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/*
* linux/fs/ext2/fsync.c
*
* Copyright (C) 1993 Stephen Tweedie (sct@dcs.ed.ac.uk)
* from
* Copyright (C) 1992 Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
* from
* linux/fs/minix/truncate.c Copyright (C) 1991, 1992 Linus Torvalds
*
* ext2fs fsync primitive
*
* Big-endian to little-endian byte-swapping/bitmaps by
* David S. Miller (davem@caip.rutgers.edu), 1995
*
* Removed unnecessary code duplication for little endian machines
* and excessive __inline__s.
* Andi Kleen, 1997
*
* Major simplications and cleanup - we only need to do the metadata, because
* we can depend on generic_block_fdatasync() to sync the data blocks.
*/
#include <linux/fs.h>
#include <linux/locks.h>
#include <linux/smp_lock.h>
#define blocksize (EXT2_BLOCK_SIZE(inode->i_sb))
#define addr_per_block (EXT2_ADDR_PER_BLOCK(inode->i_sb))
static int sync_indirect(struct inode * inode, u32 * block, int wait)
{
struct buffer_head * bh;
if (!*block)
return 0;
bh = get_hash_table(inode->i_dev, le32_to_cpu(*block), blocksize);
if (!bh)
return 0;
if (wait && buffer_req(bh) && !buffer_uptodate(bh)) {
/* There can be a parallell read(2) that started read-I/O
on the buffer so we can't assume that there's been
an I/O error without first waiting I/O completation. */
wait_on_buffer(bh);
if (!buffer_uptodate(bh))
{
brelse (bh);
return -1;
}
}
if (wait || !buffer_uptodate(bh) || !buffer_dirty(bh)) {
if (wait)
/* when we return from fsync all the blocks
must be _just_ stored on disk */
wait_on_buffer(bh);
brelse(bh);
return 0;
}
ll_rw_block(WRITE, 1, &bh);
atomic_dec(&bh->b_count);
return 0;
}
static int sync_iblock(struct inode * inode, u32 * iblock,
struct buffer_head ** bh, int wait)
{
int rc, tmp;
*bh = NULL;
tmp = le32_to_cpu(*iblock);
if (!tmp)
return 0;
rc = sync_indirect(inode, iblock, wait);
if (rc)
return rc;
*bh = bread(inode->i_dev, tmp, blocksize);
if (!*bh)
return -1;
return 0;
}
static int sync_dindirect(struct inode * inode, u32 * diblock, int wait)
{
int i;
struct buffer_head * dind_bh;
int rc, err = 0;
rc = sync_iblock(inode, diblock, &dind_bh, wait);
if (rc || !dind_bh)
return rc;
for (i = 0; i < addr_per_block; i++) {
rc = sync_indirect(inode, ((u32 *) dind_bh->b_data) + i, wait);
if (rc)
err = rc;
}
brelse(dind_bh);
return err;
}
static int sync_tindirect(struct inode * inode, u32 * tiblock, int wait)
{
int i;
struct buffer_head * tind_bh;
int rc, err = 0;
rc = sync_iblock(inode, tiblock, &tind_bh, wait);
if (rc || !tind_bh)
return rc;
for (i = 0; i < addr_per_block; i++) {
rc = sync_dindirect(inode, ((u32 *) tind_bh->b_data) + i, wait);
if (rc)
err = rc;
}
brelse(tind_bh);
return err;
}
/*
* File may be NULL when we are called. Perhaps we shouldn't
* even pass file to fsync ?
*/
int ext2_sync_file(struct file * file, struct dentry *dentry)
{
int wait, err = 0;
struct inode *inode = dentry->d_inode;
lock_kernel();
if (S_ISLNK(inode->i_mode) && !(inode->i_blocks))
/*
* Don't sync fast links!
*/
goto skip;
err = generic_buffer_fdatasync(inode, 0, ~0UL);
for (wait=0; wait<=1; wait++)
{
err |= sync_indirect(inode,
inode->u.ext2_i.i_data+EXT2_IND_BLOCK,
wait);
err |= sync_dindirect(inode,
inode->u.ext2_i.i_data+EXT2_DIND_BLOCK,
wait);
err |= sync_tindirect(inode,
inode->u.ext2_i.i_data+EXT2_TIND_BLOCK,
wait);
}
skip:
err |= ext2_sync_inode (inode);
unlock_kernel();
return err ? -EIO : 0;
}
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