[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / reiserfs / dir.c

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

#include <linux/config.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/reiserfs_fs.h>
#include <linux/stat.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include <asm/uaccess.h>

extern struct reiserfs_key MIN_KEY;

static int reiserfs_readdir(struct file *, void *, filldir_t);
static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
			      int datasync);

const struct file_operations reiserfs_dir_operations = {
	.read = generic_read_dir,
	.readdir = reiserfs_readdir,
	.fsync = reiserfs_dir_fsync,
	.ioctl = reiserfs_ioctl,
};

static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
			      int datasync)
{
	struct inode *inode = dentry->d_inode;
	int err;
	reiserfs_write_lock(inode->i_sb);
	err = reiserfs_commit_for_inode(inode);
	reiserfs_write_unlock(inode->i_sb);
	if (err < 0)
		return err;
	return 0;
}

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

//
static int reiserfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
	struct inode *inode = filp->f_dentry->d_inode;
	struct cpu_key pos_key;	/* key of current position in the directory (key of directory entry) */
	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;

	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,
		     (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET, TYPE_DIRENTRY,
		     3);
	next_pos = cpu_key_k_offset(&pos_key);

	/*  reiserfs_warning (inode->i_sb, "reiserfs_readdir 1: f_pos = %Ld", filp->f_pos); */

	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(I_ENTRY_COUNT(ih) < entry_num,
		       "vs-9010: entry number is too big %d (%d)",
		       entry_num, I_ENTRY_COUNT(ih));

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

			for (; entry_num < I_ENTRY_COUNT(ih);
			     entry_num++, deh++) {
				int d_reclen;
				char *d_name;
				off_t d_off;
				ino_t d_ino;

				if (!de_visible(deh))
					/* it is hidden entry */
					continue;
				d_reclen = entry_length(bh, ih, entry_num);
				d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
				if (!d_name[d_reclen - 1])
					d_reclen = strlen(d_name);

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

				/* Ignore the .reiserfs_priv entry */
				if (reiserfs_xattrs(inode->i_sb) &&
				    !old_format_only(inode->i_sb) &&
				    filp->f_dentry == inode->i_sb->s_root &&
				    REISERFS_SB(inode->i_sb)->priv_root &&
				    REISERFS_SB(inode->i_sb)->priv_root->d_inode
				    && deh_objectid(deh) ==
				    le32_to_cpu(INODE_PKEY
						(REISERFS_SB(inode->i_sb)->
						 priv_root->d_inode)->
						k_objectid)) {
					continue;
				}

				d_off = deh_offset(deh);
				filp->f_pos = d_off;
				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);
				if (filldir
				    (dirent, local_buf, d_reclen, d_off, d_ino,
				     DT_UNKNOWN) < 0) {
					if (local_buf != small_buf) {
						kfree(local_buf);
					}
					goto end;
				}
				if (local_buf != small_buf) {
					kfree(local_buf);
				}
				// next entry should be looked for with such offset
				next_pos = deh_offset(deh) + 1;

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

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

		if (COMP_SHORT_KEYS(rkey, &pos_key)) {
			// end of directory has been reached
			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:
	filp->f_pos = next_pos;
	pathrelse(&path_to_entry);
	reiserfs_check_path(&path_to_entry);
      out:
	reiserfs_write_unlock(inode->i_sb);
	return ret;
}

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

	memset(body, 0, EMPTY_DIR_SIZE_V1);
	deh = (struct reiserfs_de_head *)body;

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

	/* direntry header of ".." */
	put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
	/* key of ".." for the root directory */
	/* these two are from the inode, and are are LE */
	deh[1].deh_dir_id = par_dirid;
	deh[1].deh_objectid = par_objid;
	deh[1].deh_state = 0;	/* Endian safe if 0 */
	put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
	mark_de_visible(&(deh[1]));

	/* copy ".." and "." */
	memcpy(body + deh_location(&(deh[0])), ".", 1);
	memcpy(body + deh_location(&(deh[1])), "..", 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 *deh;

	memset(body, 0, EMPTY_DIR_SIZE);
	deh = (struct reiserfs_de_head *)body;

