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sortix--sortix/kernel/fs/util.cpp
2018-03-31 00:55:33 +02:00

112 lines
3.1 KiB
C++

/*
* Copyright (c) 2012, 2017 Jonas 'Sortie' Termansen.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* fs/util.cpp
* Utility classes for kernel filesystems.
*/
#include <assert.h>
#include <errno.h>
#include <string.h>
#include <sortix/stat.h>
#include <sortix/seek.h>
#include <sortix/kernel/inode.h>
#include <sortix/kernel/interlock.h>
#include <sortix/kernel/ioctx.h>
#include <sortix/kernel/kernel.h>
#include <sortix/kernel/kthread.h>
#include <sortix/kernel/refcount.h>
#include "util.h"
namespace Sortix {
UtilMemoryBuffer::UtilMemoryBuffer(dev_t dev, ino_t ino, uid_t owner,
gid_t group, mode_t mode, uint8_t* buf,
off_t bufsize, bool write, bool deletebuf)
{
assert(0 <= bufsize);
inode_type = INODE_TYPE_FILE;
this->filelock = KTHREAD_MUTEX_INITIALIZER;
this->stat_uid = owner;
this->stat_gid = group;
this->type = S_IFREG;
this->stat_mode = (mode & S_SETABLE) | this->type;
this->stat_size = bufsize;
this->dev = dev;
this->ino = ino ? ino : (ino_t) this;
this->buf = buf;
this->bufsize = bufsize;
this->write = write;
this->deletebuf = deletebuf;
}
UtilMemoryBuffer::~UtilMemoryBuffer()
{
if ( deletebuf )
delete[] buf;
}
int UtilMemoryBuffer::truncate(ioctx_t* /*ctx*/, off_t length)
{
ScopedLock lock(&filelock);
if ( length != bufsize )
return errno = EPERM, -1;
return 0;
}
off_t UtilMemoryBuffer::lseek(ioctx_t* /*ctx*/, off_t offset, int whence)
{
ScopedLock lock(&filelock);
if ( whence == SEEK_END && offset == 0 )
return bufsize;
return errno = EINVAL, -1;
}
ssize_t UtilMemoryBuffer::pread(ioctx_t* ctx, uint8_t* dest, size_t count,
off_t off)
{
ScopedLock lock(&filelock);
if ( bufsize < off )
return 0;
off_t available = bufsize - off;
if ( (uintmax_t) available < (uintmax_t) count )
count = available;
if ( !ctx->copy_to_dest(dest, buf + off, count) )
return -1;
return count;
}
ssize_t UtilMemoryBuffer::pwrite(ioctx_t* ctx, const uint8_t* src, size_t count,
off_t off)
{
ScopedLock lock(&filelock);
if ( !write )
return errno = EROFS, -1;
if ( bufsize < off )
return errno = EFBIG, -1;
off_t available = bufsize - off;
if ( available == 0 && count )
return errno = EFBIG, -1;
if ( (uintmax_t) available < (uintmax_t) count )
count = available;
if ( !ctx->copy_from_src(buf + off, src, count) )
return -1;
return count;
}
} // namespace Sortix