linux/fs/affs/dir.c
Arjan van de Ven 4b6f5d20b0 [PATCH] Make most file operations structs in fs/ const
This is a conversion to make the various file_operations structs in fs/
const.  Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:16:06 -08:00

155 lines
3.7 KiB
C

/*
* linux/fs/affs/dir.c
*
* (c) 1996 Hans-Joachim Widmaier - Rewritten
*
* (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
*
* (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
*
* (C) 1991 Linus Torvalds - minix filesystem
*
* affs directory handling functions
*
*/
#include "affs.h"
static int affs_readdir(struct file *, void *, filldir_t);
const struct file_operations affs_dir_operations = {
.read = generic_read_dir,
.readdir = affs_readdir,
.fsync = file_fsync,
};
/*
* directories can handle most operations...
*/
struct inode_operations affs_dir_inode_operations = {
.create = affs_create,
.lookup = affs_lookup,
.link = affs_link,
.unlink = affs_unlink,
.symlink = affs_symlink,
.mkdir = affs_mkdir,
.rmdir = affs_rmdir,
.rename = affs_rename,
.setattr = affs_notify_change,
};
static int
affs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
struct inode *inode = filp->f_dentry->d_inode;
struct super_block *sb = inode->i_sb;
struct buffer_head *dir_bh;
struct buffer_head *fh_bh;
unsigned char *name;
int namelen;
u32 i;
int hash_pos;
int chain_pos;
u32 f_pos;
u32 ino;
int stored;
int res;
pr_debug("AFFS: readdir(ino=%lu,f_pos=%lx)\n",inode->i_ino,(unsigned long)filp->f_pos);
stored = 0;
res = -EIO;
dir_bh = NULL;
fh_bh = NULL;
f_pos = filp->f_pos;
if (f_pos == 0) {
filp->private_data = (void *)0;
if (filldir(dirent, ".", 1, f_pos, inode->i_ino, DT_DIR) < 0)
return 0;
filp->f_pos = f_pos = 1;
stored++;
}
if (f_pos == 1) {
if (filldir(dirent, "..", 2, f_pos, parent_ino(filp->f_dentry), DT_DIR) < 0)
return stored;
filp->f_pos = f_pos = 2;
stored++;
}
affs_lock_dir(inode);
chain_pos = (f_pos - 2) & 0xffff;
hash_pos = (f_pos - 2) >> 16;
if (chain_pos == 0xffff) {
affs_warning(sb, "readdir", "More than 65535 entries in chain");
chain_pos = 0;
hash_pos++;
filp->f_pos = ((hash_pos << 16) | chain_pos) + 2;
}
dir_bh = affs_bread(sb, inode->i_ino);
if (!dir_bh)
goto readdir_out;
/* If the directory hasn't changed since the last call to readdir(),
* we can jump directly to where we left off.
*/
ino = (u32)(long)filp->private_data;
if (ino && filp->f_version == inode->i_version) {
pr_debug("AFFS: readdir() left off=%d\n", ino);
goto inside;
}
ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
for (i = 0; ino && i < chain_pos; i++) {
fh_bh = affs_bread(sb, ino);
if (!fh_bh) {
affs_error(sb, "readdir","Cannot read block %d", i);
goto readdir_out;
}
ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
affs_brelse(fh_bh);
fh_bh = NULL;
}
if (ino)
goto inside;
hash_pos++;
for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {
ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
if (!ino)
continue;
f_pos = (hash_pos << 16) + 2;
inside:
do {
fh_bh = affs_bread(sb, ino);
if (!fh_bh) {
affs_error(sb, "readdir","Cannot read block %d", ino);
goto readdir_done;
}
namelen = min(AFFS_TAIL(sb, fh_bh)->name[0], (u8)30);
name = AFFS_TAIL(sb, fh_bh)->name + 1;
pr_debug("AFFS: readdir(): filldir(\"%.*s\", ino=%u), hash=%d, f_pos=%x\n",
namelen, name, ino, hash_pos, f_pos);
if (filldir(dirent, name, namelen, f_pos, ino, DT_UNKNOWN) < 0)
goto readdir_done;
stored++;
f_pos++;
ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
affs_brelse(fh_bh);
fh_bh = NULL;
} while (ino);
}
readdir_done:
filp->f_pos = f_pos;
filp->f_version = inode->i_version;
filp->private_data = (void *)(long)ino;
res = stored;
readdir_out:
affs_brelse(dir_bh);
affs_brelse(fh_bh);
affs_unlock_dir(inode);
pr_debug("AFFS: readdir()=%d\n", stored);
return res;
}