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/*

 *  linux/fs/sysv/fsync.c

 *

 *  minix/fsync.c

 *  Copyright (C) 1991, 1992  Linus Torvalds

 *  Copyright (C) 1993  Stephen Tweedie (sct@dcs.ed.ac.uk)

 *

 *  coh/fsync.c

 *  Copyright (C) 1993  Pascal Haible, Bruno Haible

 *

 *  sysv/fsync.c

 *  Copyright (C) 1993  Bruno Haible

 *

 *  SystemV/Coherent fsync primitive

 */

#include <linux/errno.h>

#include <linux/stat.h>

#include <linux/fs.h>

#include <linux/sysv_fs.h>

/* return values: 0 means OK/done, 1 means redo, -1 means I/O error. */

/* Sync one block. The block number is

 * from_coh_ulong(*blockp) if convert=1, *blockp if convert=0.

 */

static int sync_block (struct inode * inode, unsigned long * blockp, int convert, int wait)

{

        struct buffer_head * bh;

        unsigned long tmp, block;

        struct super_block * sb;

        block = tmp = *blockp;

        if (convert)

                block = from_coh_ulong(block);

        if (!block)

                return 0;

        sb = inode->i_sb;

        bh = sv_get_hash_table(sb, inode->i_dev, block);

        if (!bh)

                return 0;

        if (*blockp != tmp) {

                brelse (bh);

                return 1;

        }

        if (wait && buffer_req(bh) && !buffer_uptodate(bh)) {

                brelse(bh);

                return -1;

        }

        if (wait || !buffer_uptodate(bh) || !buffer_dirty(bh)) {

                brelse(bh);

                return 0;

        }

        ll_rw_block(WRITE, 1, &bh);

        bh->b_count--;

        return 0;

}

/* Sync one block full of indirect pointers and read it because we'll need it. */

static int sync_iblock (struct inode * inode, unsigned long * iblockp, int convert,

                        struct buffer_head * *bh, int wait)

{

        int rc;

        unsigned long tmp, block;

        *bh = NULL;

        block = tmp = *iblockp;

        if (convert)

                block = from_coh_ulong(block);

        if (!block)

                return 0;

        rc = sync_block (inode, iblockp, convert, wait);

        if (rc)

                return rc;

        *bh = sv_bread(inode->i_sb, inode->i_dev, block);

        if (tmp != *iblockp) {

                brelse(*bh);

                *bh = NULL;

                return 1;

        }

        if (!*bh)

                return -1;

        return 0;

}

static int sync_direct(struct inode *inode, int wait)

{

        int i;

        int rc, err = 0;

        for (i = 0; i < 10; i++) {

                rc = sync_block (inode, inode->u.sysv_i.i_data + i, 0, wait);

                if (rc > 0)

                        break;

                if (rc)

                        err = rc;

        }

        return err;

}

static int sync_indirect(struct inode *inode, unsigned long *iblockp, int convert, int wait)

{

        int i;

        struct buffer_head * ind_bh;

        int rc, err = 0;

        struct super_block * sb;

        rc = sync_iblock (inode, iblockp, convert, &ind_bh, wait);

        if (rc || !ind_bh)

                return rc;

        sb = inode->i_sb;

        for (i = 0; i < sb->sv_ind_per_block; i++) {

                rc = sync_block (inode,

                                 ((unsigned long *) ind_bh->b_data) + i, sb->sv_convert,

                                 wait);

                if (rc > 0)

                        break;

                if (rc)

                        err = rc;

        }

        brelse(ind_bh);

        return err;

}

static int sync_dindirect(struct inode *inode, unsigned long *diblockp, int convert,

                          int wait)

{

        int i;

        struct buffer_head * dind_bh;

        int rc, err = 0;

        struct super_block * sb;

        rc = sync_iblock (inode, diblockp, convert, &dind_bh, wait);

        if (rc || !dind_bh)

                return rc;

        sb = inode->i_sb;

        for (i = 0; i < sb->sv_ind_per_block; i++) {

                rc = sync_indirect (inode,

                                    ((unsigned long *) dind_bh->b_data) + i, sb->sv_convert,

                                    wait);

                if (rc > 0)

                        break;

                if (rc)

                        err = rc;

        }

        brelse(dind_bh);

        return err;

}

static int sync_tindirect(struct inode *inode, unsigned long *tiblockp, int convert,

                          int wait)

{

        int i;

        struct buffer_head * tind_bh;

        int rc, err = 0;

        struct super_block * sb;

        rc = sync_iblock (inode, tiblockp, convert, &tind_bh, wait);

        if (rc || !tind_bh)

                return rc;

        sb = inode->i_sb;

        for (i = 0; i < sb->sv_ind_per_block; i++) {

                rc = sync_dindirect (inode,

                                     ((unsigned long *) tind_bh->b_data) + i, sb->sv_convert,

                                     wait);

                if (rc > 0)

                        break;

                if (rc)

                        err = rc;

        }

        brelse(tind_bh);

        return err;

}

int sysv_sync_file(struct inode * inode, struct file * file)

{

        int wait, err = 0;

        if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||

             S_ISLNK(inode->i_mode)))

                return -EINVAL;

        for (wait=0; wait<=1; wait++) {

                err |= sync_direct(inode, wait);

                err |= sync_indirect(inode, inode->u.sysv_i.i_data+10, 0, wait);

                err |= sync_dindirect(inode, inode->u.sysv_i.i_data+11, 0, wait);

                err |= sync_tindirect(inode, inode->u.sysv_i.i_data+12, 0, wait);

        }

        err |= sysv_sync_inode (inode);

        return (err < 0) ? -EIO : 0;

}