fs/reiserfs/dir.c - kernel/lockdown - Git at Google

 /*
  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
  */

 #include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include "reiserfs.h"
 #include <linux/stat.h>
 #include <linux/buffer_head.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>

 extern const struct reiserfs_key MIN_KEY;

 static int reiserfs_readdir(struct file *, struct dir_context *);
 static int reiserfs_dir_fsync(struct file *filp, loff_t start, loff_t end,
 			      int datasync);

 const struct file_operations reiserfs_dir_operations = {
 	.llseek = generic_file_llseek,
 	.read = generic_read_dir,
 	.iterate = reiserfs_readdir,
 	.fsync = reiserfs_dir_fsync,
 	.unlocked_ioctl = reiserfs_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = reiserfs_compat_ioctl,
 #endif
 };

 static int reiserfs_dir_fsync(struct file *filp, loff_t start, loff_t end,
 			      int datasync)
 {
 	struct inode *inode = filp->f_mapping->host;
 	int err;

 	err = filemap_write_and_wait_range(inode->i_mapping, start, end);
 	if (err)
 		return err;

 	mutex_lock(&inode->i_mutex);
 	reiserfs_write_lock(inode->i_sb);
 	err = reiserfs_commit_for_inode(inode);
 	reiserfs_write_unlock(inode->i_sb);
 	mutex_unlock(&inode->i_mutex);
 	if (err < 0)
 		return err;
 	return 0;
 }

 #define store_ih(where,what) copy_item_head (where, what)

 static inline bool is_privroot_deh(struct inode *dir, struct reiserfs_de_head *deh)
 {
 	struct dentry *privroot = REISERFS_SB(dir->i_sb)->priv_root;
 	return (d_really_is_positive(privroot) &&
 	        deh->deh_objectid == INODE_PKEY(d_inode(privroot))->k_objectid);
 }

 int reiserfs_readdir_inode(struct inode *inode, struct dir_context *ctx)
 {

 	/* key of current position in the directory (key of directory entry) */
 	struct cpu_key pos_key;

 	INITIALIZE_PATH(path_to_entry);
 	struct buffer_head *bh;
 	int item_num, entry_num;
 	const struct reiserfs_key *rkey;
 	struct item_head *ih, tmp_ih;
 	int search_res;
 	char *local_buf;
 	loff_t next_pos;
 	char small_buf[32];	/* avoid kmalloc if we can */
 	struct reiserfs_dir_entry de;
 	int ret = 0;
 	int depth;

 	reiserfs_write_lock(inode->i_sb);

 	reiserfs_check_lock_depth(inode->i_sb, "readdir");

 	/*
 	 * form key for search the next directory entry using
 	 * f_pos field of file structure
 	 */
 	make_cpu_key(&pos_key, inode, ctx->pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3);
 	next_pos = cpu_key_k_offset(&pos_key);

 	path_to_entry.reada = PATH_READA;
 	while (1) {
 research:
 		/*
 		 * search the directory item, containing entry with
 		 * specified key
 		 */
 		search_res =
 		    search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
 					&de);
 		if (search_res == IO_ERROR) {
 			/*
 			 * FIXME: we could just skip part of directory
 			 * which could not be read
 			 */
 			ret = -EIO;
 			goto out;
 		}
 		entry_num = de.de_entry_num;
 		bh = de.de_bh;
 		item_num = de.de_item_num;
 		ih = de.de_ih;
 		store_ih(&tmp_ih, ih);

 		/* we must have found item, that is item of this directory, */
 		RFALSE(COMP_SHORT_KEYS(&ih->ih_key, &pos_key),
 		       "vs-9000: found item %h does not match to dir we readdir %K",
 		       ih, &pos_key);
 		RFALSE(item_num > B_NR_ITEMS(bh) - 1,
 		       "vs-9005 item_num == %d, item amount == %d",
 		       item_num, B_NR_ITEMS(bh));

 		/*
 		 * and entry must be not more than number of entries
 		 * in the item
 		 */
 		RFALSE(ih_entry_count(ih) < entry_num,
 		       "vs-9010: entry number is too big %d (%d)",
 		       entry_num, ih_entry_count(ih));

 		/*
 		 * go through all entries in the directory item beginning
 		 * from the entry, that has been found
 		 */
 		if (search_res == POSITION_FOUND
 		    || entry_num < ih_entry_count(ih)) {
 			struct reiserfs_de_head *deh =
 			    B_I_DEH(bh, ih) + entry_num;

 			for (; entry_num < ih_entry_count(ih);
 			     entry_num++, deh++) {
 				int d_reclen;
 				char *d_name;
 				ino_t d_ino;
 				loff_t cur_pos = deh_offset(deh);

