minix/servers/mfs/misc.c
Ben Gras 44f34e53d5 VFS: Implement REQ_BPEEK.
This commit introduces a new request type called REQ_BPEEK. It
requests minor device blocks from the FS.  Analogously to REQ_PEEK,
it requests the filesystem to get the requested blocks into its
cache, without actually copying the result anywhere.

Change-Id: If1d06645b0e17553a64b3167091e9d12efeb3d6f
2013-04-24 10:18:16 +00:00

86 lines
2.1 KiB
C

#include "fs.h"
#include <assert.h>
#include <minix/vfsif.h>
#include <minix/bdev.h>
#include "inode.h"
#include "clean.h"
/*===========================================================================*
* fs_sync *
*===========================================================================*/
int fs_sync()
{
/* Perform the sync() system call. Flush all the tables.
* The order in which the various tables are flushed is critical. The
* blocks must be flushed last, since rw_inode() leaves its results in
* the block cache.
*/
struct inode *rip;
assert(lmfs_nr_bufs() > 0);
/* Write all the dirty inodes to the disk. */
for(rip = &inode[0]; rip < &inode[NR_INODES]; rip++)
if(rip->i_count > 0 && IN_ISDIRTY(rip)) rw_inode(rip, WRITING);
/* Write all the dirty blocks to the disk. */
lmfs_flushall();
return(OK); /* sync() can't fail */
}
/*===========================================================================*
* fs_flush *
*===========================================================================*/
int fs_flush()
{
/* Flush the blocks of a device from the cache after writing any dirty blocks
* to disk.
*/
dev_t dev = (dev_t) fs_m_in.REQ_DEV;
if(dev == fs_dev) return(EBUSY);
lmfs_flushall();
lmfs_invalidate(dev);
return(OK);
}
/*===========================================================================*
* fs_new_driver *
*===========================================================================*/
int fs_new_driver(void)
{
/* Set a new driver endpoint for this device. */
dev_t dev;
cp_grant_id_t label_gid;
size_t label_len;
char label[sizeof(fs_dev_label)];
int r;
dev = (dev_t) fs_m_in.REQ_DEV;
label_gid = (cp_grant_id_t) fs_m_in.REQ_GRANT;
label_len = (size_t) fs_m_in.REQ_PATH_LEN;
if (label_len > sizeof(label))
return(EINVAL);
r = sys_safecopyfrom(fs_m_in.m_source, label_gid, (vir_bytes) 0,
(vir_bytes) label, label_len);
if (r != OK) {
printf("MFS: fs_new_driver safecopyfrom failed (%d)\n", r);
return(EINVAL);
}
bdev_driver(dev, label);
return(OK);
}
int fs_bpeek(void)
{
return lmfs_do_bpeek(&fs_m_in);
}