void parse_susp_rock_ridge_plcl(struct rrii_dir_record *dir, u32_t block) {
struct inode *rep_inode;
struct buf *bp;
struct iso9660_dir_record *dir_rec;
struct dir_extent extent;
struct inode_dir_entry dummy_dir_entry;
size_t dummy_offset = 0;
/* Check if inode wasn't already parsed. */
rep_inode = inode_cache_get(block);
if (rep_inode != NULL) {
rep_inode->i_refcount++;
dir->reparented_inode = rep_inode;
return;
}
/* Peek ahead to build extent for read_inode. */
if (lmfs_get_block(&bp, fs_dev, block, NORMAL) != OK)
return;
dir_rec = (struct iso9660_dir_record*)b_data(bp);
extent.location = block;
extent.length = dir_rec->data_length_l / v_pri.logical_block_size_l;
if (dir_rec->data_length_l % v_pri.logical_block_size_l)
extent.length++;
extent.next = NULL;
lmfs_put_block(bp);
memset(&dummy_dir_entry, 0, sizeof(struct inode_dir_entry));
read_inode(&dummy_dir_entry, &extent, &dummy_offset);
free(dummy_dir_entry.r_name);
dir->reparented_inode = dummy_dir_entry.i_node;
}
static struct buf* fetch_inode(struct dir_extent *extent, size_t *offset)
{
struct iso9660_dir_record *dir_rec;
struct buf *bp;
/*
* Directory entries aren't allowed to cross a logical block boundary in
* ISO 9660, so we keep searching until we find something or reach the
* end of the extent.
*/
bp = read_extent_block(extent, *offset / v_pri.logical_block_size_l);
while (bp != NULL) {
dir_rec = (struct iso9660_dir_record*)(b_data(bp) + *offset %
v_pri.logical_block_size_l);
if (dir_rec->length == 0) {
*offset -= *offset % v_pri.logical_block_size_l;
*offset += v_pri.logical_block_size_l;
}
else {
break;
}
lmfs_put_block(bp, FULL_DATA_BLOCK);
bp = read_extent_block(extent, *offset /
v_pri.logical_block_size_l);
}
return bp;
}
int read_inode(struct inode *i_node, struct dir_extent *extent, size_t offset,
size_t *new_offset)
{
struct iso9660_dir_record *dir_rec;
struct buf *bp;
/* Find inode. */
bp = fetch_inode(extent, &offset);
if (bp == NULL)
return EOF;
dir_rec = (struct iso9660_dir_record*)(b_data(bp) + offset %
v_pri.logical_block_size_l);
/* Parse basic ISO 9660 specs. */
if (check_dir_record(dir_rec,
offset % v_pri.logical_block_size_l) != OK) {
lmfs_put_block(bp, FULL_DATA_BLOCK);
return EINVAL;
}
memset(&i_node->i_stat, 0, sizeof(struct stat));
i_node->i_stat.st_ino = get_extent_absolute_block_id(extent,
offset / v_pri.logical_block_size_l) * v_pri.logical_block_size_l +
offset % v_pri.logical_block_size_l;
read_inode_iso9660(i_node, dir_rec);
/* Parse extensions. */
read_inode_susp(i_node, dir_rec, bp,
offset % v_pri.logical_block_size_l);
offset += dir_rec->length;
read_inode_extents(i_node, dir_rec, extent, &offset);
lmfs_put_block(bp, FULL_DATA_BLOCK);
if (new_offset != NULL)
*new_offset = offset;
return OK;
}
int
readblock(int b, int blocksize, u32_t seed, char *data)
{
struct buf *bp;
assert(blocksize == curblocksize);
if(!(bp = lmfs_get_block(MYDEV, b, NORMAL))) {
e(30);
return 0;
}
memcpy(data, bp->data, blocksize);
lmfs_put_block(bp, FULL_DATA_BLOCK);
return blocksize;
}
int
readblock(int b, int blocksize, u32_t seed, char *data)
{
struct buf *bp;
int r;
assert(blocksize == curblocksize);
if ((r = lmfs_get_block(&bp, MYDEV, b, NORMAL)) != 0) {
e(30);
return 0;
}
memcpy(data, bp->data, blocksize);
lmfs_put_block(bp);
return blocksize;
}
/*
* Prefetch up to "nblocks" blocks on "dev" starting from block number "block".
