- 根目录:
- fs
- affs
- amigaffs.c
/*
* linux/fs/affs/amigaffs.c
*
* (c) 1996 Hans-Joachim Widmaier - Rewritten
*
* (C) 1993 Ray Burr - Amiga FFS filesystem.
*
* Please send bug reports to: hjw@zvw.de
*/
#include "affs.h"
static char ErrorBuffer[256];
/*
* Functions for accessing Amiga-FFS structures.
*/
/* Insert a header block bh into the directory dir
* caller must hold AFFS_DIR->i_hash_lock!
*/
int
affs_insert_hash(struct inode *dir, struct buffer_head *bh)
{
struct super_block *sb = dir->i_sb;
struct buffer_head *dir_bh;
u32 ino, hash_ino;
int offset;
ino = bh->b_blocknr;
offset = affs_hash_name(sb, AFFS_TAIL(sb, bh)->name + 1, AFFS_TAIL(sb, bh)->name[0]);
pr_debug("%s(dir=%u, ino=%d)\n", __func__, (u32)dir->i_ino, ino);
dir_bh = affs_bread(sb, dir->i_ino);
if (!dir_bh)
return -EIO;
hash_ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[offset]);
while (hash_ino) {
affs_brelse(dir_bh);
dir_bh = affs_bread(sb, hash_ino);
if (!dir_bh)
return -EIO;
hash_ino = be32_to_cpu(AFFS_TAIL(sb, dir_bh)->hash_chain);
}
AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino);
AFFS_TAIL(sb, bh)->hash_chain = 0;
affs_fix_checksum(sb, bh);
if (dir->i_ino == dir_bh->b_blocknr)
AFFS_HEAD(dir_bh)->table[offset] = cpu_to_be32(ino);
else
AFFS_TAIL(sb, dir_bh)->hash_chain = cpu_to_be32(ino);
affs_adjust_checksum(dir_bh, ino);
mark_buffer_dirty_inode(dir_bh, dir);
affs_brelse(dir_bh);
dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
dir->i_version++;
mark_inode_dirty(dir);
return 0;
}
/* Remove a header block from its directory.
* caller must hold AFFS_DIR->i_hash_lock!
*/
int
affs_remove_hash(struct inode *dir, struct buffer_head *rem_bh)
{
struct super_block *sb;
struct buffer_head *bh;
u32 rem_ino, hash_ino;
__be32 ino;
int offset, retval;
sb = dir->i_sb;
rem_ino = rem_bh->b_blocknr;
offset = affs_hash_name(sb, AFFS_TAIL(sb, rem_bh)->name+1, AFFS_TAIL(sb, rem_bh)->name[0]);
pr_debug("%s(dir=%d, ino=%d, hashval=%d)\n",
__func__, (u32)dir->i_ino, rem_ino, offset);
bh = affs_bread(sb, dir->i_ino);
if (!bh)
return -EIO;
retval = -ENOENT;
hash_ino = be32_to_cpu(AFFS_HEAD(bh)->table[offset]);
while (hash_ino) {
if (hash_ino == rem_ino) {
ino = AFFS_TAIL(sb, rem_bh)->hash_chain;
if (dir->i_ino == bh->b_blocknr)
AFFS_HEAD(bh)->table[offset] = ino;
else
AFFS_TAIL(sb, bh)->hash_chain = ino;
affs_adjust_checksum(bh, be32_to_cpu(ino) - hash_ino);
mark_buffer_dirty_inode(bh, dir);
AFFS_TAIL(sb, rem_bh)->parent = 0;
retval = 0;
break;
}
affs_brelse(bh);
bh = affs_bread(sb, hash_ino);
if (!bh)
return -EIO;
hash_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
}
affs_brelse(bh);
dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
dir->i_version++;
mark_inode_dirty(dir);
return retval;
}
static void
affs_fix_dcache(struct inode *inode, u32 entry_ino)
{
struct dentry *dentry;
spin_lock(&inode->i_lock);
hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) {
if (entry_ino == (u32)(long)dentry->d_fsdata) {
dentry->d_fsdata = (void *)inode->i_ino;
break;
}
}
spin_unlock(&inode->i_lock);
}
/* Remove header from link chain */
static int
affs_remove_link(struct dentry *dentry)
{
struct inode *dir, *inode = dentry->d_inode;
struct super_block *sb = inode->i_sb;
struct buffer_head *bh = NULL, *link_bh = NULL;
u32 link_ino, ino;
int retval;
pr_debug("%s(key=%ld)\n", __func__, inode->i_ino);
retval = -EIO;
bh = affs_bread(sb, inode->i_ino);
if (!bh)
goto done;
link_ino = (u32)(long)dentry->d_fsdata;
if (inode->i_ino == link_ino) {
/* we can't remove the head of the link, as its blocknr is still used as ino,
* so we remove the block of the first link instead.
