// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2000-2001 Christoph Hellwig.
 * Copyright (c) 2016 Krzysztof Blaszkowski
 */

/*
 * Veritas filesystem driver - inode routines.
 */
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/pagemap.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/namei.h>

#include "vxfs.h"
#include "vxfs_inode.h"
#include "vxfs_extern.h"


#ifdef DIAGNOSTIC
/*
 * Dump inode contents (partially).
 */
void
vxfs_dumpi(struct vxfs_inode_info *vip, ino_t ino)
{
        printk(KERN_DEBUG "\n\n");
        if (ino)
                printk(KERN_DEBUG "dumping vxfs inode %ld\n", ino);
        else
                printk(KERN_DEBUG "dumping unknown vxfs inode\n");

        printk(KERN_DEBUG "---------------------------\n");
        printk(KERN_DEBUG "mode is %x\n", vip->vii_mode);
        printk(KERN_DEBUG "nlink:%u, uid:%u, gid:%u\n",
                        vip->vii_nlink, vip->vii_uid, vip->vii_gid);
        printk(KERN_DEBUG "size:%Lx, blocks:%u\n",
                        vip->vii_size, vip->vii_blocks);
        printk(KERN_DEBUG "orgtype:%u\n", vip->vii_orgtype);
}
#endif

/**
 * vxfs_transmod - mode for a VxFS inode
 * @vip:        VxFS inode
 *
 * Description:
 *  vxfs_transmod returns a Linux mode_t for a given
 *  VxFS inode structure.
 */
static __inline__ umode_t
vxfs_transmod(struct vxfs_inode_info *vip)
{
        umode_t                 ret = vip->vii_mode & ~VXFS_TYPE_MASK;

        if (VXFS_ISFIFO(vip))
                ret |= S_IFIFO;
        if (VXFS_ISCHR(vip))
                ret |= S_IFCHR;
        if (VXFS_ISDIR(vip))
                ret |= S_IFDIR;
        if (VXFS_ISBLK(vip))
                ret |= S_IFBLK;
        if (VXFS_ISLNK(vip))
                ret |= S_IFLNK;
        if (VXFS_ISREG(vip))
                ret |= S_IFREG;
        if (VXFS_ISSOC(vip))
                ret |= S_IFSOCK;

        return (ret);
}

static inline void dip2vip_cpy(struct vxfs_sb_info *sbi,
                struct vxfs_inode_info *vip, struct vxfs_dinode *dip)
{
        struct inode *inode = &vip->vfs_inode;

        vip->vii_mode = fs32_to_cpu(sbi, dip->vdi_mode);
        vip->vii_nlink = fs32_to_cpu(sbi, dip->vdi_nlink);
        vip->vii_uid = fs32_to_cpu(sbi, dip->vdi_uid);
        vip->vii_gid = fs32_to_cpu(sbi, dip->vdi_gid);
        vip->vii_size = fs64_to_cpu(sbi, dip->vdi_size);
        vip->vii_atime = fs32_to_cpu(sbi, dip->vdi_atime);
        vip->vii_autime = fs32_to_cpu(sbi, dip->vdi_autime);
        vip->vii_mtime = fs32_to_cpu(sbi, dip->vdi_mtime);
        vip->vii_mutime = fs32_to_cpu(sbi, dip->vdi_mutime);
        vip->vii_ctime = fs32_to_cpu(sbi, dip->vdi_ctime);
        vip->vii_cutime = fs32_to_cpu(sbi, dip->vdi_cutime);
        vip->vii_orgtype = dip->vdi_orgtype;

        vip->vii_blocks = fs32_to_cpu(sbi, dip->vdi_blocks);
        vip->vii_gen = fs32_to_cpu(sbi, dip->vdi_gen);

        if (VXFS_ISDIR(vip))
                vip->vii_dotdot = fs32_to_cpu(sbi, dip->vdi_dotdot);
        else if (!VXFS_ISREG(vip) && !VXFS_ISLNK(vip))
                vip->vii_rdev = fs32_to_cpu(sbi, dip->vdi_rdev);

        /* don't endian swap the fields that differ by orgtype */
        memcpy(&vip->vii_org, &dip->vdi_org, sizeof(vip->vii_org));

        inode->i_mode = vxfs_transmod(vip);
        i_uid_write(inode, (uid_t)vip->vii_uid);
        i_gid_write(inode, (gid_t)vip->vii_gid);

        set_nlink(inode, vip->vii_nlink);
        inode->i_size = vip->vii_size;

        inode->i_atime.tv_sec = vip->vii_atime;
        inode->i_ctime.tv_sec = vip->vii_ctime;
        inode->i_mtime.tv_sec = vip->vii_mtime;
        inode->i_atime.tv_nsec = 0;
        inode->i_ctime.tv_nsec = 0;
        inode->i_mtime.tv_nsec = 0;

        inode->i_blocks = vip->vii_blocks;
        inode->i_generation = vip->vii_gen;
}

/**
 * vxfs_blkiget - find inode based on extent #
 * @sbp:        superblock of the filesystem we search in
 * @extent:     number of the extent to search
 * @ino:        inode number to search
 *
 * Description:
 *  vxfs_blkiget searches inode @ino in the filesystem described by
 *  @sbp in the extent @extent.
 *  Returns the matching VxFS inode on success, else a NULL pointer.
 *
 * NOTE:
 *  While __vxfs_iget uses the pagecache vxfs_blkiget uses the
 *  buffercache.  This function should not be used outside the
 *  read_super() method, otherwise the data may be incoherent.
 */
struct inode *
vxfs_blkiget(struct super_block *sbp, u_long extent, ino_t ino)
{
        struct buffer_head              *bp;
        struct inode                    *inode;
        u_long                          block, offset;

