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minix/servers/ext2/read.c
Lionel Sambuc 56350a991b Message types for VFS read, write & peek 
All of these requests share the same message type as at least one server
manages those requests in the same handler, just by checking the actual
type of the request, and then acting upon it.

Change-Id: I17337b4c67ae209523574c22ccc108cf5f1e65e9
2014-07-28 17:05:29 +02:00

773 lines
24 KiB
C
Raw Blame History

/* Created (MFS based):
* February 2010 (Evgeniy Ivanov)
*/
#include "fs.h"
#include <stddef.h>
#include <string.h>
#include <stdlib.h>
#include <minix/com.h>
#include <minix/u64.h>
#include "buf.h"
#include "inode.h"
#include "super.h"
#include <minix/vfsif.h>
#include <minix/minlib.h>
#include <sys/param.h>
#include <assert.h>
#include <sys/param.h>
static struct buf *rahead(struct inode *rip, block_t baseblock, u64_t
position, unsigned bytes_ahead);
static int rw_chunk(struct inode *rip, u64_t position, unsigned off,
size_t chunk, unsigned left, int rw_flag, cp_grant_id_t gid, unsigned
buf_off, unsigned int block_size, int *completed);
static off_t rdahedpos; /* position to read ahead */
static struct inode *rdahed_inode; /* pointer to inode to read ahead */
/*===========================================================================*
* fs_readwrite *
*===========================================================================*/
int fs_readwrite(void)
{
int r, rw_flag, block_spec;
int regular;
cp_grant_id_t gid;
off_t position, f_size, bytes_left;
unsigned int off, cum_io, block_size, chunk;
mode_t mode_word;
int completed;
struct inode *rip;
size_t nrbytes;
r = OK;
/* Find the inode referred */
if ((rip = find_inode(fs_dev, fs_m_in.m_vfs_fs_readwrite.inode)) == NULL)
return(EINVAL);
mode_word = rip->i_mode & I_TYPE;
regular = (mode_word == I_REGULAR || mode_word == I_NAMED_PIPE);
block_spec = (mode_word == I_BLOCK_SPECIAL ? 1 : 0);
/* Determine blocksize */
if (block_spec) {
block_size = get_block_size( (dev_t) rip->i_block[0]);
f_size = MAX_FILE_POS;
} else {
block_size = rip->i_sp->s_block_size;
f_size = rip->i_size;
if (f_size < 0) f_size = MAX_FILE_POS;
}
rw_flag = (fs_m_in.m_type == REQ_READ ? READING : WRITING);
switch(fs_m_in.m_type) {
case REQ_READ: rw_flag = READING; break;
case REQ_WRITE: rw_flag = WRITING; break;
case REQ_PEEK: rw_flag = PEEKING; break;
default: panic("odd request");
}
gid = fs_m_in.m_vfs_fs_readwrite.grant;
position = fs_m_in.m_vfs_fs_readwrite.seek_pos;
nrbytes = fs_m_in.m_vfs_fs_readwrite.nbytes;
rdwt_err = OK; /* set to EIO if disk error occurs */
if (rw_flag == WRITING && !block_spec) {
/* Check in advance to see if file will grow too big. */
if (position > (off_t) (rip->i_sp->s_max_size - nrbytes))
return(EFBIG);
}
cum_io = 0;
/* Split the transfer into chunks that don't span two blocks. */
while (nrbytes != 0) {
off = (unsigned int) (position % block_size);/* offset in blk*/
chunk = MIN(nrbytes, block_size - off);
if (rw_flag == READING) {
bytes_left = f_size - position;
if (position >= f_size) break; /* we are beyond EOF */
if (chunk > bytes_left) chunk = (int) bytes_left;
}
/* Read or write 'chunk' bytes. */
r = rw_chunk(rip, ((u64_t)((unsigned long)position)), off, chunk,
nrbytes, rw_flag, gid, cum_io, block_size, &completed);
if (r != OK) break; /* EOF reached */