*/
link_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain);
link_bh = affs_bread(sb, link_ino);
if (!link_bh)
goto done;
dir = affs_iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent));
if (IS_ERR(dir)) {
retval = PTR_ERR(dir);
goto done;
}
affs_lock_dir(dir);
/*
* if there's a dentry for that block, make it
* refer to inode itself.
*/
affs_fix_dcache(inode, link_ino);
retval = affs_remove_hash(dir, link_bh);
if (retval) {
affs_unlock_dir(dir);
goto done;
}
mark_buffer_dirty_inode(link_bh, inode);
memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32);
retval = affs_insert_hash(dir, bh);
if (retval) {
affs_unlock_dir(dir);
goto done;
}
mark_buffer_dirty_inode(bh, inode);
affs_unlock_dir(dir);
iput(dir);
} else {
link_bh = affs_bread(sb, link_ino);
if (!link_bh)
goto done;
}
while ((ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain)) != 0) {
if (ino == link_ino) {
__be32 ino2 = AFFS_TAIL(sb, link_bh)->link_chain;
AFFS_TAIL(sb, bh)->link_chain = ino2;
affs_adjust_checksum(bh, be32_to_cpu(ino2) - link_ino);
mark_buffer_dirty_inode(bh, inode);
retval = 0;
/* Fix the link count, if bh is a normal header block without links */
switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
case ST_LINKDIR:
case ST_LINKFILE:
break;
default:
if (!AFFS_TAIL(sb, bh)->link_chain)
set_nlink(inode, 1);
}
affs_free_block(sb, link_ino);
goto done;
}
affs_brelse(bh);
bh = affs_bread(sb, ino);
if (!bh)
goto done;
}
retval = -ENOENT;
done:
affs_brelse(link_bh);
affs_brelse(bh);
return retval;
}
static int
affs_empty_dir(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
struct buffer_head *bh;
int retval, size;
retval = -EIO;
bh = affs_bread(sb, inode->i_ino);
if (!bh)
goto done;
retval = -ENOTEMPTY;
for (size = AFFS_SB(sb)->s_hashsize - 1; size >= 0; size--)
if (AFFS_HEAD(bh)->table[size])
goto not_empty;
retval = 0;
not_empty:
affs_brelse(bh);
done:
return retval;
}
/* Remove a filesystem object. If the object to be removed has
* links to it, one of the links must be changed to inherit
* the file or directory. As above, any inode will do.
* The buffer will not be freed. If the header is a link, the
* block will be marked as free.
* This function returns a negative error number in case of
* an error, else 0 if the inode is to be deleted or 1 if not.
*/
int
affs_remove_header(struct dentry *dentry)
{
struct super_block *sb;
struct inode *inode, *dir;
struct buffer_head *bh = NULL;
int retval;
dir = dentry->d_parent->d_inode;
sb = dir->i_sb;
retval = -ENOENT;
inode = dentry->d_inode;
if (!inode)
goto done;
pr_debug("%s(key=%ld)\n", __func__, inode->i_ino);
retval = -EIO;
bh = affs_bread(sb, (u32)(long)dentry->d_fsdata);
if (!bh)
goto done;
affs_lock_link(inode);
affs_lock_dir(dir);
switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
case ST_USERDIR:
/* if we ever want to support links to dirs
* i_hash_lock of the inode must only be
* taken after some checks
*/
affs_lock_dir(inode);
retval = affs_empty_dir(inode);
affs_unlock_dir(inode);
if (retval)
goto done_unlock;
break;
default:
break;
}
retval = affs_remove_hash(dir, bh);
if (retval)
goto done_unlock;
mark_buffer_dirty_inode(bh, inode);
affs_unlock_dir(dir);
if (inode->i_nlink > 1)
retval = affs_remove_link(dentry);
else
clear_nlink(inode);
affs_unlock_link(inode);
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
done:
affs_brelse(bh);
return retval;
done_unlock:
affs_unlock_dir(dir);
affs_unlock_link(inode);
goto done;
}
/* Checksum a block, do various consistency checks and optionally return
the blocks type number. DATA points to the block. If their pointers
are non-null, *PTYPE and *STYPE are set to the primary and secondary
block types respectively, *HASHSIZE is set to the size of the hashtable
(which lets us calculate the block size).
Returns non-zero if the block is not consistent. */
u32
affs_checksum_block(struct super_block *sb, struct buffer_head *bh)
{
__be32 *ptr = (__be32 *)bh->b_data;
u32 sum;
int bsize;
sum = 0;
for (bsize = sb->s_blocksize / sizeof(__be32); bsize > 0; bsize--)
sum += be32_to_cpu(*ptr++);
return sum;
}
/*
* Calculate the checksum of a disk block and store it
* at the indicated position.