 				/* it is hidden entry */
 				if (!de_visible(deh))
 					continue;
 				d_reclen = entry_length(bh, ih, entry_num);
 				d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);

 				if (d_reclen <= 0 ||
 				    d_name + d_reclen > bh->b_data + bh->b_size) {
 					/*
 					 * There is corrupted data in entry,
 					 * We'd better stop here
 					 */
 					pathrelse(&path_to_entry);
 					ret = -EIO;
 					goto out;
 				}

 				if (!d_name[d_reclen - 1])
 					d_reclen = strlen(d_name);

 				/* too big to send back to VFS */
 				if (d_reclen >
 				    REISERFS_MAX_NAME(inode->i_sb->
 						      s_blocksize)) {
 					continue;
 				}

 				/* Ignore the .reiserfs_priv entry */
 				if (is_privroot_deh(inode, deh))
 					continue;

 				ctx->pos = deh_offset(deh);
 				d_ino = deh_objectid(deh);
 				if (d_reclen <= 32) {
 					local_buf = small_buf;
 				} else {
 					local_buf = kmalloc(d_reclen,
 							    GFP_NOFS);
 					if (!local_buf) {
 						pathrelse(&path_to_entry);
 						ret = -ENOMEM;
 						goto out;
 					}
 					if (item_moved(&tmp_ih, &path_to_entry)) {
 						kfree(local_buf);
 						goto research;
 					}
 				}

 				/*
 				 * Note, that we copy name to user space via
 				 * temporary buffer (local_buf) because
 				 * filldir will block if user space buffer is
 				 * swapped out. At that time entry can move to
 				 * somewhere else
 				 */
 				memcpy(local_buf, d_name, d_reclen);

 				/*
 				 * Since filldir might sleep, we can release
 				 * the write lock here for other waiters
 				 */
 				depth = reiserfs_write_unlock_nested(inode->i_sb);
 				if (!dir_emit
 				    (ctx, local_buf, d_reclen, d_ino,
 				     DT_UNKNOWN)) {
 					reiserfs_write_lock_nested(inode->i_sb, depth);
 					if (local_buf != small_buf) {
 						kfree(local_buf);
 					}
 					goto end;
 				}
 				reiserfs_write_lock_nested(inode->i_sb, depth);
 				if (local_buf != small_buf) {
 					kfree(local_buf);
 				}

 				/* deh_offset(deh) may be invalid now. */
 				next_pos = cur_pos + 1;

 				if (item_moved(&tmp_ih, &path_to_entry)) {
 					set_cpu_key_k_offset(&pos_key,
 							     next_pos);
 					goto research;
 				}
 			}	/* for */
 		}

 		/* end of directory has been reached */
 		if (item_num != B_NR_ITEMS(bh) - 1)
 			goto end;

 		/*
 		 * item we went through is last item of node. Using right
 		 * delimiting key check is it directory end
 		 */
 		rkey = get_rkey(&path_to_entry, inode->i_sb);
 		if (!comp_le_keys(rkey, &MIN_KEY)) {
 			/*
 			 * set pos_key to key, that is the smallest and greater
 			 * that key of the last entry in the item
 			 */
 			set_cpu_key_k_offset(&pos_key, next_pos);
 			continue;
 		}

 		/* end of directory has been reached */
 		if (COMP_SHORT_KEYS(rkey, &pos_key)) {
 			goto end;
 		}

 		/* directory continues in the right neighboring block */
 		set_cpu_key_k_offset(&pos_key,
 				     le_key_k_offset(KEY_FORMAT_3_5, rkey));

 	}			/* while */

 end:
 	ctx->pos = next_pos;
 	pathrelse(&path_to_entry);
 	reiserfs_check_path(&path_to_entry);
 out:
 	reiserfs_write_unlock(inode->i_sb);
 	return ret;
 }

 static int reiserfs_readdir(struct file *file, struct dir_context *ctx)
 {
 	return reiserfs_readdir_inode(file_inode(file), ctx);
 }

 /*
  * compose directory item containing "." and ".." entries (entries are
  * not aligned to 4 byte boundary)
  */
 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
 			    __le32 par_dirid, __le32 par_objid)
 {
 	struct reiserfs_de_head *dot, *dotdot;

 	memset(body, 0, EMPTY_DIR_SIZE_V1);
 	dot = (struct reiserfs_de_head *)body;
 	dotdot = dot + 1;

