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/* -*- mode: c; c-basic-offset: 8; -*-
* vim : noexpandtab sw = 8 ts = 8 sts = 0 :
*
* io . c
*
* Buffer cache handling
*
* Copyright ( C ) 2002 , 2004 Oracle . All rights reserved .
*
* This program is free software ; you can redistribute it and / or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation ; either
* version 2 of the License , or ( at your option ) any later version .
*
* This program is distributed in the hope that it will be useful ,
* but WITHOUT ANY WARRANTY ; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE . See the GNU
* General Public License for more details .
*
* You should have received a copy of the GNU General Public
* License along with this program ; if not , write to the
* Free Software Foundation , Inc . , 59 Temple Place - Suite 330 ,
* Boston , MA 021110 - 1307 , USA .
*/
# include <linux/fs.h>
# include <linux/types.h>
# include <linux/slab.h>
# include <linux/highmem.h>
# include <cluster/masklog.h>
# include "ocfs2.h"
# include "alloc.h"
# include "inode.h"
# include "journal.h"
# include "uptodate.h"
# include "buffer_head_io.h"
int ocfs2_write_block ( struct ocfs2_super * osb , struct buffer_head * bh ,
struct inode * inode )
{
int ret = 0 ;
mlog_entry ( " (bh->b_blocknr = %llu, inode=%p) \n " ,
( unsigned long long ) bh - > b_blocknr , inode ) ;
BUG_ON ( bh - > b_blocknr < OCFS2_SUPER_BLOCK_BLKNO ) ;
BUG_ON ( buffer_jbd ( bh ) ) ;
/* No need to check for a soft readonly file system here. non
* journalled writes are only ever done on system files which
* can get modified during recovery even if read - only . */
if ( ocfs2_is_hard_readonly ( osb ) ) {
ret = - EROFS ;
goto out ;
}
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mutex_lock ( & OCFS2_I ( inode ) - > ip_io_mutex ) ;
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lock_buffer ( bh ) ;
set_buffer_uptodate ( bh ) ;
/* remove from dirty list before I/O. */
clear_buffer_dirty ( bh ) ;
get_bh ( bh ) ; /* for end_buffer_write_sync() */
bh - > b_end_io = end_buffer_write_sync ;
submit_bh ( WRITE , bh ) ;
wait_on_buffer ( bh ) ;
if ( buffer_uptodate ( bh ) ) {
ocfs2_set_buffer_uptodate ( inode , bh ) ;
} else {
/* We don't need to remove the clustered uptodate
* information for this bh as it ' s not marked locally
* uptodate . */
ret = - EIO ;
brelse ( bh ) ;
}
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mutex_unlock ( & OCFS2_I ( inode ) - > ip_io_mutex ) ;
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out :
mlog_exit ( ret ) ;
return ret ;
}
int ocfs2_read_blocks ( struct ocfs2_super * osb , u64 block , int nr ,
struct buffer_head * bhs [ ] , int flags ,
struct inode * inode )
{
int status = 0 ;
struct super_block * sb ;
int i , ignore_cache = 0 ;
struct buffer_head * bh ;
mlog_entry ( " (block=(% " MLFu64 " ), nr=(%d), flags=%d, inode=%p) \n " ,
block , nr , flags , inode ) ;
if ( osb = = NULL | | osb - > sb = = NULL | | bhs = = NULL ) {
status = - EINVAL ;
mlog_errno ( status ) ;
goto bail ;
}
if ( nr < 0 ) {
mlog ( ML_ERROR , " asked to read %d blocks! \n " , nr ) ;
status = - EINVAL ;
mlog_errno ( status ) ;