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

	/* direntry header of ".." */
	put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
	/* key of ".." for the root directory */
	/* these two are from the inode, and are are LE */
	deh[1].deh_dir_id = par_dirid;
	deh[1].deh_objectid = par_objid;
	deh[1].deh_state = 0;	/* Endian safe if 0 */
	put_deh_location(&(deh[1]),
			 deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
	mark_de_visible(&(deh[1]));

	/* copy ".." and "." */
	memcpy(body + deh_location(&(deh[0])), ".", 1);
	memcpy(body + deh_location(&(deh[1])), "..", 2);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
	3	*/
	4
	5	#include <linux/config.h>
	6	#include <linux/string.h>
	7	#include <linux/errno.h>
	8	#include <linux/fs.h>
	9	#include <linux/reiserfs_fs.h>
	10	#include <linux/stat.h>
	11	#include <linux/smp_lock.h>
	12	#include <linux/buffer_head.h>
	13	#include <asm/uaccess.h>
	14
bd4c625c	15	extern struct reiserfs_key MIN_KEY;
1da177e4	16
bd4c625c LT	17	static int reiserfs_readdir(struct file , void , filldir_t);
	18	static int reiserfs_dir_fsync(struct file filp, struct dentry dentry,
	19	int datasync);
1da177e4	20
4b6f5d20	21	const struct file_operations reiserfs_dir_operations = {
bd4c625c LT	22	.read = generic_read_dir,
	23	.readdir = reiserfs_readdir,
	24	.fsync = reiserfs_dir_fsync,
	25	.ioctl = reiserfs_ioctl,
1da177e4 LT	26	};
1da177e4 LT	27
bd4c625c LT	28	static int reiserfs_dir_fsync(struct file filp, struct dentry dentry,
	29	int datasync)
	30	{
	31	struct inode *inode = dentry->d_inode;
	32	int err;
	33	reiserfs_write_lock(inode->i_sb);
	34	err = reiserfs_commit_for_inode(inode);
	35	reiserfs_write_unlock(inode->i_sb);
	36	if (err < 0)
	37	return err;
	38	return 0;
1da177e4 LT	39	}
1da177e4 LT	40
1da177e4 LT	41	#define store_ih(where,what) copy_item_head (where, what)
	42
	43	//
bd4c625c	44	static int reiserfs_readdir(struct file filp, void dirent, filldir_t filldir)
1da177e4	45	{
bd4c625c LT	46	struct inode *inode = filp->f_dentry->d_inode;
	47	struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
	48	INITIALIZE_PATH(path_to_entry);
	49	struct buffer_head *bh;
	50	int item_num, entry_num;
	51	const struct reiserfs_key *rkey;
	52	struct item_head *ih, tmp_ih;
	53	int search_res;
	54	char *local_buf;
	55	loff_t next_pos;
	56	char small_buf[32]; /* avoid kmalloc if we can */
	57	struct reiserfs_dir_entry de;
	58	int ret = 0;
	59
	60	reiserfs_write_lock(inode->i_sb);
	61
	62	reiserfs_check_lock_depth(inode->i_sb, "readdir");
	63
	64	/* form key for search the next directory entry using f_pos field of
	65	file structure */
	66	make_cpu_key(&pos_key, inode,
	67	(filp->f_pos) ? (filp->f_pos) : DOT_OFFSET, TYPE_DIRENTRY,
	68	3);
	69	next_pos = cpu_key_k_offset(&pos_key);
	70
	71	/* reiserfs_warning (inode->i_sb, "reiserfs_readdir 1: f_pos = %Ld", filp->f_pos); */
	72
	73	path_to_entry.reada = PATH_READA;
	74	while (1) {
	75	research:
	76	/* search the directory item, containing entry with specified key */
	77	search_res =
	78	search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
	79	&de);
	80	if (search_res == IO_ERROR) {
	81	// FIXME: we could just skip part of directory which could
	82	// not be read
	83	ret = -EIO;
1da177e4	84	goto out;
1da177e4	85	}
bd4c625c LT	86	entry_num = de.de_entry_num;
	87	bh = de.de_bh;
	88	item_num = de.de_item_num;
	89	ih = de.de_ih;
