/*
* Do I/O of a whole region of data, whether or not it's block-aligned.
*/
static
int
sfs_io(struct sfs_vnode *sv, struct uio *uio)
{
u_int32_t blkoff;
u_int32_t nblocks, i;
int result = 0;
u_int32_t extraresid = 0;
/*
* If reading, check for EOF. If we can read a partial area,
* remember how much extra there was in EXTRARESID so we can
* add it back to uio_resid at the end.
*/
if (uio->uio_rw == UIO_READ) {
off_t size = sv->sv_i.sfi_size;
off_t endpos = uio->uio_offset + uio->uio_resid;
if (uio->uio_offset >= size) {
/* At or past EOF - just return */
return 0;
}
if (endpos > size) {
extraresid = endpos - size;
assert(uio->uio_resid > extraresid);
uio->uio_resid -= extraresid;
}
}
/*
* First, do any leading partial block.
*/
blkoff = uio->uio_offset % SFS_BLOCKSIZE;
if (blkoff != 0) {
/* Number of bytes at beginning of block to skip */
u_int32_t skip = blkoff;
/* Number of bytes to read/write after that point */
u_int32_t len = SFS_BLOCKSIZE - blkoff;
/* ...which might be less than the rest of the block */
if (len > uio->uio_resid) {
len = uio->uio_resid;
}
/* Call sfs_partialio() to do it. */
result = sfs_partialio(sv, uio, skip, len);
if (result) {
goto out;
}
}
/* If we're done, quit. */
if (uio->uio_resid==0) {
goto out;
}
/*
* Now we should be block-aligned. Do the remaining whole blocks.
*/
assert(uio->uio_offset % SFS_BLOCKSIZE == 0);
nblocks = uio->uio_resid / SFS_BLOCKSIZE;
for (i=0; i<nblocks; i++) {
result = sfs_blockio(sv, uio);
if (result) {
goto out;
}
}
/*
* Now do any remaining partial block at the end.
*/
assert(uio->uio_resid < SFS_BLOCKSIZE);
if (uio->uio_resid > 0) {
result = sfs_partialio(sv, uio, 0, uio->uio_resid);
if (result) {
goto out;
}
}
out:
/* If writing, adjust file length */
if (uio->uio_rw == UIO_WRITE &&
uio->uio_offset > (off_t)sv->sv_i.sfi_size) {
sv->sv_i.sfi_size = uio->uio_offset;
sv->sv_dirty = 1;
}
/* Add in any extra amount we couldn't read because of EOF */
uio->uio_resid += extraresid;
/* Done */
return result;
}
/*
* Do I/O of a whole region of data, whether or not it's block-aligned.
*
* Locking: must hold vnode lock. May get/release sfs_freemaplock.
*
* Requires up to 3 buffers.
*/
int
sfs_io(struct sfs_vnode *sv, struct uio *uio)
{
uint32_t blkoff;
uint32_t nblocks, i;
int result = 0;
uint32_t origresid, extraresid = 0;
struct sfs_dinode *inodeptr;
KASSERT(lock_do_i_hold(sv->sv_lock));
origresid = uio->uio_resid;
result = sfs_dinode_load(sv);
if (result) {
return result;
}
inodeptr = sfs_dinode_map(sv);
/*
* If reading, check for EOF. If we can read a partial area,
* remember how much extra there was in EXTRARESID so we can
* add it back to uio_resid at the end.
*/
if (uio->uio_rw == UIO_READ) {
off_t size, endpos;
size = inodeptr->sfi_size;
endpos = uio->uio_offset + uio->uio_resid;
if (uio->uio_offset >= size) {
/* At or past EOF - just return */
sfs_dinode_unload(sv);
return 0;
}
if (endpos > size) {
extraresid = endpos - size;
KASSERT(uio->uio_resid > extraresid);
uio->uio_resid -= extraresid;
}
}
/*
* First, do any leading partial block.
*/
blkoff = uio->uio_offset % SFS_BLOCKSIZE;
if (blkoff != 0) {
/* Number of bytes at beginning of block to skip */
uint32_t skip = blkoff;
/* Number of bytes to read/write after that point */
uint32_t len = SFS_BLOCKSIZE - blkoff;
/* ...which might be less than the rest of the block */
if (len > uio->uio_resid) {
len = uio->uio_resid;
}
/* Call sfs_partialio() to do it. */
result = sfs_partialio(sv, uio, skip, len);
if (result) {
goto out;
}
}
/* If we're done, quit. */
if (uio->uio_resid==0) {
goto out;
}
/*
* Now we should be block-aligned. Do the remaining whole blocks.
*/
KASSERT(uio->uio_offset % SFS_BLOCKSIZE == 0);
nblocks = uio->uio_resid / SFS_BLOCKSIZE;
for (i=0; i<nblocks; i++) {
result = sfs_blockio(sv, uio);
if (result) {
goto out;
}
}
/*
* Now do any remaining partial block at the end.
*/
KASSERT(uio->uio_resid < SFS_BLOCKSIZE);
if (uio->uio_resid > 0) {
result = sfs_partialio(sv, uio, 0, uio->uio_resid);
if (result) {
goto out;
}
}
out:
/* If writing and we did anything, adjust file length */
if (uio->uio_resid != origresid &&
uio->uio_rw == UIO_WRITE &&
uio->uio_offset > (off_t)inodeptr->sfi_size) {
sfs_jphys_write_wrapper(sv->sv_absvn.vn_fs->fs_data, NULL,
jentry_resize( sv->sv_ino, // disk_addr
inodeptr->sfi_size, // old_size
uio->uio_offset)); // new_size
inodeptr->sfi_size = uio->uio_offset;
sfs_dinode_mark_dirty(sv);
}
sfs_dinode_unload(sv);
/* Add in any extra amount we couldn't read because of EOF */
uio->uio_resid += extraresid;
/* Done */
return result;
}