* Stop early when either the I/O request fills up or when a block is already
* found to be in the cache. The latter is likely to happen often, since this
* function is called before getting each block for reading. Prefetching is a
* strictly best-effort operation, and may fail silently.
* TODO: limit according to the number of available buffers.
*/
static void
block_prefetch(dev_t dev, block_t block, block_t nblocks)
{
struct buf *bp, *bufs[NR_IOREQS];
unsigned int count;
for (count = 0; count < nblocks; count++) {
bp = lmfs_get_block(dev, block + count, PREFETCH);
assert(bp != NULL);
if (lmfs_dev(bp) != NO_DEV) {
lmfs_put_block(bp, FULL_DATA_BLOCK);
break;
}
bufs[count] = bp;
}
if (count > 0)
lmfs_rw_scattered(dev, bufs, count, READING);
}
/*
* Perform block I/O, on "dev", starting from offset "pos", for a total of
* "bytes" bytes. Reading, writing, and peeking are highly similar, and thus,
* this function implements all of them. The "call" parameter indicates the
* call type (one of FSC_READ, FSC_WRITE, FSC_PEEK). For read and write calls,
* "data" will identify the user buffer to use; for peek calls, "data" is set
* to NULL. In all cases, this function returns the number of bytes
* successfully transferred, 0 on end-of-file conditions, and a negative error
* code if no bytes could be transferred due to an error. Dirty data is not
* flushed immediately, and thus, a successful write only indicates that the
* data have been taken in by the cache (for immediate I/O, a character device
* would have to be used, but MINIX3 no longer supports this), which may be
* follwed later by silent failures, including undetected end-of-file cases.
* In particular, write requests may or may not return 0 (EOF) immediately when
* writing at or beyond the block device's size. i Since block I/O takes place
* at block granularity, block-unaligned writes have to read a block from disk
* before updating it, and that is the only possible source of actual I/O
* errors for write calls.
* TODO: reconsider the buffering-only approach, or see if we can at least
* somehow throw accurate EOF errors without reading in each block first.
*/
ssize_t
lmfs_bio(dev_t dev, struct fsdriver_data * data, size_t bytes, off_t pos,
int call)
{
block_t block, blocks_left;
size_t block_size, off, block_off, chunk;
struct buf *bp;
int r, write, how;
if (dev == NO_DEV)
return EINVAL;
block_size = lmfs_fs_block_size();
write = (call == FSC_WRITE);
assert(block_size > 0);
/* FIXME: block_t is 32-bit, so we have to impose a limit here. */
if (pos < 0 || pos / block_size > UINT32_MAX || bytes > SSIZE_MAX)
return EINVAL;
off = 0;
block = pos / block_size;
block_off = (size_t)(pos % block_size);
blocks_left = howmany(block_off + bytes, block_size);
lmfs_reset_rdwt_err();
r = OK;
for (off = 0; off < bytes; off += chunk) {
chunk = block_size - block_off;
if (chunk > bytes - off)
chunk = bytes - off;
/*
* For read requests, help the block driver form larger I/O
* requests.
*/
if (!write)
block_prefetch(dev, block, blocks_left);
/*
* Do not read the block from disk if we will end up
* overwriting all of its contents.
*/
how = (write && chunk == block_size) ? NO_READ : NORMAL;
bp = lmfs_get_block(dev, block, how);
assert(bp);
r = lmfs_rdwt_err();
if (r == OK && data != NULL) {
assert(lmfs_dev(bp) != NO_DEV);
if (write) {
r = fsdriver_copyin(data, off,
(char *)bp->data + block_off, chunk);
/*
* Mark the block as dirty even if the copy
* failed, since the copy may in fact have
* succeeded partially. This is an interface
* issue that should be resolved at some point,
* but for now we do not want the cache to be
* desynchronized from the disk contents.