if (rdwt_err < 0) break;
/* Update counters and pointers. */
nrbytes -= chunk; /* bytes yet to be read */
cum_io += chunk; /* bytes read so far */
position += (off_t) chunk; /* position within the file */
}
fs_m_out.m_fs_vfs_readwrite.seek_pos = position; /* It might change later
and the VFS has to know
this value */
/* On write, update file size and access time. */
if (rw_flag == WRITING) {
if (regular || mode_word == I_DIRECTORY) {
if (position > f_size) rip->i_size = position;
}
}
/* Check to see if read-ahead is called for, and if so, set it up. */
if(rw_flag == READING && rip->i_seek == NO_SEEK &&
(unsigned int) position % block_size == 0 &&
(regular || mode_word == I_DIRECTORY)) {
rdahed_inode = rip;
rdahedpos = position;
}
rip->i_seek = NO_SEEK;
if (rdwt_err != OK) r = rdwt_err; /* check for disk error */
if (rdwt_err == END_OF_FILE) r = OK;
if (r == OK) {
if (rw_flag == READING) rip->i_update |= ATIME;
if (rw_flag == WRITING) rip->i_update |= CTIME | MTIME;
rip->i_dirt = IN_DIRTY; /* inode is thus now dirty */
}
fs_m_out.m_fs_vfs_readwrite.nbytes = cum_io;
return(r);
}
/*===========================================================================*
* fs_breadwrite *
*===========================================================================*/
int fs_breadwrite(void)
{
int r, rw_flag, completed;
cp_grant_id_t gid;
u64_t position;
unsigned int off, cum_io, chunk, block_size;
size_t nrbytes;
/* Pseudo inode for rw_chunk */
struct inode rip;
r = OK;
/* Get the values from the request message */
rw_flag = (fs_m_in.m_type == REQ_BREAD ? READING : WRITING);
gid = fs_m_in.m_vfs_fs_breadwrite.grant;
position = fs_m_in.m_vfs_fs_breadwrite.seek_pos;
nrbytes = fs_m_in.m_vfs_fs_breadwrite.nbytes;
block_size = get_block_size(fs_m_in.m_vfs_fs_breadwrite.device);
rip.i_block[0] = (block_t) fs_m_in.m_vfs_fs_breadwrite.device;
rip.i_mode = I_BLOCK_SPECIAL;
rip.i_size = 0;
rdwt_err = OK; /* set to EIO if disk error occurs */
cum_io = 0;
/* Split the transfer into chunks that don't span two blocks. */
while (nrbytes > 0) {
off = (unsigned int)(position % block_size); /* offset in blk*/
chunk = min(nrbytes, block_size - off);
/* Read or write 'chunk' bytes. */
r = rw_chunk(&rip, position, off, chunk, nrbytes, rw_flag, gid,
cum_io, block_size, &completed);
if (r != OK) break; /* EOF reached */
if (rdwt_err < 0) break;
/* Update counters and pointers. */
nrbytes -= chunk; /* bytes yet to be read */
cum_io += chunk; /* bytes read so far */
position += chunk; /* position within the file */
}
fs_m_out.m_fs_vfs_breadwrite.seek_pos = position;
if (rdwt_err != OK) r = rdwt_err; /* check for disk error */
if (rdwt_err == END_OF_FILE) r = OK;
fs_m_out.m_fs_vfs_breadwrite.nbytes = cum_io;
return(r);
}
/*===========================================================================*
* rw_chunk *
*===========================================================================*/
static int rw_chunk(rip, position, off, chunk, left, rw_flag, gid,
buf_off, block_size, completed)
register struct inode *rip; /* pointer to inode for file to be rd/wr */
u64_t position; /* position within file to read or write */
unsigned off; /* off within the current block */
unsigned int chunk; /* number of bytes to read or write */
unsigned left; /* max number of bytes wanted after position */
