linux/fs/affs/amigaffs.c
Fabian Frederick 8ca577223f affs: add mount option to avoid filename truncates
Normal behavior for filenames exceeding specific filesystem limits is to
refuse operation.

AFFS standard name length being only 30 characters against 255 for usual
Linux filesystems, original implementation does filename truncate by
default with a define value AFFS_NO_TRUNCATE which can be enabled but
needs module compilation.

This patch adds 'nofilenametruncate' mount option so that user can
easily activate that feature and avoid a lot of problems (eg overwrite
files ...)

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:08 -07:00

520 lines
11 KiB
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"
extern struct timezone sys_tz;
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("AFFS: insert_hash(dir=%u, ino=%d)\n", (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("AFFS: remove_hash(dir=%d, ino=%d, hashval=%d)\n", (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("AFFS: remove_link(key=%ld)\n", 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("AFFS: remove_header(key=%ld)\n", 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);
printk(KERN_CRIT "AFFS error (device %s): %s(): %s\n", sb->s_id,
function,ErrorBuffer);
if (!(sb->s_flags & MS_RDONLY))
printk(KERN_WARNING "AFFS: 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);
printk(KERN_WARNING "AFFS warning (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;
}