*/
lmfs_markdirty(bp);
} else
r = fsdriver_copyout(data, off,
(char *)bp->data + block_off, chunk);
}
lmfs_put_block(bp, FULL_DATA_BLOCK);
if (r != OK)
break;
block++;
block_off = 0;
blocks_left--;
}
/*
* If we were not able to do any I/O, return the error (or EOF, even
* for writes). Otherwise, return how many bytes we did manage to
* transfer.
*/
if (r != OK && off == 0)
return (r == END_OF_FILE) ? 0 : r;
return off;
}
ssize_t fs_read(ino_t ino_nr, struct fsdriver_data *data, size_t bytes,
off_t pos, int __unused call)
{
size_t off, chunk, block_size, cum_io;
off_t f_size;
struct inode *i_node;
struct buf *bp;
int r;
/* Try to get inode according to its index. */
if ((i_node = find_inode(ino_nr)) == NULL)
return EINVAL; /* No inode found. */
f_size = i_node->i_stat.st_size;
if (pos >= f_size)
return 0; /* EOF */
/* Limit the request to the remainder of the file size. */
if ((off_t)bytes > f_size - pos)
bytes = (size_t)(f_size - pos);
block_size = v_pri.logical_block_size_l;
cum_io = 0;
lmfs_reset_rdwt_err();
r = OK;
/* Split the transfer into chunks that don't span two blocks. */
while (bytes > 0) {
off = pos % block_size;
chunk = block_size - off;
if (chunk > bytes)
chunk = bytes;
/* Read 'chunk' bytes. */
bp = read_extent_block(i_node->extent, pos / block_size);
if (bp == NULL)
panic("bp not valid in rw_chunk; this can't happen");
r = fsdriver_copyout(data, cum_io, b_data(bp)+off, chunk);
lmfs_put_block(bp, FULL_DATA_BLOCK);
if (r != OK)
break; /* EOF reached. */
if (lmfs_rdwt_err() < 0)
break;
/* Update counters and pointers. */
bytes -= chunk; /* Bytes yet to be read. */
cum_io += chunk; /* Bytes read so far. */
pos += chunk; /* Position within the file. */
}
if (lmfs_rdwt_err() != OK)
r = lmfs_rdwt_err(); /* Check for disk error. */
if (lmfs_rdwt_err() == END_OF_FILE)
r = OK;
return (r == OK) ? cum_io : r;
}
/*===========================================================================*
* lmfs_rw_scattered *
*===========================================================================*/
void lmfs_rw_scattered(
dev_t dev, /* major-minor device number */
struct buf **bufq, /* pointer to array of buffers */
int bufqsize, /* number of buffers */
int rw_flag /* READING or WRITING */
)
{
/* Read or write scattered data from a device. */
register struct buf *bp;
int gap;
register int i;
register iovec_t *iop;
static iovec_t iovec[NR_IOREQS];
off_t pos;
int iov_per_block;
int start_in_use = bufs_in_use, start_bufqsize = bufqsize;
assert(bufqsize >= 0);
if(bufqsize == 0) return;
/* for READING, check all buffers on the list are obtained and held
* (count > 0)
*/
if (rw_flag == READING) {
for(i = 0; i < bufqsize; i++) {
assert(bufq[i] != NULL);
assert(bufq[i]->lmfs_count > 0);
}
/* therefore they are all 'in use' and must be at least this many */
assert(start_in_use >= start_bufqsize);
}
assert(dev != NO_DEV);
assert(fs_block_size > 0);
iov_per_block = roundup(fs_block_size, PAGE_SIZE) / PAGE_SIZE;
assert(iov_per_block < NR_IOREQS);
/* (Shell) sort buffers on lmfs_blocknr. */
gap = 1;
do
gap = 3 * gap + 1;
while (gap <= bufqsize);
while (gap != 1) {
int j;
gap /= 3;
for (j = gap; j < bufqsize; j++) {
for (i = j - gap;
i >= 0 && bufq[i]->lmfs_blocknr > bufq[i + gap]->lmfs_blocknr;
i -= gap) {
bp = bufq[i];
bufq[i] = bufq[i + gap];
bufq[i + gap] = bp;
}
}
}
/* Set up I/O vector and do I/O. The result of bdev I/O is OK if everything
* went fine, otherwise the error code for the first failed transfer.