int rw_flag; /* READING, WRITING or PEEKING */
cp_grant_id_t gid; /* grant */
unsigned buf_off; /* offset in grant */
unsigned int block_size; /* block size of FS operating on */
int *completed; /* number of bytes copied */
{
/* Read or write (part of) a block. */
register struct buf *bp = NULL;
register int r = OK;
int n, block_spec;
block_t b;
dev_t dev;
ino_t ino = VMC_NO_INODE;
u64_t ino_off = rounddown(position, block_size);
/* rw_flag:
* READING: read from FS, copy to user
* WRITING: copy from user, write to FS
* PEEKING: try to get all the blocks into the cache, no copying
*/
*completed = 0;
block_spec = (rip->i_mode & I_TYPE) == I_BLOCK_SPECIAL;
if (block_spec) {
b = (unsigned long)(position / block_size);
dev = (dev_t) rip->i_block[0];
} else {
if (ex64hi(position) != 0)
panic("rw_chunk: position too high");
b = read_map(rip, (off_t) ex64lo(position), 0);
dev = rip->i_dev;
ino = rip->i_num;
assert(ino != VMC_NO_INODE);
}
if (!block_spec && b == NO_BLOCK) {
if (rw_flag == READING) {
/* Reading from a nonexistent block. Must read as all zeros.*/
r = sys_safememset(VFS_PROC_NR, gid, (vir_bytes) buf_off,
0, (size_t) chunk);
if(r != OK) {
printf("ext2fs: sys_safememset failed\n");
}
return r;
} else {
/* Writing to or peeking a nonexistent block.
* Create and enter in inode.
*/
if ((bp = new_block(rip, (off_t) ex64lo(position))) == NULL)
return(err_code);
}
} else if (rw_flag == READING || rw_flag == PEEKING) {
/* Read and read ahead if convenient. */
bp = rahead(rip, b, position, left);
} else {
/* Normally an existing block to be partially overwritten is first read
* in. However, a full block need not be read in. If it is already in
* the cache, acquire it, otherwise just acquire a free buffer.
*/
n = (chunk == block_size ? NO_READ : NORMAL);
if (!block_spec && off == 0 && (off_t) ex64lo(position) >= rip->i_size)
n = NO_READ;
if(block_spec) {
assert(ino == VMC_NO_INODE);
bp = get_block(dev, b, n);
} else {
assert(ino != VMC_NO_INODE);
assert(!(ino_off % block_size));
bp = lmfs_get_block_ino(dev, b, n, ino, ino_off);
}
}
/* In all cases, bp now points to a valid buffer. */
if (bp == NULL)
panic("bp not valid in rw_chunk, this can't happen");
if (rw_flag == WRITING && chunk != block_size && !block_spec &&
(off_t) ex64lo(position) >= rip->i_size && off == 0) {
zero_block(bp);
}
if (rw_flag == READING) {
/* Copy a chunk from the block buffer to user space. */
r = sys_safecopyto(VFS_PROC_NR, gid, (vir_bytes) buf_off,
(vir_bytes) (b_data(bp)+off), (size_t) chunk);
} else if(rw_flag == WRITING) {
/* Copy a chunk from user space to the block buffer. */
r = sys_safecopyfrom(VFS_PROC_NR, gid, (vir_bytes) buf_off,
(vir_bytes) (b_data(bp)+off), (size_t) chunk);
lmfs_markdirty(bp);
}
n = (off + chunk == block_size ? FULL_DATA_BLOCK : PARTIAL_DATA_BLOCK);
put_block(bp, n);
return(r);
}
/*===========================================================================*
* read_map *
*===========================================================================*/
block_t read_map(rip, position, opportunistic)
register struct inode *rip; /* ptr to inode to map from */
off_t position; /* position in file whose blk wanted */
int opportunistic;
{
/* Given an inode and a position within the corresponding file, locate the
* block number in which that position is to be found and return it.
