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/*
* 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 <asm/uaccess.h>
extern struct key MIN_KEY;
static int reiserfs_readdir (struct file *, void *, filldir_t);
int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry, int datasync) ;
struct file_operations reiserfs_dir_operations = {
read: generic_read_dir,
readdir: reiserfs_readdir,
fsync: reiserfs_dir_fsync,
};
int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry, int datasync) {
lock_kernel();
reiserfs_commit_for_inode(dentry->d_inode) ;
unlock_kernel() ;
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 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;
reiserfs_check_lock_depth("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 ("reiserfs_readdir 1: f_pos = %Ld\n", filp->f_pos);*/
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
return -EIO;
}
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_LEN(inode->i_sb->s_blocksize)){
/* too big to send back to VFS */
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);
return -ENOMEM ;
}
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:
// FIXME: ext2_readdir does not reset f_pos
filp->f_pos = next_pos;
pathrelse (&path_to_entry);
reiserfs_check_path(&path_to_entry) ;
return 0;
}
/* 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, __u32 dirid, __u32 objid,
__u32 par_dirid, __u32 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, __u32 dirid, __u32 objid,
__u32 par_dirid, __u32 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);
}
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