*/
while (bufqsize > 0) {
int nblocks = 0, niovecs = 0;
int r;
for (iop = iovec; nblocks < bufqsize; nblocks++) {
int p;
vir_bytes vdata, blockrem;
bp = bufq[nblocks];
if (bp->lmfs_blocknr != (block_t) bufq[0]->lmfs_blocknr + nblocks)
break;
if(niovecs >= NR_IOREQS-iov_per_block) break;
vdata = (vir_bytes) bp->data;
blockrem = fs_block_size;
for(p = 0; p < iov_per_block; p++) {
vir_bytes chunk = blockrem < PAGE_SIZE ? blockrem : PAGE_SIZE;
iop->iov_addr = vdata;
iop->iov_size = chunk;
vdata += PAGE_SIZE;
blockrem -= chunk;
iop++;
niovecs++;
}
assert(p == iov_per_block);
assert(blockrem == 0);
}
assert(nblocks > 0);
assert(niovecs > 0);
pos = (off_t)bufq[0]->lmfs_blocknr * fs_block_size;
if (rw_flag == READING)
r = bdev_gather(dev, pos, iovec, niovecs, BDEV_NOFLAGS);
else
r = bdev_scatter(dev, pos, iovec, niovecs, BDEV_NOFLAGS);
/* Harvest the results. The driver may have returned an error, or it
* may have done less than what we asked for.
*/
if (r < 0) {
printf("fs cache: I/O error %d on device %d/%d, block %u\n",
r, major(dev), minor(dev), bufq[0]->lmfs_blocknr);
}
for (i = 0; i < nblocks; i++) {
bp = bufq[i];
if (r < (ssize_t) fs_block_size) {
/* Transfer failed. */
if (i == 0) {
bp->lmfs_dev = NO_DEV; /* Invalidate block */
}
break;
}
if (rw_flag == READING) {
bp->lmfs_dev = dev; /* validate block */
lmfs_put_block(bp, PARTIAL_DATA_BLOCK);
} else {
MARKCLEAN(bp);
}
r -= fs_block_size;
}
bufq += i;
bufqsize -= i;
if (rw_flag == READING) {
/* Don't bother reading more than the device is willing to
* give at this time. Don't forget to release those extras.
*/
while (bufqsize > 0) {
lmfs_put_block(*bufq++, PARTIAL_DATA_BLOCK);
bufqsize--;
}
}
if (rw_flag == WRITING && i == 0) {
/* We're not making progress, this means we might keep
* looping. Buffers remain dirty if un-written. Buffers are
* lost if invalidate()d or LRU-removed while dirty. This
* is better than keeping unwritable blocks around forever..
*/
break;
}
}
if(rw_flag == READING) {
assert(start_in_use >= start_bufqsize);
/* READING callers assume all bufs are released. */
assert(start_in_use - start_bufqsize == bufs_in_use);
}
}
/*===========================================================================*
* rw_scattered *
*===========================================================================*/
static void rw_scattered(
dev_t dev, /* major-minor device number */
struct buf **bufq, /* pointer to array of buffers */
unsigned int bufqsize, /* number of buffers */
int rw_flag /* READING or WRITING */
)
{
/* Read or write scattered data from a device. */
register struct buf *bp;
register iovec_t *iop;
static iovec_t iovec[NR_IOREQS];
off_t pos;
unsigned int i, iov_per_block;
#if !defined(NDEBUG)
unsigned int start_in_use = bufs_in_use, start_bufqsize = bufqsize;
#endif /* !defined(NDEBUG) */
if(bufqsize == 0) return;
#if !defined(NDEBUG)
/* for READING, check all buffers on the list are obtained and held
* (count > 0)
*/
if (rw_flag == READING) {
assert(bufqsize <= LMFS_MAX_PREFETCH);
for(i = 0; i < bufqsize; i++) {
assert(bufq[i] != NULL);
assert(bufq[i]->lmfs_count > 0);
}
/* therefore they are all 'in use' and must be at least this many */
assert(start_in_use >= start_bufqsize);
}
assert(dev != NO_DEV);
assert(fs_block_size > 0);
assert(howmany(fs_block_size, PAGE_SIZE) <= NR_IOREQS);
#endif /* !defined(NDEBUG) */
/* For WRITING, (Shell) sort buffers on lmfs_blocknr.