*/
struct buf *bp;
int mindex;
block_t b;
unsigned long excess, block_pos;
static char first_time = TRUE;
static long addr_in_block;
static long addr_in_block2;
static long doub_ind_s;
static long triple_ind_s;
static long out_range_s;
int iomode = NORMAL;
if(opportunistic) iomode = PREFETCH;
if (first_time) {
addr_in_block = rip->i_sp->s_block_size / BLOCK_ADDRESS_BYTES;
addr_in_block2 = addr_in_block * addr_in_block;
doub_ind_s = EXT2_NDIR_BLOCKS + addr_in_block;
triple_ind_s = doub_ind_s + addr_in_block2;
out_range_s = triple_ind_s + addr_in_block2 * addr_in_block;
first_time = FALSE;
}
block_pos = position / rip->i_sp->s_block_size; /* relative blk # in file */
/* Is 'position' to be found in the inode itself? */
if (block_pos < EXT2_NDIR_BLOCKS)
return(rip->i_block[block_pos]);
/* It is not in the inode, so it must be single, double or triple indirect */
if (block_pos < doub_ind_s) {
b = rip->i_block[EXT2_NDIR_BLOCKS]; /* address of single indirect block */
mindex = block_pos - EXT2_NDIR_BLOCKS;
} else if (block_pos >= out_range_s) { /* TODO: do we need it? */
return(NO_BLOCK);
} else {
/* double or triple indirect block. At first if it's triple,
* find double indirect block.
*/
excess = block_pos - doub_ind_s;
b = rip->i_block[EXT2_DIND_BLOCK];
if (block_pos >= triple_ind_s) {
b = rip->i_block[EXT2_TIND_BLOCK];
if (b == NO_BLOCK) return(NO_BLOCK);
bp = get_block(rip->i_dev, b, NORMAL); /* get triple ind block */
ASSERT(lmfs_dev(bp) != NO_DEV);
ASSERT(lmfs_dev(bp) == rip->i_dev);
excess = block_pos - triple_ind_s;
mindex = excess / addr_in_block2;
b = rd_indir(bp, mindex); /* num of double ind block */
put_block(bp, INDIRECT_BLOCK); /* release triple ind block */
excess = excess % addr_in_block2;
}
if (b == NO_BLOCK) return(NO_BLOCK);
bp = get_block(rip->i_dev, b, iomode); /* get double indirect block */
if(opportunistic && lmfs_dev(bp) == NO_DEV) {
put_block(bp, INDIRECT_BLOCK);
return NO_BLOCK;
}
ASSERT(lmfs_dev(bp) != NO_DEV);
ASSERT(lmfs_dev(bp) == rip->i_dev);
mindex = excess / addr_in_block;
b = rd_indir(bp, mindex); /* num of single ind block */
put_block(bp, INDIRECT_BLOCK); /* release double ind block */
mindex = excess % addr_in_block; /* index into single ind blk */
}
if (b == NO_BLOCK) return(NO_BLOCK);
bp = get_block(rip->i_dev, b, iomode); /* get single indirect block */
if(opportunistic && lmfs_dev(bp) == NO_DEV) {
put_block(bp, INDIRECT_BLOCK);
return NO_BLOCK;
}
ASSERT(lmfs_dev(bp) != NO_DEV);
ASSERT(lmfs_dev(bp) == rip->i_dev);
b = rd_indir(bp, mindex);
put_block(bp, INDIRECT_BLOCK); /* release single ind block */
return(b);
}
struct buf *get_block_map(register struct inode *rip, u64_t position)
{
block_t b = read_map(rip, position, 0); /* get block number */
int block_size = get_block_size(rip->i_dev);
if(b == NO_BLOCK)
return NULL;
position = rounddown(position, block_size);
assert(rip->i_num != VMC_NO_INODE);
return lmfs_get_block_ino(rip->i_dev, b, NORMAL, rip->i_num, position);
}
/*===========================================================================*
* rd_indir *
*===========================================================================*/
block_t rd_indir(bp, mindex)
struct buf *bp; /* pointer to indirect block */
int mindex; /* index into *bp */
{
if (bp == NULL)
panic("rd_indir() on NULL");
/* TODO: use conv call */
return conv4(le_CPU, b_ind(bp)[mindex]);
}
/*===========================================================================*
* read_ahead *
