true;
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}
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static inline bool dir_relax(struct inode *inode)
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{
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mutex_unlock(&inode->i_mutex);
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mutex_lock(&inode->i_mutex);
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return !IS_DEADDIR(inode);
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}
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#endif /* _LINUX_FS_H */
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