* For READING, the buffers are already sorted.
*/
if (rw_flag == WRITING)
sort_blocks(bufq, bufqsize);
/* Set up I/O vector and do I/O. The result of bdev I/O is OK if everything
* went fine, otherwise the error code for the first failed transfer.
*/
while (bufqsize > 0) {
unsigned int p, nblocks = 0, niovecs = 0;
int r;
for (iop = iovec; nblocks < bufqsize; nblocks++) {
vir_bytes vdata, blockrem;
bp = bufq[nblocks];
if (bp->lmfs_blocknr != bufq[0]->lmfs_blocknr + nblocks)
break;
blockrem = bp->lmfs_bytes;
iov_per_block = howmany(blockrem, PAGE_SIZE);
if (niovecs > NR_IOREQS - iov_per_block) break;
vdata = (vir_bytes) bp->data;
for(p = 0; p < iov_per_block; p++) {
vir_bytes chunk =
blockrem < PAGE_SIZE ? blockrem : PAGE_SIZE;
iop->iov_addr = vdata;
iop->iov_size = chunk;
vdata += PAGE_SIZE;
blockrem -= chunk;
iop++;
niovecs++;
}
assert(p == iov_per_block);
assert(blockrem == 0);
}
assert(nblocks > 0);
assert(niovecs > 0 && niovecs <= NR_IOREQS);
pos = (off_t)bufq[0]->lmfs_blocknr * fs_block_size;
if (rw_flag == READING)
r = bdev_gather(dev, pos, iovec, niovecs, BDEV_NOFLAGS);
else
r = bdev_scatter(dev, pos, iovec, niovecs, BDEV_NOFLAGS);
/* Harvest the results. The driver may have returned an error, or it
* may have done less than what we asked for.
*/
if (r < 0) {
printf("fs cache: I/O error %d on device %d/%d, "
"block %"PRIu64"\n",
r, major(dev), minor(dev), bufq[0]->lmfs_blocknr);
}
for (i = 0; i < nblocks; i++) {
bp = bufq[i];
if (r < (ssize_t)bp->lmfs_bytes) {
/* Transfer failed. */
if (i == 0) {
bp->lmfs_dev = NO_DEV; /* Invalidate block */
}
break;
}
if (rw_flag == READING) {
lmfs_put_block(bp);
} else {
MARKCLEAN(bp);
}
r -= bp->lmfs_bytes;
}
bufq += i;
bufqsize -= i;
if (rw_flag == READING) {
/* Don't bother reading more than the device is willing to
* give at this time. Don't forget to release those extras.
*/
while (bufqsize > 0) {
bp = *bufq++;
bp->lmfs_dev = NO_DEV; /* invalidate block */
lmfs_put_block(bp);
bufqsize--;
}
}
if (rw_flag == WRITING && i == 0) {
/* We're not making progress, this means we might keep
* looping. Buffers remain dirty if un-written. Buffers are
* lost if invalidate()d or LRU-removed while dirty. This
* is better than keeping unwritable blocks around forever..
*/
break;
}
}
#if !defined(NDEBUG)
if(rw_flag == READING) {
assert(start_in_use >= start_bufqsize);
/* READING callers assume all bufs are released. */
assert(start_in_use - start_bufqsize == bufs_in_use);
}
#endif /* !defined(NDEBUG) */
}
void read_inode_extents(struct inode *i,
const struct iso9660_dir_record *dir_rec,
struct dir_extent *extent, size_t *offset)
{
struct buf *bp;
struct iso9660_dir_record *extent_rec;
struct dir_extent *cur_extent = i->extent;
int done = FALSE;
/*
* No need to search extents if file is empty or has final directory
* record flag set.