*===========================================================================*/
void read_ahead()
{
/* Read a block into the cache before it is needed. */
unsigned int block_size;
register struct inode *rip;
struct buf *bp;
block_t b;
if(!rdahed_inode)
return;
rip = rdahed_inode; /* pointer to inode to read ahead from */
block_size = get_block_size(rip->i_dev);
rdahed_inode = NULL; /* turn off read ahead */
if ( (b = read_map(rip, rdahedpos, 1)) == NO_BLOCK) return; /* at EOF */
assert(rdahedpos >= 0); /* So we can safely cast it to unsigned below */
bp = rahead(rip, b, ((u64_t)((unsigned long)rdahedpos)), block_size);
put_block(bp, PARTIAL_DATA_BLOCK);
}
/*===========================================================================*
* rahead *
*===========================================================================*/
static struct buf *rahead(rip, baseblock, position, bytes_ahead)
register struct inode *rip; /* pointer to inode for file to be read */
block_t baseblock; /* block at current position */
u64_t position; /* position within file */
unsigned bytes_ahead; /* bytes beyond position for immediate use */
{
/* Fetch a block from the cache or the device. If a physical read is
* required, prefetch as many more blocks as convenient into the cache.
* This usually covers bytes_ahead and is at least BLOCKS_MINIMUM.
* The device driver may decide it knows better and stop reading at a
* cylinder boundary (or after an error). Rw_scattered() puts an optional
* flag on all reads to allow this.
*/
/* Minimum number of blocks to prefetch. */
# define BLOCKS_MINIMUM (nr_bufs < 50 ? 18 : 32)
int nr_bufs = lmfs_nr_bufs();
int block_spec, read_q_size;
unsigned int blocks_ahead, fragment, block_size;
block_t block, blocks_left;
off_t ind1_pos;
dev_t dev;
struct buf *bp = NULL;
static unsigned int readqsize = 0;
static struct buf **read_q = NULL;
u64_t position_running;
if(readqsize != nr_bufs) {
if(readqsize > 0) {
assert(read_q != NULL);
free(read_q);
read_q = NULL;
readqsize = 0;
}
assert(readqsize == 0);
assert(read_q == NULL);
if(!(read_q = malloc(sizeof(read_q[0])*nr_bufs)))
panic("couldn't allocate read_q");
readqsize = nr_bufs;
}
block_spec = (rip->i_mode & I_TYPE) == I_BLOCK_SPECIAL;
if (block_spec)
dev = (dev_t) rip->i_block[0];
else
dev = rip->i_dev;
assert(dev != NO_DEV);
block_size = get_block_size(dev);
block = baseblock;
fragment = position % block_size;
position -= fragment;
position_running = position;
bytes_ahead += fragment;
blocks_ahead = (bytes_ahead + block_size - 1) / block_size;
if(block_spec)
bp = get_block(dev, block, PREFETCH);
else
bp = lmfs_get_block_ino(dev, block, PREFETCH, rip->i_num, position);
assert(bp != NULL);
if (lmfs_dev(bp) != NO_DEV) return(bp);
/* The best guess for the number of blocks to prefetch: A lot.
* It is impossible to tell what the device looks like, so we don't even
* try to guess the geometry, but leave it to the driver.
*
* The floppy driver can read a full track with no rotational delay, and it
* avoids reading partial tracks if it can, so handing it enough buffers to
* read two tracks is perfect. (Two, because some diskette types have
* an odd number of sectors per track, so a block may span tracks.)
*
* The disk drivers don't try to be smart. With todays disks it is
* impossible to tell what the real geometry looks like, so it is best to
* read as much as you can. With luck the caching on the drive allows
* for a little time to start the next read.