        inode = new_inode(sbp);
        if (!inode)
                return NULL;
        inode->i_ino = get_next_ino();

        block = extent + ((ino * VXFS_ISIZE) / sbp->s_blocksize);
        offset = ((ino % (sbp->s_blocksize / VXFS_ISIZE)) * VXFS_ISIZE);
        bp = sb_bread(sbp, block);

        if (bp && buffer_mapped(bp)) {
                struct vxfs_inode_info  *vip = VXFS_INO(inode);
                struct vxfs_dinode      *dip;

                dip = (struct vxfs_dinode *)(bp->b_data + offset);
                dip2vip_cpy(VXFS_SBI(sbp), vip, dip);
                vip->vfs_inode.i_mapping->a_ops = &vxfs_aops;
#ifdef DIAGNOSTIC
                vxfs_dumpi(vip, ino);
#endif
                brelse(bp);
                return inode;
        }

        printk(KERN_WARNING "vxfs: unable to read block %ld\n", block);
        brelse(bp);
        iput(inode);
        return NULL;
}

/**
 * __vxfs_iget - generic find inode facility
 * @ilistp:             inode list
 * @vip:                VxFS inode to fill in
 * @ino:                inode number
 *
 * Description:
 *  Search the for inode number @ino in the filesystem
 *  described by @sbp.  Use the specified inode table (@ilistp).
 *  Returns the matching inode on success, else an error code.
 */
static int
__vxfs_iget(struct inode *ilistp, struct vxfs_inode_info *vip, ino_t ino)
{
        struct page                     *pp;
        u_long                          offset;

        offset = (ino % (PAGE_SIZE / VXFS_ISIZE)) * VXFS_ISIZE;
        pp = vxfs_get_page(ilistp->i_mapping, ino * VXFS_ISIZE / PAGE_SIZE);

        if (!IS_ERR(pp)) {
                struct vxfs_dinode      *dip;
                caddr_t                 kaddr = (char *)page_address(pp);

                dip = (struct vxfs_dinode *)(kaddr + offset);
                dip2vip_cpy(VXFS_SBI(ilistp->i_sb), vip, dip);
                vip->vfs_inode.i_mapping->a_ops = &vxfs_aops;
#ifdef DIAGNOSTIC
                vxfs_dumpi(vip, ino);
#endif
                vxfs_put_page(pp);
                return 0;
        }

        printk(KERN_WARNING "vxfs: error on page 0x%p for inode %ld\n",
                pp, (unsigned long)ino);
        return PTR_ERR(pp);
}

/**
 * vxfs_stiget - find inode using the structural inode list
 * @sbp:        VFS superblock
 * @ino:        inode #
 *
 * Description:
 *  Find inode @ino in the filesystem described by @sbp using
 *  the structural inode list.
 *  Returns the matching inode on success, else a NULL pointer.
 */
struct inode *
vxfs_stiget(struct super_block *sbp, ino_t ino)
{
        struct inode *inode;
        int error;

        inode = new_inode(sbp);
        if (!inode)
                return NULL;
        inode->i_ino = get_next_ino();

        error = __vxfs_iget(VXFS_SBI(sbp)->vsi_stilist, VXFS_INO(inode), ino);
        if (error) {
                iput(inode);
                return NULL;
        }

        return inode;
}

/**
 * vxfs_iget - get an inode
 * @sbp:        the superblock to get the inode for
 * @ino:        the number of the inode to get
 *
 * Description:
 *  vxfs_read_inode creates an inode, reads the disk inode for @ino and fills
 *  in all relevant fields in the new inode.
 */
struct inode *
vxfs_iget(struct super_block *sbp, ino_t ino)
{
        struct vxfs_inode_info          *vip;
        const struct address_space_operations   *aops;
        struct inode *ip;
        int error;

        ip = iget_locked(sbp, ino);
        if (!ip)
                return ERR_PTR(-ENOMEM);
        if (!(ip->i_state & I_NEW))
                return ip;

        vip = VXFS_INO(ip);
        error = __vxfs_iget(VXFS_SBI(sbp)->vsi_ilist, vip, ino);
        if (error) {
                iget_failed(ip);
                return ERR_PTR(error);
        }

        if (VXFS_ISIMMED(vip))
                aops = &vxfs_immed_aops;
        else
                aops = &vxfs_aops;

        if (S_ISREG(ip->i_mode)) {
                ip->i_fop = &generic_ro_fops;
                ip->i_mapping->a_ops = aops;
        } else if (S_ISDIR(ip->i_mode)) {
                ip->i_op = &vxfs_dir_inode_ops;
                ip->i_fop = &vxfs_dir_operations;
                ip->i_mapping->a_ops = aops;
        } else if (S_ISLNK(ip->i_mode)) {
                if (!VXFS_ISIMMED(vip)) {
                        ip->i_op = &page_symlink_inode_operations;
                        inode_nohighmem(ip);
                        ip->i_mapping->a_ops = &vxfs_aops;
                } else {
                        ip->i_op = &simple_symlink_inode_operations;
                        ip->i_link = vip->vii_immed.vi_immed;
                        nd_terminate_link(ip->i_link, ip->i_size,
                                          sizeof(vip->vii_immed.vi_immed) - 1);
                }
        } else
                init_special_inode(ip, ip->i_mode, old_decode_dev(vip->vii_rdev));

        unlock_new_inode(ip);
        return ip;
}

/**
 * vxfs_evict_inode - remove inode from main memory
 * @ip:         inode to discard.
 *
 * Description:
 *  vxfs_evict_inode() is called on the final iput and frees the private
 *  inode area.
 */
void
vxfs_evict_inode(struct inode *ip)
{
        truncate_inode_pages_final(&ip->i_data);
        clear_inode(ip);
}