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/*
Unix SMB/CIFS implementation.
POSIX NTVFS backend - read
Copyright (C) Andrew Tridgell 2004
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "vfs_posix.h"
#include "lib/events/events.h"
/*
read from a file
*/
NTSTATUS pvfs_read(struct ntvfs_module_context *ntvfs,
struct ntvfs_request *req, union smb_read *rd)
{
struct pvfs_state *pvfs = talloc_get_type(ntvfs->private_data,
struct pvfs_state);
ssize_t ret;
struct pvfs_file *f;
NTSTATUS status;
uint32_t maxcnt;
uint32_t mask;
if (rd->generic.level != RAW_READ_READX) {
return ntvfs_map_read(ntvfs, req, rd);
}
f = pvfs_find_fd(pvfs, req, rd->readx.in.file.ntvfs);
if (!f) {
return NT_STATUS_INVALID_HANDLE;
}
if (f->handle->fd == -1) {
return NT_STATUS_INVALID_DEVICE_REQUEST;
}
mask = SEC_FILE_READ_DATA;
if (rd->readx.in.read_for_execute) {
mask |= SEC_FILE_EXECUTE;
}
if (!(f->access_mask & mask)) {
return NT_STATUS_ACCESS_DENIED;
}
maxcnt = rd->readx.in.maxcnt;
if (maxcnt > UINT16_MAX && req->ctx->protocol < PROTOCOL_SMB2) {
maxcnt = 0;
}
status = pvfs_check_lock(pvfs, f, req->smbpid,
rd->readx.in.offset,
maxcnt,
READ_LOCK);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
if (f->handle->name->stream_name) {
ret = pvfs_stream_read(pvfs, f->handle,
rd->readx.out.data, maxcnt, rd->readx.in.offset);
} else {
#if HAVE_LINUX_AIO
/* possibly try an aio read */
if ((req->async_states->state & NTVFS_ASYNC_STATE_MAY_ASYNC) &&
(pvfs->flags & PVFS_FLAG_LINUX_AIO)) {
status = pvfs_aio_pread(req, rd, f, maxcnt);
if (NT_STATUS_IS_OK(status)) {
return NT_STATUS_OK;
}
}
#endif
ret = pread(f->handle->fd,
rd->readx.out.data,
maxcnt,
rd->readx.in.offset);
}
if (ret == -1) {
return pvfs_map_errno(pvfs, errno);
}
/* only SMB2 honors mincnt */
if (req->ctx->protocol == PROTOCOL_SMB2) {
if (rd->readx.in.mincnt > ret ||
(ret == 0 && maxcnt > 0)) {
return NT_STATUS_END_OF_FILE;
}
}
f->handle->position = f->handle->seek_offset = rd->readx.in.offset + ret;
rd->readx.out.nread = ret;
rd->readx.out.remaining = 0xFFFF;
rd->readx.out.compaction_mode = 0;
return NT_STATUS_OK;
}
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