/*===========================================================================*
* fs_utime *
*===========================================================================*/
int fs_utime()
{
register struct inode *rip;
register int r;
/* Temporarily open the file. */
if( (rip = get_inode(fs_dev, (ino_t) fs_m_in.REQ_INODE_NR)) == NULL)
return(EINVAL);
/* Only the owner of a file or the super_user can change its time. */
r = OK;
if(read_only(rip) != OK) r = EROFS; /* not even su can touch if R/O */
if(r == OK) {
rip->i_atime = fs_m_in.REQ_ACTIME;
rip->i_mtime = fs_m_in.REQ_MODTIME;
rip->i_update = CTIME; /* discard any stale ATIME and MTIME flags */
IN_MARKDIRTY(rip);
}
put_inode(rip);
return(r);
}
/*===========================================================================*
* fs_link *
*===========================================================================*/
int fs_link()
{
/* Perform the link(name1, name2) system call. */
struct inode *ip, *rip;
register int r;
char string[MFS_NAME_MAX];
struct inode *new_ip;
phys_bytes len;
len = min( (unsigned) fs_m_in.REQ_PATH_LEN, sizeof(string));
/* Copy the link name's last component */
r = sys_safecopyfrom(VFS_PROC_NR, (cp_grant_id_t) fs_m_in.REQ_GRANT,
(vir_bytes) 0, (vir_bytes) string, (size_t) len);
if (r != OK) return r;
NUL(string, len, sizeof(string));
/* Temporarily open the file. */
if( (rip = get_inode(fs_dev, (ino_t) fs_m_in.REQ_INODE_NR)) == NULL)
return(EINVAL);
/* Check to see if the file has maximum number of links already. */
r = OK;
if(rip->i_nlinks >= LINK_MAX)
r = EMLINK;
/* Only super_user may link to directories. */
if(r == OK)
if( (rip->i_mode & I_TYPE) == I_DIRECTORY && caller_uid != SU_UID)
r = EPERM;
/* If error with 'name', return the inode. */
if (r != OK) {
put_inode(rip);
return(r);
}
/* Temporarily open the last dir */
if( (ip = get_inode(fs_dev, (ino_t) fs_m_in.REQ_DIR_INO)) == NULL) {
put_inode(rip);
return(EINVAL);
}
if (ip->i_nlinks == NO_LINK) { /* Dir does not actually exist */
put_inode(rip);
put_inode(ip);
return(ENOENT);
}
/* If 'name2' exists in full (even if no space) set 'r' to error. */
if((new_ip = advance(ip, string, IGN_PERM)) == NULL) {
r = err_code;
if(r == ENOENT)
r = OK;
} else {
put_inode(new_ip);
r = EEXIST;
}
/* Try to link. */
if(r == OK)
r = search_dir(ip, string, &rip->i_num, ENTER, IGN_PERM);
/* If success, register the linking. */
if(r == OK) {
rip->i_nlinks++;
rip->i_update |= CTIME;
IN_MARKDIRTY(rip);
}
/* Done. Release both inodes. */
put_inode(rip);
put_inode(ip);
return(r);
}
/*===========================================================================*
* fs_readwrite *
*===========================================================================*/
PUBLIC 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, (ino_t) fs_m_in.REQ_INODE_NR)) == 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_zone[0]);
f_size = MAX_FILE_POS;
} else {
block_size = rip->i_sp->s_block_size;
f_size = rip->i_size;
}
/* Get the values from the request message */
rw_flag = (fs_m_in.m_type == REQ_READ ? READING : WRITING);
gid = (cp_grant_id_t) fs_m_in.REQ_GRANT;
position = (off_t) fs_m_in.REQ_SEEK_POS_LO;
nrbytes = (size_t) fs_m_in.REQ_NBYTES;
rdwt_err = OK; /* set to EIO if disk error occurs */
/* If this is file i/o, check we can write */
if (rw_flag == WRITING && !block_spec) {
if(rip->i_sp->s_rd_only)
return EROFS;
/* Check in advance to see if file will grow too big. */
if (position > (off_t) (rip->i_sp->s_max_size - nrbytes))
return(EFBIG);
/* Clear the zone containing present EOF if hole about
* to be created. This is necessary because all unwritten
* blocks prior to the EOF must read as zeros.
