int jfs_get_block(struct inode *ip, sector_t lblock,
struct buffer_head *bh_result, int create)
{
s64 lblock64 = lblock;
int rc = 0;
xad_t xad;
s64 xaddr;
int xflag;
s32 xlen = bh_result->b_size >> ip->i_blkbits;
/*
* Take appropriate lock on inode
*/
if (create)
IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
else
IREAD_LOCK(ip, RDWRLOCK_NORMAL);
if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
(!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
xaddr) {
if (xflag & XAD_NOTRECORDED) {
if (!create)
/*
* Allocated but not recorded, read treats
* this as a hole
*/
goto unlock;
#ifdef _JFS_4K
XADoffset(&xad, lblock64);
XADlength(&xad, xlen);
XADaddress(&xad, xaddr);
#else /* _JFS_4K */
/*
* As long as block size = 4K, this isn't a problem.
* We should mark the whole page not ABNR, but how
* will we know to mark the other blocks BH_New?
*/
BUG();
#endif /* _JFS_4K */
rc = extRecord(ip, &xad);
if (rc)
goto unlock;
set_buffer_new(bh_result);
}
map_bh(bh_result, ip->i_sb, xaddr);
bh_result->b_size = xlen << ip->i_blkbits;
goto unlock;
}
if (!create)
goto unlock;
/*
* Allocate a new block
*/
#ifdef _JFS_4K
if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
goto unlock;
rc = extAlloc(ip, xlen, lblock64, &xad, false);
if (rc)
goto unlock;
set_buffer_new(bh_result);
map_bh(bh_result, ip->i_sb, addressXAD(&xad));
bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
#else /* _JFS_4K */
/*
* We need to do whatever it takes to keep all but the last buffers
* in 4K pages - see jfs_write.c
*/
BUG();
#endif /* _JFS_4K */
unlock:
/*
* Release lock on inode
*/
if (create)
IWRITE_UNLOCK(ip);
else
IREAD_UNLOCK(ip);
return rc;
}
static int
jfs_get_blocks(struct inode *ip, sector_t lblock, unsigned long max_blocks,
struct buffer_head *bh_result, int create)
{
s64 lblock64 = lblock;
int no_size_check = 0;
int rc = 0;
int take_locks;
xad_t xad;
s64 xaddr;
int xflag;
s32 xlen;
/*
* If this is a special inode (imap, dmap) or directory,
* the lock should already be taken
*/
take_locks = ((JFS_IP(ip)->fileset != AGGREGATE_I) &&
!S_ISDIR(ip->i_mode));
/*
* Take appropriate lock on inode
*/
if (take_locks) {
if (create)
IWRITE_LOCK(ip);
else
IREAD_LOCK(ip);
}
/*
* A directory's "data" is the inode index table, but i_size is the
* size of the d-tree, so don't check the offset against i_size
*/
if (S_ISDIR(ip->i_mode))
no_size_check = 1;
if ((no_size_check ||
((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size)) &&
(xtLookup(ip, lblock64, max_blocks, &xflag, &xaddr, &xlen, no_size_check)
== 0) && xlen) {
if (xflag & XAD_NOTRECORDED) {
if (!create)
/*
* Allocated but not recorded, read treats
* this as a hole
*/
goto unlock;
#ifdef _JFS_4K
XADoffset(&xad, lblock64);
XADlength(&xad, xlen);
XADaddress(&xad, xaddr);
#else /* _JFS_4K */
/*
* As long as block size = 4K, this isn't a problem.
* We should mark the whole page not ABNR, but how
* will we know to mark the other blocks BH_New?
*/
BUG();
#endif /* _JFS_4K */
rc = extRecord(ip, &xad);
if (rc)
goto unlock;
set_buffer_new(bh_result);
}
map_bh(bh_result, ip->i_sb, xaddr);
bh_result->b_size = xlen << ip->i_blkbits;
goto unlock;
}
if (!create)
goto unlock;
/*
* Allocate a new block
*/
#ifdef _JFS_4K
if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
goto unlock;
rc = extAlloc(ip, max_blocks, lblock64, &xad, FALSE);
if (rc)
goto unlock;
set_buffer_new(bh_result);
map_bh(bh_result, ip->i_sb, addressXAD(&xad));
bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
#else /* _JFS_4K */
/*
* We need to do whatever it takes to keep all but the last buffers
* in 4K pages - see jfs_write.c
*/
BUG();
#endif /* _JFS_4K */
unlock:
/*
* Release lock on inode
*/
if (take_locks) {
if (create)
IWRITE_UNLOCK(ip);
else
IREAD_UNLOCK(ip);
}
return rc;
}