 	/* direntry header of "." */
 	put_deh_offset(dot, DOT_OFFSET);
 	/* these two are from make_le_item_head, and are are LE */
 	dot->deh_dir_id = dirid;
 	dot->deh_objectid = objid;
 	dot->deh_state = 0;	/* Endian safe if 0 */
 	put_deh_location(dot, EMPTY_DIR_SIZE_V1 - strlen("."));
 	mark_de_visible(dot);

 	/* direntry header of ".." */
 	put_deh_offset(dotdot, DOT_DOT_OFFSET);
 	/* key of ".." for the root directory */
 	/* these two are from the inode, and are are LE */
 	dotdot->deh_dir_id = par_dirid;
 	dotdot->deh_objectid = par_objid;
 	dotdot->deh_state = 0;	/* Endian safe if 0 */
 	put_deh_location(dotdot, deh_location(dot) - strlen(".."));
 	mark_de_visible(dotdot);

 	/* copy ".." and "." */
 	memcpy(body + deh_location(dot), ".", 1);
 	memcpy(body + deh_location(dotdot), "..", 2);
 }

 /* compose directory item containing "." and ".." entries */
 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
 			 __le32 par_dirid, __le32 par_objid)
 {
 	struct reiserfs_de_head *dot, *dotdot;

 	memset(body, 0, EMPTY_DIR_SIZE);
 	dot = (struct reiserfs_de_head *)body;
 	dotdot = dot + 1;

 	/* direntry header of "." */
 	put_deh_offset(dot, DOT_OFFSET);
 	/* these two are from make_le_item_head, and are are LE */
 	dot->deh_dir_id = dirid;
 	dot->deh_objectid = objid;
 	dot->deh_state = 0;	/* Endian safe if 0 */
 	put_deh_location(dot, EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
 	mark_de_visible(dot);

 	/* direntry header of ".." */
 	put_deh_offset(dotdot, DOT_DOT_OFFSET);
 	/* key of ".." for the root directory */
 	/* these two are from the inode, and are are LE */
 	dotdot->deh_dir_id = par_dirid;
 	dotdot->deh_objectid = par_objid;
 	dotdot->deh_state = 0;	/* Endian safe if 0 */
 	put_deh_location(dotdot, deh_location(dot) - ROUND_UP(strlen("..")));
 	mark_de_visible(dotdot);

 	/* copy ".." and "." */
 	memcpy(body + deh_location(dot), ".", 1);
 	memcpy(body + deh_location(dotdot), "..", 2);
 }
	/*
	* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
	*/

	#include <linux/string.h>
	#include <linux/errno.h>
	#include <linux/fs.h>
	#include "reiserfs.h"
	#include <linux/stat.h>
	#include <linux/buffer_head.h>
	#include <linux/slab.h>
	#include <linux/uaccess.h>

	extern const struct reiserfs_key MIN_KEY;

	static int reiserfs_readdir(struct file , struct dir_context );
	static int reiserfs_dir_fsync(struct file *filp, loff_t start, loff_t end,
	int datasync);

	const struct file_operations reiserfs_dir_operations = {
	.llseek = generic_file_llseek,
	.read = generic_read_dir,
	.iterate = reiserfs_readdir,
	.fsync = reiserfs_dir_fsync,
	.unlocked_ioctl = reiserfs_ioctl,
	#ifdef CONFIG_COMPAT
	.compat_ioctl = reiserfs_compat_ioctl,
	#endif
	};

	static int reiserfs_dir_fsync(struct file *filp, loff_t start, loff_t end,
	int datasync)
	{
	struct inode *inode = filp->f_mapping->host;
	int err;

	err = filemap_write_and_wait_range(inode->i_mapping, start, end);
	if (err)
	return err;

	mutex_lock(&inode->i_mutex);
	reiserfs_write_lock(inode->i_sb);
	err = reiserfs_commit_for_inode(inode);
	reiserfs_write_unlock(inode->i_sb);
	mutex_unlock(&inode->i_mutex);
	if (err < 0)
	return err;
	return 0;
	}

	#define store_ih(where,what) copy_item_head (where, what)

	static inline bool is_privroot_deh(struct inode dir, struct reiserfs_de_head deh)
	{
	struct dentry *privroot = REISERFS_SB(dir->i_sb)->priv_root;
	return (d_really_is_positive(privroot) &&
	deh->deh_objectid == INODE_PKEY(d_inode(privroot))->k_objectid);
	}

	int reiserfs_readdir_inode(struct inode inode, struct dir_context ctx)
	{

	/* key of current position in the directory (key of directory entry) */
	struct cpu_key pos_key;