*/
if (cur_extent == NULL ||
((dir_rec->file_flags & D_NOT_LAST_EXTENT) == 0))
return;
while (!done) {
bp = fetch_inode(extent, offset);
if (bp == NULL)
return;
bp = read_extent_block(extent,
*offset / v_pri.logical_block_size_l);
extent_rec = (struct iso9660_dir_record*)(b_data(bp) +
*offset % v_pri.logical_block_size_l);
if (check_dir_record(dir_rec,
*offset % v_pri.logical_block_size_l) != OK) {
lmfs_put_block(bp, FULL_DATA_BLOCK);
return;
}
/* Extent entries should share the same name. */
if ((dir_rec->length_file_id == extent_rec->length_file_id) &&
(memcmp(dir_rec->file_id, extent_rec->file_id,
dir_rec->length_file_id) == 0)) {
/* Add the extent at the end of the linked list. */
assert(cur_extent->next == NULL);
cur_extent->next = alloc_extent();
cur_extent->next->location = dir_rec->loc_extent_l +
dir_rec->ext_attr_rec_length;
cur_extent->next->length = dir_rec->data_length_l /
v_pri.logical_block_size_l;
if (dir_rec->data_length_l % v_pri.logical_block_size_l)
cur_extent->next->length++;
i->i_stat.st_size += dir_rec->data_length_l;
i->i_stat.st_blocks += cur_extent->next->length;
cur_extent = cur_extent->next;
*offset += extent_rec->length;
}
else
done = TRUE;
/* Check if not last extent bit is not set. */
if ((dir_rec->file_flags & D_NOT_LAST_EXTENT) == 0)
done = TRUE;
lmfs_put_block(bp, FULL_DATA_BLOCK);
}
}
int parse_susp(struct rrii_dir_record *dir, char *buffer)
{
/* Parse fundamental SUSP entries */
char susp_signature[2];
u8_t susp_length;
u8_t susp_version;
u32_t ca_block_nr;
u32_t ca_offset;
u32_t ca_length;
struct buf *ca_bp;
susp_signature[0] = buffer[0];
susp_signature[1] = buffer[1];
susp_length = *((u8_t*)buffer + 2);
susp_version = *((u8_t*)buffer + 3);
if ((susp_signature[0] == 'C') && (susp_signature[1] == 'E') &&
(susp_length >= 28) && (susp_version >= 1)) {
/*
* Continuation area, perform a recursion.
*
* FIXME: Currently we're parsing only first logical block of a
* continuation area, and infinite recursion is not checked.
*/
ca_block_nr = *((u32_t*)(buffer + 4));
ca_offset = *((u32_t*)(buffer + 12));
ca_length = *((u32_t*)(buffer + 20));
/* Truncate continuation area to fit one logical block. */
if (ca_offset >= v_pri.logical_block_size_l) {
return EINVAL;
}
if (ca_offset + ca_length > v_pri.logical_block_size_l) {
ca_length = v_pri.logical_block_size_l - ca_offset;
}
ca_bp = lmfs_get_block(fs_dev, ca_block_nr, NORMAL);
if (ca_bp == NULL) {
return EINVAL;
}
parse_susp_buffer(dir, b_data(ca_bp) + ca_offset, ca_length);
lmfs_put_block(ca_bp, FULL_DATA_BLOCK);
return OK;
}
else if ((susp_signature[0] == 'P') && (susp_signature[1] == 'D')) {
/* Padding, skip. */
return OK;
}
else if ((susp_signature[0] == 'S') && (susp_signature[1] == 'P')) {
/* Ignored, skip. */
return OK;
}
else if ((susp_signature[0] == 'S') && (susp_signature[1] == 'T')) {
/* Terminator entry, stop processing. */
return(ECANCELED);
}
else if ((susp_signature[0] == 'E') && (susp_signature[1] == 'R')) {
/* Ignored, skip. */
return OK;
}
else if ((susp_signature[0] == 'E') && (susp_signature[1] == 'S')) {
/* Ignored, skip. */
return OK;
}
/* Not a SUSP fundamental entry. */
return EINVAL;
}