	90	store_ih(&tmp_ih, ih);
	91
	92	/* we must have found item, that is item of this directory, */
	93	RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
	94	"vs-9000: found item %h does not match to dir we readdir %K",
	95	ih, &pos_key);
	96	RFALSE(item_num > B_NR_ITEMS(bh) - 1,
	97	"vs-9005 item_num == %d, item amount == %d",
	98	item_num, B_NR_ITEMS(bh));
	99
	100	/* and entry must be not more than number of entries in the item */
	101	RFALSE(I_ENTRY_COUNT(ih) < entry_num,
	102	"vs-9010: entry number is too big %d (%d)",
	103	entry_num, I_ENTRY_COUNT(ih));
	104
	105	if (search_res == POSITION_FOUND
	106	\|\| entry_num < I_ENTRY_COUNT(ih)) {
	107	/* go through all entries in the directory item beginning from the entry, that has been found */
	108	struct reiserfs_de_head *deh =
	109	B_I_DEH(bh, ih) + entry_num;
	110
	111	for (; entry_num < I_ENTRY_COUNT(ih);
	112	entry_num++, deh++) {
	113	int d_reclen;
	114	char *d_name;
	115	off_t d_off;
	116	ino_t d_ino;
	117
	118	if (!de_visible(deh))
	119	/* it is hidden entry */
	120	continue;
	121	d_reclen = entry_length(bh, ih, entry_num);
	122	d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
	123	if (!d_name[d_reclen - 1])
	124	d_reclen = strlen(d_name);
	125
	126	if (d_reclen >
	127	REISERFS_MAX_NAME(inode->i_sb->
	128	s_blocksize)) {
	129	/* too big to send back to VFS */
	130	continue;
	131	}
	132
	133	/* Ignore the .reiserfs_priv entry */
	134	if (reiserfs_xattrs(inode->i_sb) &&
	135	!old_format_only(inode->i_sb) &&
	136	filp->f_dentry == inode->i_sb->s_root &&
	137	REISERFS_SB(inode->i_sb)->priv_root &&
	138	REISERFS_SB(inode->i_sb)->priv_root->d_inode
	139	&& deh_objectid(deh) ==
	140	le32_to_cpu(INODE_PKEY
	141	(REISERFS_SB(inode->i_sb)->
	142	priv_root->d_inode)->
	143	k_objectid)) {
	144	continue;
	145	}
	146
	147	d_off = deh_offset(deh);
	148	filp->f_pos = d_off;
	149	d_ino = deh_objectid(deh);
150	if (d_reclen <= 32) {
151	local_buf = small_buf;
152	} else {
d739b42b PE	153	local_buf = kmalloc(d_reclen,
d739b42b PE	154	GFP_NOFS);
bd4c625c LT	155	if (!local_buf) {
	156	pathrelse(&path_to_entry);
	157	ret = -ENOMEM;
	158	goto out;
	159	}
	160	if (item_moved(&tmp_ih, &path_to_entry)) {
d739b42b	161	kfree(local_buf);
bd4c625c LT	162	goto research;
	163	}
	164	}
	165	// Note, that we copy name to user space via temporary
	166	// buffer (local_buf) because filldir will block if
	167	// user space buffer is swapped out. At that time
	168	// entry can move to somewhere else
	169	memcpy(local_buf, d_name, d_reclen);
	170	if (filldir
	171	(dirent, local_buf, d_reclen, d_off, d_ino,
	172	DT_UNKNOWN) < 0) {
	173	if (local_buf != small_buf) {
d739b42b	174	kfree(local_buf);
bd4c625c LT	175	}
	176	goto end;
	177	}
	178	if (local_buf != small_buf) {
d739b42b	179	kfree(local_buf);
bd4c625c LT	180	}
	181	// next entry should be looked for with such offset
	182	next_pos = deh_offset(deh) + 1;
	183
	184	if (item_moved(&tmp_ih, &path_to_entry)) {
	185	goto research;
	186	}
	187	} /* for */
1da177e4 LT	188	}
1da177e4 LT	189
bd4c625c LT	190	if (item_num != B_NR_ITEMS(bh) - 1)
	191	// end of directory has been reached
	192	goto end;
	193
	194	/* item we went through is last item of node. Using right
	195	delimiting key check is it directory end */
	196	rkey = get_rkey(&path_to_entry, inode->i_sb);
	197	if (!comp_le_keys(rkey, &MIN_KEY)) {