	INITIALIZE_PATH(path_to_entry);
	struct buffer_head *bh;
	int item_num, entry_num;
	const struct reiserfs_key *rkey;
	struct item_head *ih, tmp_ih;
	int search_res;
	char *local_buf;
	loff_t next_pos;
	char small_buf[32]; /* avoid kmalloc if we can */
	struct reiserfs_dir_entry de;
	int ret = 0;
	int depth;

	reiserfs_write_lock(inode->i_sb);

	reiserfs_check_lock_depth(inode->i_sb, "readdir");

	/*
	* form key for search the next directory entry using
	* f_pos field of file structure
	*/
	make_cpu_key(&pos_key, inode, ctx->pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3);
	next_pos = cpu_key_k_offset(&pos_key);

	path_to_entry.reada = PATH_READA;
	while (1) {
	research:
	/*
	* search the directory item, containing entry with
	* specified key
	*/
	search_res =
	search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
	&de);
	if (search_res == IO_ERROR) {
	/*
	* FIXME: we could just skip part of directory
	* which could not be read
	*/
	ret = -EIO;
	goto out;
	}
	entry_num = de.de_entry_num;
	bh = de.de_bh;
	item_num = de.de_item_num;
	ih = de.de_ih;
	store_ih(&tmp_ih, ih);

	/* we must have found item, that is item of this directory, */
	RFALSE(COMP_SHORT_KEYS(&ih->ih_key, &pos_key),
	"vs-9000: found item %h does not match to dir we readdir %K",
	ih, &pos_key);
	RFALSE(item_num > B_NR_ITEMS(bh) - 1,
	"vs-9005 item_num == %d, item amount == %d",
	item_num, B_NR_ITEMS(bh));

	/*
	* and entry must be not more than number of entries
	* in the item
	*/
	RFALSE(ih_entry_count(ih) < entry_num,
	"vs-9010: entry number is too big %d (%d)",
	entry_num, ih_entry_count(ih));

	/*
	* go through all entries in the directory item beginning
	* from the entry, that has been found
	*/
	if (search_res == POSITION_FOUND
	\|\| entry_num < ih_entry_count(ih)) {
	struct reiserfs_de_head *deh =
	B_I_DEH(bh, ih) + entry_num;

	for (; entry_num < ih_entry_count(ih);
	entry_num++, deh++) {
	int d_reclen;
	char *d_name;
	ino_t d_ino;
	loff_t cur_pos = deh_offset(deh);

	/* it is hidden entry */
	if (!de_visible(deh))
	continue;
	d_reclen = entry_length(bh, ih, entry_num);
	d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);

	if (d_reclen <= 0 \|\|
	d_name + d_reclen > bh->b_data + bh->b_size) {
	/*
	* There is corrupted data in entry,
	* We'd better stop here
	*/
	pathrelse(&path_to_entry);
	ret = -EIO;
	goto out;
	}

	if (!d_name[d_reclen - 1])
	d_reclen = strlen(d_name);

	/* too big to send back to VFS */
	if (d_reclen >
	REISERFS_MAX_NAME(inode->i_sb->
	s_blocksize)) {
	continue;
	}

	/* Ignore the .reiserfs_priv entry */
	if (is_privroot_deh(inode, deh))
	continue;

	ctx->pos = deh_offset(deh);
	d_ino = deh_objectid(deh);
	if (d_reclen <= 32) {
	local_buf = small_buf;
	} else {
	local_buf = kmalloc(d_reclen,
	GFP_NOFS);
	if (!local_buf) {
	pathrelse(&path_to_entry);
	ret = -ENOMEM;
	goto out;
	}
	if (item_moved(&tmp_ih, &path_to_entry)) {
	kfree(local_buf);
	goto research;
	}
	}

	/*
	* Note, that we copy name to user space via
	* temporary buffer (local_buf) because
	* filldir will block if user space buffer is
	* swapped out. At that time entry can move to
	* somewhere else
	*/
	memcpy(local_buf, d_name, d_reclen);

	/*
	* Since filldir might sleep, we can release
	* the write lock here for other waiters
	*/
	depth = reiserfs_write_unlock_nested(inode->i_sb);
	if (!dir_emit
	(ctx, local_buf, d_reclen, d_ino,
	DT_UNKNOWN)) {
	reiserfs_write_lock_nested(inode->i_sb, depth);
	if (local_buf != small_buf) {
	kfree(local_buf);
	}
	goto end;
	}
	reiserfs_write_lock_nested(inode->i_sb, depth);
	if (local_buf != small_buf) {
	kfree(local_buf);
	}