goto bail ;
}
if ( nr = = 0 ) {
mlog ( ML_BH_IO , " No buffers will be read! \n " ) ;
status = 0 ;
goto bail ;
}
sb = osb - > sb ;
if ( flags & OCFS2_BH_CACHED & & ! inode )
flags & = ~ OCFS2_BH_CACHED ;
if ( inode )
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mutex_lock ( & OCFS2_I ( inode ) - > ip_io_mutex ) ;
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for ( i = 0 ; i < nr ; i + + ) {
if ( bhs [ i ] = = NULL ) {
bhs [ i ] = sb_getblk ( sb , block + + ) ;
if ( bhs [ i ] = = NULL ) {
if ( inode )
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mutex_unlock ( & OCFS2_I ( inode ) - > ip_io_mutex ) ;
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status = - EIO ;
mlog_errno ( status ) ;
goto bail ;
}
}
bh = bhs [ i ] ;
ignore_cache = 0 ;
if ( flags & OCFS2_BH_CACHED & &
! ocfs2_buffer_uptodate ( inode , bh ) ) {
mlog ( ML_UPTODATE ,
" bh (%llu), inode % " MLFu64 " not uptodate \n " ,
( unsigned long long ) bh - > b_blocknr ,
OCFS2_I ( inode ) - > ip_blkno ) ;
ignore_cache = 1 ;
}
/* XXX: Can we ever get this and *not* have the cached
* flag set ? */
if ( buffer_jbd ( bh ) ) {
if ( ! ( flags & OCFS2_BH_CACHED ) | | ignore_cache )
mlog ( ML_BH_IO , " trying to sync read a jbd "
" managed bh (blocknr = %llu) \n " ,
( unsigned long long ) bh - > b_blocknr ) ;
continue ;
}
if ( ! ( flags & OCFS2_BH_CACHED ) | | ignore_cache ) {
if ( buffer_dirty ( bh ) ) {
/* This should probably be a BUG, or
* at least return an error . */
mlog ( ML_BH_IO , " asking me to sync read a dirty "
" buffer! (blocknr = %llu) \n " ,
( unsigned long long ) bh - > b_blocknr ) ;
continue ;
}
lock_buffer ( bh ) ;
if ( buffer_jbd ( bh ) ) {
# ifdef CATCH_BH_JBD_RACES
mlog ( ML_ERROR , " block %llu had the JBD bit set "
" while I was in lock_buffer! " ,
( unsigned long long ) bh - > b_blocknr ) ;
BUG ( ) ;
# else
unlock_buffer ( bh ) ;
continue ;
# endif
}
clear_buffer_uptodate ( bh ) ;
get_bh ( bh ) ; /* for end_buffer_read_sync() */
bh - > b_end_io = end_buffer_read_sync ;
if ( flags & OCFS2_BH_READAHEAD )
submit_bh ( READA , bh ) ;
else
submit_bh ( READ , bh ) ;
continue ;
}
}
status = 0 ;
for ( i = ( nr - 1 ) ; i > = 0 ; i - - ) {
bh = bhs [ i ] ;
/* We know this can't have changed as we hold the
* inode sem . Avoid doing any work on the bh if the
* journal has it . */
if ( ! buffer_jbd ( bh ) )
wait_on_buffer ( bh ) ;
if ( ! buffer_uptodate ( bh ) ) {
/* Status won't be cleared from here on out,
* so we can safely record this and loop back
* to cleanup the other buffers . Don ' t need to
* remove the clustered uptodate information
* for this bh as it ' s not marked locally
* uptodate . */
status = - EIO ;
brelse ( bh ) ;
bhs [ i ] = NULL ;
continue ;
}
if ( inode )
ocfs2_set_buffer_uptodate ( inode , bh ) ;
}
if ( inode )
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mutex_unlock ( & OCFS2_I ( inode ) - > ip_io_mutex ) ;
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mlog ( ML_BH_IO , " block=(% " MLFu64 " ), nr=(%d), cached=%s \n " , block , nr ,
( ! ( flags & OCFS2_BH_CACHED ) | | ignore_cache ) ? " no " : " yes " ) ;
bail :
mlog_exit ( status ) ;
return status ;
}