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/*

 *  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 dentry *dentry, u32 entry_ino)

{

        struct inode *inode = dentry->d_inode;

        void *data = dentry->d_fsdata;

        struct list_head *head, *next;

        spin_lock(&dcache_lock);

        head = &inode->i_dentry;

        next = head->next;

        while (next != head) {

                dentry = list_entry(next, struct dentry, d_alias);

                if (entry_ino == (u32)(long)dentry->d_fsdata) {

                        dentry->d_fsdata = data;

                        break;

                }

                next = next->next;

        }

        spin_unlock(&dcache_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 = iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent));

                if (!dir)

                        goto done;

                affs_lock_dir(dir);

                affs_fix_dcache(dentry, link_ino);

                retval = affs_remove_hash(dir, link_bh);

                if (retval)

                        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)

                        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)

                                        inode->i_nlink = 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

                inode->i_nlink = 0;

        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);

}

mode_t

prot_to_mode(u32 prot)

{

        int 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;

        mode_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);

}

/* Check if the name is valid for a affs object. */

int

affs_check_name(const unsigned char *name, int len)

{

        int      i;

        if (len > 30)

#ifdef AFFS_NO_TRUNCATE

                return -ENAMETOOLONG;

#else

                len = 30;

#endif

        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;

}