*/
void
affs_fix_checksum(struct super_block *sb, struct buffer_head *bh)
{
int cnt = sb->s_blocksize / sizeof(__be32);
__be32 *ptr = (__be32 *)bh->b_data;
u32 checksum;
__be32 *checksumptr;
checksumptr = ptr + 5;
*checksumptr = 0;
for (checksum = 0; cnt > 0; ptr++, cnt--)
checksum += be32_to_cpu(*ptr);
*checksumptr = cpu_to_be32(-checksum);
}
void
secs_to_datestamp(time_t secs, struct affs_date *ds)
{
u32 days;
u32 minute;
secs -= sys_tz.tz_minuteswest * 60 + ((8 * 365 + 2) * 24 * 60 * 60);
if (secs < 0)
secs = 0;
days = secs / 86400;
secs -= days * 86400;
minute = secs / 60;
secs -= minute * 60;
ds->days = cpu_to_be32(days);
ds->mins = cpu_to_be32(minute);
ds->ticks = cpu_to_be32(secs * 50);
}
umode_t
prot_to_mode(u32 prot)
{
umode_t mode = 0;
if (!(prot & FIBF_NOWRITE))
mode |= S_IWUSR;
if (!(prot & FIBF_NOREAD))
mode |= S_IRUSR;
if (!(prot & FIBF_NOEXECUTE))
mode |= S_IXUSR;
if (prot & FIBF_GRP_WRITE)
mode |= S_IWGRP;
if (prot & FIBF_GRP_READ)
mode |= S_IRGRP;
if (prot & FIBF_GRP_EXECUTE)
mode |= S_IXGRP;
if (prot & FIBF_OTR_WRITE)
mode |= S_IWOTH;
if (prot & FIBF_OTR_READ)
mode |= S_IROTH;
if (prot & FIBF_OTR_EXECUTE)
mode |= S_IXOTH;
return mode;
}
void
mode_to_prot(struct inode *inode)
{
u32 prot = AFFS_I(inode)->i_protect;
umode_t mode = inode->i_mode;
if (!(mode & S_IXUSR))
prot |= FIBF_NOEXECUTE;
if (!(mode & S_IRUSR))
prot |= FIBF_NOREAD;
if (!(mode & S_IWUSR))
prot |= FIBF_NOWRITE;
if (mode & S_IXGRP)
prot |= FIBF_GRP_EXECUTE;
if (mode & S_IRGRP)
prot |= FIBF_GRP_READ;
if (mode & S_IWGRP)
prot |= FIBF_GRP_WRITE;
if (mode & S_IXOTH)
prot |= FIBF_OTR_EXECUTE;
if (mode & S_IROTH)
prot |= FIBF_OTR_READ;
if (mode & S_IWOTH)
prot |= FIBF_OTR_WRITE;
AFFS_I(inode)->i_protect = prot;
}
void
affs_error(struct super_block *sb, const char *function, const char *fmt, ...)
{
va_list args;
va_start(args,fmt);
vsnprintf(ErrorBuffer,sizeof(ErrorBuffer),fmt,args);
va_end(args);
pr_crit("error (device %s): %s(): %s\n", sb->s_id,
function,ErrorBuffer);
if (!(sb->s_flags & MS_RDONLY))
pr_warn("Remounting filesystem read-only\n");
sb->s_flags |= MS_RDONLY;
}
void
affs_warning(struct super_block *sb, const char *function, const char *fmt, ...)
{
va_list args;
va_start(args,fmt);
vsnprintf(ErrorBuffer,sizeof(ErrorBuffer),fmt,args);
va_end(args);
pr_warn("(device %s): %s(): %s\n", sb->s_id,
function,ErrorBuffer);
}
bool
affs_nofilenametruncate(const struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
return AFFS_SB(inode->i_sb)->s_flags & SF_NO_TRUNCATE;
}
/* Check if the name is valid for a affs object. */
int
affs_check_name(const unsigned char *name, int len, bool notruncate)
{
int i;
if (len > 30) {
if (notruncate)
return -ENAMETOOLONG;
else
len = 30;
}
for (i = 0; i < len; i++) {
if (name[i] < ' ' || name[i] == ':'
|| (name[i] > 0x7e && name[i] < 0xa0))
return -EINVAL;
}
return 0;
}
/* This function copies name to bstr, with at most 30
* characters length. The bstr will be prepended by
* a length byte.
* NOTE: The name will must be already checked by
* affs_check_name()!
*/
int
affs_copy_name(unsigned char *bstr, struct dentry *dentry)
{
int len = min(dentry->d_name.len, 30u);
*bstr++ = len;
memcpy(bstr, dentry->d_name.name, len);
return len;
}