*
* The current solution below is a bit of a hack, it just reads blocks from
* the current file position hoping that more of the file can be found. A
* better solution must look at the already available
* indirect blocks (but don't call read_map!).
*/
if (block_spec && rip->i_size == 0) {
blocks_left = (block_t) NR_IOREQS;
} else {
blocks_left = (block_t) (rip->i_size-ex64lo(position)+(block_size-1)) /
block_size;
/* Go for the first indirect block if we are in its neighborhood. */
if (!block_spec) {
ind1_pos = (EXT2_NDIR_BLOCKS) * block_size;
if ((off_t) ex64lo(position) <= ind1_pos && rip->i_size > ind1_pos) {
blocks_ahead++;
blocks_left++;
}
}
}
/* No more than the maximum request. */
if (blocks_ahead > NR_IOREQS) blocks_ahead = NR_IOREQS;
/* Read at least the minimum number of blocks, but not after a seek. */
if (blocks_ahead < BLOCKS_MINIMUM && rip->i_seek == NO_SEEK)
blocks_ahead = BLOCKS_MINIMUM;
/* Can't go past end of file. */
if (blocks_ahead > blocks_left) blocks_ahead = blocks_left;
read_q_size = 0;
/* Acquire block buffers. */
for (;;) {
block_t thisblock;
read_q[read_q_size++] = bp;
if (--blocks_ahead == 0) break;
/* Don't trash the cache, leave 4 free. */
if (lmfs_bufs_in_use() >= nr_bufs - 4) break;
block++;
position_running += block_size;
if(!block_spec &&
(thisblock = read_map(rip, (off_t) ex64lo(position_running), 1)) != NO_BLOCK) {
bp = lmfs_get_block_ino(dev, thisblock, PREFETCH, rip->i_num, position_running);
} else {
bp = get_block(dev, block, PREFETCH);
}
if (lmfs_dev(bp) != NO_DEV) {
/* Oops, block already in the cache, get out. */
put_block(bp, FULL_DATA_BLOCK);
break;
}
}
lmfs_rw_scattered(dev, read_q, read_q_size, READING);
if(block_spec)
return get_block(dev, baseblock, NORMAL);
return(lmfs_get_block_ino(dev, baseblock, NORMAL, rip->i_num, position));
}
/*===========================================================================*
* fs_getdents *
*===========================================================================*/
int fs_getdents(void)
{
#define GETDENTS_BUFSIZE (sizeof(struct dirent) + EXT2_NAME_MAX + 1)
#define GETDENTS_ENTRIES 8
static char getdents_buf[GETDENTS_BUFSIZE * GETDENTS_ENTRIES];
struct inode *rip;
int r, done;
unsigned int block_size, len, reclen;
ino_t ino;
cp_grant_id_t gid;
size_t size, tmpbuf_off, userbuf_off;
off_t pos, off, block_pos, new_pos, ent_pos;
struct buf *bp;
struct ext2_disk_dir_desc *d_desc;
struct dirent *dep;
ino = fs_m_in.m_vfs_fs_getdents.inode;
gid = fs_m_in.m_vfs_fs_getdents.grant;
size = fs_m_in.m_vfs_fs_getdents.mem_size;
pos = fs_m_in.m_vfs_fs_getdents.seek_pos;
/* Check whether the position is properly aligned */
if ((unsigned int) pos % DIR_ENTRY_ALIGN)
return(ENOENT);
if ((rip = get_inode(fs_dev, ino)) == NULL)
return(EINVAL);
block_size = rip->i_sp->s_block_size;
off = (pos % block_size); /* Offset in block */
block_pos = pos - off;
done = FALSE; /* Stop processing directory blocks when done is set */
memset(getdents_buf, '\0', sizeof(getdents_buf)); /* Avoid leaking any data */
tmpbuf_off = 0; /* Offset in getdents_buf */
userbuf_off = 0; /* Offset in the user's buffer */
/* The default position for the next request is EOF. If the user's buffer
* fills up before EOF, new_pos will be modified. */
new_pos = rip->i_size;
for (; block_pos < rip->i_size; block_pos += block_size) {
off_t temp_pos = block_pos;
/* Since directories don't have holes, 'bp' cannot be NULL. */
bp = get_block_map(rip, block_pos); /* get a dir block */
assert(bp != NULL);
assert(bp != NULL);
/* Search a directory block. */
d_desc = (struct ext2_disk_dir_desc*) &b_data(bp);
/* we need to seek to entry at off bytes.