	198	/* set pos_key to key, that is the smallest and greater
	199	that key of the last entry in the item */
	200	set_cpu_key_k_offset(&pos_key, next_pos);
	201	continue;
	202	}
1da177e4	203
bd4c625c LT	204	if (COMP_SHORT_KEYS(rkey, &pos_key)) {
	205	// end of directory has been reached
	206	goto end;
1da177e4	207	}
bd4c625c LT	208
	209	/* directory continues in the right neighboring block */
	210	set_cpu_key_k_offset(&pos_key,
	211	le_key_k_offset(KEY_FORMAT_3_5, rkey));
	212
	213	} /* while */
	214
	215	end:
	216	filp->f_pos = next_pos;
	217	pathrelse(&path_to_entry);
	218	reiserfs_check_path(&path_to_entry);
	219	out:
	220	reiserfs_write_unlock(inode->i_sb);
	221	return ret;
1da177e4 LT	222	}
	223
	224	/* compose directory item containing "." and ".." entries (entries are
	225	not aligned to 4 byte boundary) */
	226	/* the last four params are LE */
bd4c625c LT	227	void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
bd4c625c LT	228	__le32 par_dirid, __le32 par_objid)
1da177e4	229	{
bd4c625c LT	230	struct reiserfs_de_head *deh;
	231
	232	memset(body, 0, EMPTY_DIR_SIZE_V1);
	233	deh = (struct reiserfs_de_head *)body;
	234
	235	/* direntry header of "." */
	236	put_deh_offset(&(deh[0]), DOT_OFFSET);
	237	/* these two are from make_le_item_head, and are are LE */
	238	deh[0].deh_dir_id = dirid;
	239	deh[0].deh_objectid = objid;
	240	deh[0].deh_state = 0; /* Endian safe if 0 */
	241	put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
	242	mark_de_visible(&(deh[0]));
	243
	244	/* direntry header of ".." */
	245	put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
	246	/* key of ".." for the root directory */
	247	/* these two are from the inode, and are are LE */
	248	deh[1].deh_dir_id = par_dirid;
	249	deh[1].deh_objectid = par_objid;
	250	deh[1].deh_state = 0; /* Endian safe if 0 */
	251	put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
	252	mark_de_visible(&(deh[1]));
	253
	254	/* copy ".." and "." */
	255	memcpy(body + deh_location(&(deh[0])), ".", 1);
	256	memcpy(body + deh_location(&(deh[1])), "..", 2);
1da177e4 LT	257	}
	258
	259	/* compose directory item containing "." and ".." entries */
bd4c625c LT	260	void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
bd4c625c LT	261	__le32 par_dirid, __le32 par_objid)
1da177e4	262	{
bd4c625c LT	263	struct reiserfs_de_head *deh;
	264
	265	memset(body, 0, EMPTY_DIR_SIZE);
	266	deh = (struct reiserfs_de_head *)body;
	267
	268	/* direntry header of "." */
	269	put_deh_offset(&(deh[0]), DOT_OFFSET);
	270	/* these two are from make_le_item_head, and are are LE */
	271	deh[0].deh_dir_id = dirid;
	272	deh[0].deh_objectid = objid;
	273	deh[0].deh_state = 0; /* Endian safe if 0 */
	274	put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
	275	mark_de_visible(&(deh[0]));
	276
	277	/* direntry header of ".." */
	278	put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
	279	/* key of ".." for the root directory */
	280	/* these two are from the inode, and are are LE */
	281	deh[1].deh_dir_id = par_dirid;
	282	deh[1].deh_objectid = par_objid;
	283	deh[1].deh_state = 0; /* Endian safe if 0 */
	284	put_deh_location(&(deh[1]),
	285	deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
	286	mark_de_visible(&(deh[1]));
	287
	288	/* copy ".." and "." */
	289	memcpy(body + deh_location(&(deh[0])), ".", 1);
	290	memcpy(body + deh_location(&(deh[1])), "..", 2);
1da177e4	291	}