From 5ded75ec4c576577cae7d556e671d11d0c80c2fc Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 15 May 2013 21:02:48 -0400 Subject: [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 --- fs/ext3/dir.c | 157 ++++++++++++++++++++++++---------------------------------- 1 file changed, 64 insertions(+), 93 deletions(-) (limited to 'fs/ext3') diff --git a/fs/ext3/dir.c b/fs/ext3/dir.c index 87eccbbca255..f522425aaa24 100644 --- a/fs/ext3/dir.c +++ b/fs/ext3/dir.c @@ -28,8 +28,7 @@ static unsigned char ext3_filetype_table[] = { DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK }; -static int ext3_dx_readdir(struct file * filp, - void * dirent, filldir_t filldir); +static int ext3_dx_readdir(struct file *, struct dir_context *); static unsigned char get_dtype(struct super_block *sb, int filetype) { @@ -91,36 +90,30 @@ int ext3_check_dir_entry (const char * function, struct inode * dir, return error_msg == NULL ? 1 : 0; } -static int ext3_readdir(struct file * filp, - void * dirent, filldir_t filldir) +static int ext3_readdir(struct file *file, struct dir_context *ctx) { - int error = 0; unsigned long offset; - int i, stored; + int i; struct ext3_dir_entry_2 *de; int err; - struct inode *inode = file_inode(filp); + struct inode *inode = file_inode(file); struct super_block *sb = inode->i_sb; - int ret = 0; int dir_has_error = 0; if (is_dx_dir(inode)) { - err = ext3_dx_readdir(filp, dirent, filldir); - if (err != ERR_BAD_DX_DIR) { - ret = err; - goto out; - } + err = ext3_dx_readdir(file, ctx); + if (err != ERR_BAD_DX_DIR) + return err; /* * We don't set the inode dirty flag since it's not * critical that it get flushed back to the disk. */ - EXT3_I(file_inode(filp))->i_flags &= ~EXT3_INDEX_FL; + EXT3_I(inode)->i_flags &= ~EXT3_INDEX_FL; } - stored = 0; - offset = filp->f_pos & (sb->s_blocksize - 1); + offset = ctx->pos & (sb->s_blocksize - 1); - while (!error && !stored && filp->f_pos < inode->i_size) { - unsigned long blk = filp->f_pos >> EXT3_BLOCK_SIZE_BITS(sb); + while (ctx->pos < inode->i_size) { + unsigned long blk = ctx->pos >> EXT3_BLOCK_SIZE_BITS(sb); struct buffer_head map_bh; struct buffer_head *bh = NULL; @@ -129,12 +122,12 @@ static int ext3_readdir(struct file * filp, if (err > 0) { pgoff_t index = map_bh.b_blocknr >> (PAGE_CACHE_SHIFT - inode->i_blkbits); - if (!ra_has_index(&filp->f_ra, index)) + if (!ra_has_index(&file->f_ra, index)) page_cache_sync_readahead( sb->s_bdev->bd_inode->i_mapping, - &filp->f_ra, filp, + &file->f_ra, file, index, 1); - filp->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT; + file->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT; bh = ext3_bread(NULL, inode, blk, 0, &err); } @@ -146,22 +139,21 @@ static int ext3_readdir(struct file * filp, if (!dir_has_error) { ext3_error(sb, __func__, "directory #%lu " "contains a hole at offset %lld", - inode->i_ino, filp->f_pos); + inode->i_ino, ctx->pos); dir_has_error = 1; } /* corrupt size? Maybe no more blocks to read */ - if (filp->f_pos > inode->i_blocks << 9) + if (ctx->pos > inode->i_blocks << 9) break; - filp->f_pos += sb->s_blocksize - offset; + ctx->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) { + if (offset && file->f_version != inode->i_version) { for (i = 0; i < sb->s_blocksize && i < offset; ) { de = (struct ext3_dir_entry_2 *) (bh->b_data + i); @@ -177,53 +169,40 @@ revalidate: i += ext3_rec_len_from_disk(de->rec_len); } offset = i; - filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1)) + ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) | offset; - filp->f_version = inode->i_version; + file->f_version = inode->i_version; } - while (!error && filp->f_pos < inode->i_size + while (ctx->pos < inode->i_size && offset < sb->s_blocksize) { de = (struct ext3_dir_entry_2 *) (bh->b_data + offset); if (!ext3_check_dir_entry ("ext3_readdir", inode, de, bh, offset)) { - /* On error, skip the f_pos to the + /* On error, skip the to the next block. */ - filp->f_pos = (filp->f_pos | + ctx->pos = (ctx->pos | (sb->s_blocksize - 1)) + 1; - brelse (bh); - ret = stored; - goto out; + break; } offset += ext3_rec_len_from_disk(de->rec_len); 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 ++; + if (!dir_emit(ctx, de->name, de->name_len, + le32_to_cpu(de->inode), + get_dtype(sb, de->file_type))) { + brelse(bh); + return 0; + } } - filp->f_pos += ext3_rec_len_from_disk(de->rec_len); + ctx->pos += ext3_rec_len_from_disk(de->rec_len); } offset = 0; brelse (bh); + if (ctx->pos < inode->i_size) + if (!dir_relax(inode)) + return 0; } -out: - return ret; + return 0; } static inline int is_32bit_api(void) @@ -452,62 +431,54 @@ int ext3_htree_store_dirent(struct file *dir_file, __u32 hash, * 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) +static bool call_filldir(struct file *file, struct dir_context *ctx, + struct fname *fname) { - struct dir_private_info *info = filp->private_data; - loff_t curr_pos; - struct inode *inode = file_inode(filp); - struct super_block * sb; - int error; - - sb = inode->i_sb; + struct dir_private_info *info = file->private_data; + struct inode *inode = file_inode(file); + struct super_block *sb = inode->i_sb; if (!fname) { printk("call_filldir: called with null fname?!?\n"); - return 0; + return true; } - curr_pos = hash2pos(filp, fname->hash, fname->minor_hash); + ctx->pos = hash2pos(file, fname->hash, fname->minor_hash); while (fname) { - error = filldir(dirent, fname->name, - fname->name_len, curr_pos, + if (!dir_emit(ctx, fname->name, fname->name_len, fname->inode, - get_dtype(sb, fname->file_type)); - if (error) { - filp->f_pos = curr_pos; + get_dtype(sb, fname->file_type))) { info->extra_fname = fname; - return error; + return false; } fname = fname->next; } - return 0; + return true; } -static int ext3_dx_readdir(struct file * filp, - void * dirent, filldir_t filldir) +static int ext3_dx_readdir(struct file *file, struct dir_context *ctx) { - struct dir_private_info *info = filp->private_data; - struct inode *inode = file_inode(filp); + struct dir_private_info *info = file->private_data; + struct inode *inode = file_inode(file); struct fname *fname; int ret; if (!info) { - info = ext3_htree_create_dir_info(filp, filp->f_pos); + info = ext3_htree_create_dir_info(file, ctx->pos); if (!info) return -ENOMEM; - filp->private_data = info; + file->private_data = info; } - if (filp->f_pos == ext3_get_htree_eof(filp)) + if (ctx->pos == ext3_get_htree_eof(file)) return 0; /* EOF */ /* Some one has messed with f_pos; reset the world */ - if (info->last_pos != filp->f_pos) { + if (info->last_pos != ctx->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); + info->curr_hash = pos2maj_hash(file, ctx->pos); + info->curr_minor_hash = pos2min_hash(file, ctx->pos); } /* @@ -515,7 +486,7 @@ static int ext3_dx_readdir(struct file * filp, * chain, return them first. */ if (info->extra_fname) { - if (call_filldir(filp, dirent, filldir, info->extra_fname)) + if (!call_filldir(file, ctx, info->extra_fname)) goto finished; info->extra_fname = NULL; goto next_node; @@ -529,17 +500,17 @@ static int ext3_dx_readdir(struct file * filp, * cached entries. */ if ((!info->curr_node) || - (filp->f_version != inode->i_version)) { + (file->f_version != inode->i_version)) { info->curr_node = NULL; free_rb_tree_fname(&info->root); - filp->f_version = inode->i_version; - ret = ext3_htree_fill_tree(filp, info->curr_hash, + file->f_version = inode->i_version; + ret = ext3_htree_fill_tree(file, info->curr_hash, info->curr_minor_hash, &info->next_hash); if (ret < 0) return ret; if (ret == 0) { - filp->f_pos = ext3_get_htree_eof(filp); + ctx->pos = ext3_get_htree_eof(file); break; } info->curr_node = rb_first(&info->root); @@ -548,7 +519,7 @@ static int ext3_dx_readdir(struct file * filp, 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)) + if (!call_filldir(file, ctx, fname)) break; next_node: info->curr_node = rb_next(info->curr_node); @@ -559,7 +530,7 @@ static int ext3_dx_readdir(struct file * filp, info->curr_minor_hash = fname->minor_hash; } else { if (info->next_hash == ~0) { - filp->f_pos = ext3_get_htree_eof(filp); + ctx->pos = ext3_get_htree_eof(file); break; } info->curr_hash = info->next_hash; @@ -567,7 +538,7 @@ static int ext3_dx_readdir(struct file * filp, } } finished: - info->last_pos = filp->f_pos; + info->last_pos = ctx->pos; return 0; } @@ -582,7 +553,7 @@ static int ext3_release_dir (struct inode * inode, struct file * filp) const struct file_operations ext3_dir_operations = { .llseek = ext3_dir_llseek, .read = generic_read_dir, - .readdir = ext3_readdir, + .iterate = ext3_readdir, .unlocked_ioctl = ext3_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = ext3_compat_ioctl, -- cgit v1.2.3