*/
if(position > f_size) clear_zone(rip, f_size, 0);
}
/* If this is block i/o, check we can write */
if(block_spec && rw_flag == WRITING &&
(dev_t) rip->i_zone[0] == superblock.s_dev && superblock.s_rd_only)
return EROFS;
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 > (unsigned int) bytes_left) chunk = bytes_left;
}
/* Read or write 'chunk' bytes. */
r = rw_chunk(rip, cvul64((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.RES_SEEK_POS_LO = 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;
}
}
rip->i_seek = NO_SEEK;
if (rdwt_err != OK) r = rdwt_err; /* check for disk error */
if (rdwt_err == END_OF_FILE) r = OK;
/* even on a ROFS, writing to a device node on it is fine,
* just don't update the inode stats for it. And dito for reading.
*/
if (r == OK && !rip->i_sp->s_rd_only) {
if (rw_flag == READING) rip->i_update |= ATIME;
if (rw_flag == WRITING) rip->i_update |= CTIME | MTIME;
IN_MARKDIRTY(rip); /* inode is thus now dirty */
}
fs_m_out.RES_NBYTES = cum_io;
return(r);
}
/*===========================================================================*
* fs_readwrite *
*===========================================================================*/
ssize_t fs_readwrite(ino_t ino_nr, struct fsdriver_data *data, size_t nrbytes,
off_t position, int call)
{
int r;
int regular;
off_t f_size, bytes_left;
size_t off, cum_io, block_size, chunk;
mode_t mode_word;
int completed;
struct inode *rip;
r = OK;
/* Find the inode referred */
if ((rip = find_inode(fs_dev, ino_nr)) == NULL)
return(EINVAL);
mode_word = rip->i_mode & I_TYPE;
regular = (mode_word == I_REGULAR);
/* Determine blocksize */
block_size = rip->i_sp->s_block_size;
f_size = rip->i_size;
lmfs_reset_rdwt_err();
/* If this is file i/o, check we can write */
if (call == FSC_WRITE) {
if(rip->i_sp->s_rd_only)
return EROFS;
/* Check in advance to see if file will grow too big. */
if (position > (off_t) (rip->i_sp->s_max_size - nrbytes))
return(EFBIG);
/* Clear the zone containing present EOF if hole about
* to be created. This is necessary because all unwritten
* blocks prior to the EOF must read as zeros.
*/
if(position > f_size) clear_zone(rip, f_size, 0);
}
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 = block_size - off;
if (chunk > nrbytes)
chunk = nrbytes;
if (call == FSC_READ) {
bytes_left = f_size - position;
if (position >= f_size) break; /* we are beyond EOF */
if (chunk > (unsigned int) bytes_left) chunk = bytes_left;
}
/* Read or write 'chunk' bytes. */
r = rw_chunk(rip, ((u64_t)((unsigned long)position)), off, chunk,
nrbytes, call, data, cum_io, block_size, &completed);
if (r != OK) break; /* EOF reached */
if (lmfs_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 */
}
/* On write, update file size and access time. */
if (call == FSC_WRITE) {
if (regular || mode_word == I_DIRECTORY) {
if (position > f_size) rip->i_size = position;
}
}
rip->i_seek = NO_SEEK;
if (lmfs_rdwt_err() != OK) r = lmfs_rdwt_err(); /* check for disk error */
if (lmfs_rdwt_err() == END_OF_FILE) r = OK;
if (r != OK)
return r;
/* even on a ROFS, writing to a device node on it is fine,
* just don't update the inode stats for it. And dito for reading.
*/
if (!rip->i_sp->s_rd_only) {
if (call == FSC_READ) rip->i_update |= ATIME;
if (call == FSC_WRITE) rip->i_update |= CTIME | MTIME;
IN_MARKDIRTY(rip); /* inode is thus now dirty */
}
return cum_io;
}
