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DEFINITIONS
This source file includes following definitions.
- pvfs_read
1 /*
2 Unix SMB/CIFS implementation.
3
4 POSIX NTVFS backend - read
5
6 Copyright (C) Andrew Tridgell 2004
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22 #include "includes.h"
23 #include "vfs_posix.h"
24 #include "lib/events/events.h"
25
26 /*
27 read from a file
28 */
29 NTSTATUS pvfs_read(struct ntvfs_module_context *ntvfs,
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30 struct ntvfs_request *req, union smb_read *rd)
31 {
32 struct pvfs_state *pvfs = talloc_get_type(ntvfs->private_data,
33 struct pvfs_state);
34 ssize_t ret;
35 struct pvfs_file *f;
36 NTSTATUS status;
37 uint32_t maxcnt;
38 uint32_t mask;
39
40 if (rd->generic.level != RAW_READ_READX) {
41 return ntvfs_map_read(ntvfs, req, rd);
42 }
43
44 f = pvfs_find_fd(pvfs, req, rd->readx.in.file.ntvfs);
45 if (!f) {
46 return NT_STATUS_INVALID_HANDLE;
47 }
48
49 if (f->handle->fd == -1) {
50 return NT_STATUS_INVALID_DEVICE_REQUEST;
51 }
52
53 mask = SEC_FILE_READ_DATA;
54 if (rd->readx.in.read_for_execute) {
55 mask |= SEC_FILE_EXECUTE;
56 }
57 if (!(f->access_mask & mask)) {
58 return NT_STATUS_ACCESS_DENIED;
59 }
60
61 maxcnt = rd->readx.in.maxcnt;
62 if (maxcnt > UINT16_MAX && req->ctx->protocol < PROTOCOL_SMB2) {
63 maxcnt = 0;
64 }
65
66 status = pvfs_check_lock(pvfs, f, req->smbpid,
67 rd->readx.in.offset,
68 maxcnt,
69 READ_LOCK);
70 if (!NT_STATUS_IS_OK(status)) {
71 return status;
72 }
73
74 if (f->handle->name->stream_name) {
75 ret = pvfs_stream_read(pvfs, f->handle,
76 rd->readx.out.data, maxcnt, rd->readx.in.offset);
77 } else {
78 #if HAVE_LINUX_AIO
79 /* possibly try an aio read */
80 if ((req->async_states->state & NTVFS_ASYNC_STATE_MAY_ASYNC) &&
81 (pvfs->flags & PVFS_FLAG_LINUX_AIO)) {
82 status = pvfs_aio_pread(req, rd, f, maxcnt);
83 if (NT_STATUS_IS_OK(status)) {
84 return NT_STATUS_OK;
85 }
86 }
87 #endif
88 ret = pread(f->handle->fd,
89 rd->readx.out.data,
90 maxcnt,
91 rd->readx.in.offset);
92 }
93 if (ret == -1) {
94 return pvfs_map_errno(pvfs, errno);
95 }
96
97 /* only SMB2 honors mincnt */
98 if (req->ctx->protocol == PROTOCOL_SMB2) {
99 if (rd->readx.in.mincnt > ret ||
100 (ret == 0 && maxcnt > 0)) {
101 return NT_STATUS_END_OF_FILE;
102 }
103 }
104
105 f->handle->position = f->handle->seek_offset = rd->readx.in.offset + ret;
106
107 rd->readx.out.nread = ret;
108 rd->readx.out.remaining = 0xFFFF;
109 rd->readx.out.compaction_mode = 0;
110
111 return NT_STATUS_OK;
112 }