* when NEXT_DISC_DIR_POS == block_size it's last dentry.
*/
for (; temp_pos + conv2(le_CPU, d_desc->d_rec_len) <= pos
&& NEXT_DISC_DIR_POS(d_desc, &b_data(bp)) < block_size;
d_desc = NEXT_DISC_DIR_DESC(d_desc)) {
temp_pos += conv2(le_CPU, d_desc->d_rec_len);
}
for (; CUR_DISC_DIR_POS(d_desc, &b_data(bp)) < block_size;
d_desc = NEXT_DISC_DIR_DESC(d_desc)) {
if (d_desc->d_ino == 0)
continue; /* Entry is not in use */
#if 0
/* read.c:682: error: comparison is always false due to
* limited range of data type
*/
if (d_desc->d_name_len > NAME_MAX ||
d_desc->d_name_len > EXT2_NAME_MAX) {
len = min(NAME_MAX, EXT2_NAME_MAX);
} else
#endif
{
len = d_desc->d_name_len;
}
assert(len <= NAME_MAX);
assert(len <= EXT2_NAME_MAX);
/* Compute record length, incl alignment. */
reclen = _DIRENT_RECLEN(dep, len);
/* Need the position of this entry in the directory */
ent_pos = block_pos + ((char *)d_desc - b_data(bp));
if (userbuf_off + tmpbuf_off + reclen >= size) {
/* The user has no space for one more record */
done = TRUE;
/* Record the position of this entry, it is the
* starting point of the next request (unless the
* position is modified with lseek).
*/
new_pos = ent_pos;
break;
}
if (tmpbuf_off + reclen >= GETDENTS_BUFSIZE*GETDENTS_ENTRIES) {
r = sys_safecopyto(VFS_PROC_NR, gid,
(vir_bytes) userbuf_off,
(vir_bytes) getdents_buf,
(size_t) tmpbuf_off);
if (r != OK) {
put_inode(rip);
return(r);
}
userbuf_off += tmpbuf_off;
tmpbuf_off = 0;
}
dep = (struct dirent *) &getdents_buf[tmpbuf_off];
dep->d_fileno = (ino_t) conv4(le_CPU, d_desc->d_ino);
dep->d_reclen = (unsigned short) reclen;
dep->d_namlen = len;
memcpy(dep->d_name, d_desc->d_name, len);
dep->d_name[len] = '\0';
{
struct inode *entrip;
if(!(entrip = get_inode(fs_dev, dep->d_fileno)))
panic("unexpected get_inode failure");
dep->d_type = fs_mode_to_type(entrip->i_mode);
put_inode(entrip);
}
tmpbuf_off += reclen;
}
put_block(bp, DIRECTORY_BLOCK);
if (done)
break;
}
if (tmpbuf_off != 0) {
r = sys_safecopyto(VFS_PROC_NR, gid, (vir_bytes) userbuf_off,
(vir_bytes) getdents_buf, (size_t) tmpbuf_off);
if (r != OK) {
put_inode(rip);
return(r);
}
userbuf_off += tmpbuf_off;
}
if (done && userbuf_off == 0)
r = EINVAL; /* The user's buffer is too small */
else {
fs_m_out.m_fs_vfs_getdents.nbytes = userbuf_off;
fs_m_out.m_fs_vfs_getdents.seek_pos = new_pos;
rip->i_update |= ATIME;
rip->i_dirt = IN_DIRTY;
r = OK;
}
put_inode(rip); /* release the inode */
return(r);
}
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