	/* deh_offset(deh) may be invalid now. */
	next_pos = cur_pos + 1;

	if (item_moved(&tmp_ih, &path_to_entry)) {
	set_cpu_key_k_offset(&pos_key,
	next_pos);
	goto research;
	}
	} /* for */
	}

	/* end of directory has been reached */
	if (item_num != B_NR_ITEMS(bh) - 1)
	goto end;

	/*
	* item we went through is last item of node. Using right
	* delimiting key check is it directory end
	*/
	rkey = get_rkey(&path_to_entry, inode->i_sb);
	if (!comp_le_keys(rkey, &MIN_KEY)) {
	/*
	* set pos_key to key, that is the smallest and greater
	* that key of the last entry in the item
	*/
	set_cpu_key_k_offset(&pos_key, next_pos);
	continue;
	}

	/* end of directory has been reached */
	if (COMP_SHORT_KEYS(rkey, &pos_key)) {
	goto end;
	}

	/* directory continues in the right neighboring block */
	set_cpu_key_k_offset(&pos_key,
	le_key_k_offset(KEY_FORMAT_3_5, rkey));

	} /* while */

	end:
	ctx->pos = next_pos;
	pathrelse(&path_to_entry);
	reiserfs_check_path(&path_to_entry);
	out:
	reiserfs_write_unlock(inode->i_sb);
	return ret;
	}

	static int reiserfs_readdir(struct file file, struct dir_context ctx)
	{
	return reiserfs_readdir_inode(file_inode(file), ctx);
	}

	/*
	* compose directory item containing "." and ".." entries (entries are
	* not aligned to 4 byte boundary)
	*/
	void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
	__le32 par_dirid, __le32 par_objid)
	{
	struct reiserfs_de_head dot, dotdot;

	memset(body, 0, EMPTY_DIR_SIZE_V1);
	dot = (struct reiserfs_de_head *)body;
	dotdot = dot + 1;

	/* direntry header of "." */
	put_deh_offset(dot, DOT_OFFSET);
	/* these two are from make_le_item_head, and are are LE */
	dot->deh_dir_id = dirid;
	dot->deh_objectid = objid;
	dot->deh_state = 0; /* Endian safe if 0 */
	put_deh_location(dot, EMPTY_DIR_SIZE_V1 - strlen("."));
	mark_de_visible(dot);

	/* direntry header of ".." */
	put_deh_offset(dotdot, DOT_DOT_OFFSET);
	/* key of ".." for the root directory */
	/* these two are from the inode, and are are LE */
	dotdot->deh_dir_id = par_dirid;
	dotdot->deh_objectid = par_objid;
	dotdot->deh_state = 0; /* Endian safe if 0 */
	put_deh_location(dotdot, deh_location(dot) - strlen(".."));
	mark_de_visible(dotdot);

	/* copy ".." and "." */
	memcpy(body + deh_location(dot), ".", 1);
	memcpy(body + deh_location(dotdot), "..", 2);
	}

	/* compose directory item containing "." and ".." entries */
	void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
	__le32 par_dirid, __le32 par_objid)
	{
	struct reiserfs_de_head dot, dotdot;

	memset(body, 0, EMPTY_DIR_SIZE);
	dot = (struct reiserfs_de_head *)body;
	dotdot = dot + 1;

	/* direntry header of "." */
	put_deh_offset(dot, DOT_OFFSET);
	/* these two are from make_le_item_head, and are are LE */
	dot->deh_dir_id = dirid;
	dot->deh_objectid = objid;
	dot->deh_state = 0; /* Endian safe if 0 */
	put_deh_location(dot, EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
	mark_de_visible(dot);

	/* direntry header of ".." */
	put_deh_offset(dotdot, DOT_DOT_OFFSET);
	/* key of ".." for the root directory */
	/* these two are from the inode, and are are LE */
	dotdot->deh_dir_id = par_dirid;
	dotdot->deh_objectid = par_objid;
	dotdot->deh_state = 0; /* Endian safe if 0 */
	put_deh_location(dotdot, deh_location(dot) - ROUND_UP(strlen("..")));
	mark_de_visible(dotdot);

	/* copy ".." and "." */
	memcpy(body + deh_location(dot), ".", 1);
	memcpy(body + deh_location(dotdot), "..", 2);
	}