/*
* Write (overwrite) the directory entry in slot SLOT of a directory
* vnode.
*/
static
int
sfs_writedir(struct sfs_vnode *sv, struct sfs_dir *sd, int slot)
{
struct uio ku;
off_t actualpos;
int result;
/* Compute the actual position in the directory. */
assert(slot>=0);
actualpos = slot * sizeof(struct sfs_dir);
/* Set up a uio to do the write */
mk_kuio(&ku, sd, sizeof(struct sfs_dir), actualpos, UIO_WRITE);
/* do it */
result = sfs_io(sv, &ku);
if (result) {
return result;
}
/* Should not end up with a partial entry! */
if (ku.uio_resid > 0) {
panic("sfs: writedir: Short write (ino %u)\n", sv->sv_ino);
}
/* Done */
return 0;
}
/*
* Read the directory entry out of slot SLOT of a directory vnode.
* The "slot" is the index of the directory entry, starting at 0.
*/
static
int
sfs_readdir(struct sfs_vnode *sv, struct sfs_dir *sd, int slot)
{
struct uio ku;
off_t actualpos;
int result;
/* Compute the actual position in the directory to read. */
actualpos = slot * sizeof(struct sfs_dir);
/* Set up a uio to do the read */
mk_kuio(&ku, sd, sizeof(struct sfs_dir), actualpos, UIO_READ);
/* do it */
result = sfs_io(sv, &ku);
if (result) {
return result;
}
/* We should not hit EOF in the middle of a directory entry */
if (ku.uio_resid > 0) {
panic("sfs: readdir: Short entry (inode %u)\n", sv->sv_ino);
}
/* Done */
return 0;
}
/*
* Called for write(). sfs_io() does the work.
*/
static
int
sfs_write(struct vnode *v, struct uio *uio)
{
struct sfs_vnode *sv = v->vn_data;
assert(uio->uio_rw==UIO_WRITE);
return sfs_io(sv, uio);
}
/*
* Called for read(). sfs_io() does the work.
*/
static
int
sfs_read(struct vnode *v, struct uio *uio)
{
struct sfs_vnode *sv = v->vn_data;
assert(uio->uio_rw==UIO_READ);
return sfs_io(sv, uio);
}
/*
* Called for write(). sfs_io() does the work.
*/
static
int
sfs_write(struct vnode *v, struct uio *uio)
{
struct sfs_vnode *sv = v->vn_data;
int result;
KASSERT(uio->uio_rw==UIO_WRITE);
vfs_biglock_acquire();
result = sfs_io(sv, uio);
vfs_biglock_release();
return result;
}
/*
* Called for write(). sfs_io() does the work.
*
* Locking: gets/releases vnode lock.
*
* Requires up to 3 buffers.
*/
static
int
sfs_write(struct vnode *v, struct uio *uio)
{
struct sfs_vnode *sv = v->vn_data;
int result;
KASSERT(uio->uio_rw==UIO_WRITE);
lock_acquire(sv->sv_lock);
reserve_buffers(SFS_BLOCKSIZE);
result = sfs_io(sv, uio);
unreserve_buffers(SFS_BLOCKSIZE);
lock_release(sv->sv_lock);
return result;
}
// sfs_write - write file
static int
sfs_write(struct inode *node, struct iobuf *iob) {
return sfs_io(node, iob, 1);
}
// sfs_read - read file
static int
sfs_read(struct inode *node, struct iobuf *iob) {
return sfs_io(node, iob, 0);
}
