1From: Suresh Jayaraman <sjayaraman@suse.de>
2Subject: [RFC][PATCH 06/10] cifs: define inode-level cache object and register them
3Date: Tue, 22 Jun 2010 20:53:33 +0530
4Lines: 318
5Message-ID: <1277220214-3597-1-git-send-email-sjayaraman@suse.de>
6References: <yes>
7Cc: linux-cifs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
8	linux-kernel@vger.kernel.org, David Howells <dhowells@redhat.com>
9To: Steve French <smfrench@gmail.com>
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35
36Define inode-level data storage objects (managed by cifsInodeInfo structs).
37Each inode-level object is created in a super-block level object and is itself
38a data storage object in to which pages from the inode are stored.
39
40The inode object is keyed by UniqueId. The coherency data being used is
41LastWriteTime and the file size.
42
43Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
44---
45 fs/cifs/cache.c    |   80 +++++++++++++++++++++++++++++++++++++++++++++++++++++
46 fs/cifs/cifsfs.c   |    7 ++++
47 fs/cifs/cifsglob.h |    3 +
48 fs/cifs/file.c     |    6 +++
49 fs/cifs/fscache.c  |   68 +++++++++++++++++++++++++++++++++++++++++++++
50 fs/cifs/fscache.h  |   12 +++++++
51 fs/cifs/inode.c    |    4 ++
52 7 files changed, 180 insertions(+)
53
54Index: cifs-2.6/fs/cifs/cache.c
55===================================================================
56--- cifs-2.6.orig/fs/cifs/cache.c
57+++ cifs-2.6/fs/cifs/cache.c
58@@ -138,3 +138,83 @@ const struct fscache_cookie_def cifs_fsc
59 	.get_key = cifs_super_get_key,
60 };
61
62+/*
63+ * Auxiliary data attached to CIFS inode within the cache
64+ */
65+struct cifs_fscache_inode_auxdata {
66+	struct timespec	last_write_time;
67+	loff_t		size;
68+};
69+
70+static uint16_t cifs_fscache_inode_get_key(const void *cookie_netfs_data,
71+					   void *buffer, uint16_t maxbuf)
72+{
73+	const struct cifsInodeInfo *cifsi = cookie_netfs_data;
74+	uint16_t keylen;
75+
76+	/* use the UniqueId as the key */
77+	keylen = sizeof(cifsi->uniqueid);
78+	if (keylen > maxbuf)
79+		keylen = 0;
80+	else
81+		memcpy(buffer, &cifsi->uniqueid, keylen);
82+
83+	return keylen;
84+}
85+
86+static void
87+cifs_fscache_inode_get_attr(const void *cookie_netfs_data, uint64_t *size)
88+{
89+	const struct cifsInodeInfo *cifsi = cookie_netfs_data;
90+
91+	*size = cifsi->vfs_inode.i_size;
92+}
93+
94+static uint16_t
95+cifs_fscache_inode_get_aux(const void *cookie_netfs_data, void *buffer,
96+			   uint16_t maxbuf)
97+{
98+	struct cifs_fscache_inode_auxdata auxdata;
99+	const struct cifsInodeInfo *cifsi = cookie_netfs_data;
100+
101+	memset(&auxdata, 0, sizeof(auxdata));
102+	auxdata.size = cifsi->vfs_inode.i_size;
103+	auxdata.last_write_time = cifsi->vfs_inode.i_ctime;
104+
105+	if (maxbuf > sizeof(auxdata))
106+		maxbuf = sizeof(auxdata);
107+
108+	memcpy(buffer, &auxdata, maxbuf);
109+
110+	return maxbuf;
111+}
112+
113+static enum
114+fscache_checkaux cifs_fscache_inode_check_aux(void *cookie_netfs_data,
115+					      const void *data,
116+					      uint16_t datalen)
117+{
118+	struct cifs_fscache_inode_auxdata auxdata;
119+	struct cifsInodeInfo *cifsi = cookie_netfs_data;
120+
121+	if (datalen != sizeof(auxdata))
122+		return FSCACHE_CHECKAUX_OBSOLETE;
123+
124+	memset(&auxdata, 0, sizeof(auxdata));
125+	auxdata.size = cifsi->vfs_inode.i_size;
126+	auxdata.last_write_time = cifsi->vfs_inode.i_ctime;
127+
128+	if (memcmp(data, &auxdata, datalen) != 0)
129+		return FSCACHE_CHECKAUX_OBSOLETE;
130+
131+	return FSCACHE_CHECKAUX_OKAY;
132+}
133+
134+const struct fscache_cookie_def cifs_fscache_inode_object_def = {
135+	.name		= "CIFS.uniqueid",
136+	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
137+	.get_key	= cifs_fscache_inode_get_key,
138+	.get_attr	= cifs_fscache_inode_get_attr,
139+	.get_aux	= cifs_fscache_inode_get_aux,
140+	.check_aux	= cifs_fscache_inode_check_aux,
141+};
142Index: cifs-2.6/fs/cifs/cifsfs.c
143===================================================================
144--- cifs-2.6.orig/fs/cifs/cifsfs.c
145+++ cifs-2.6/fs/cifs/cifsfs.c
146@@ -330,6 +330,12 @@ cifs_destroy_inode(struct inode *inode)
147 }
148
149 static void
150+cifs_clear_inode(struct inode *inode)
151+{
152+	cifs_fscache_release_inode_cookie(inode);
153+}
154+
155+static void
156 cifs_show_address(struct seq_file *s, struct TCP_Server_Info *server)
157 {
158 	seq_printf(s, ",addr=");
159@@ -490,6 +496,7 @@ static const struct super_operations cif
160 	.alloc_inode = cifs_alloc_inode,
161 	.destroy_inode = cifs_destroy_inode,
162 	.drop_inode	= cifs_drop_inode,
163+	.clear_inode	= cifs_clear_inode,
164 /*	.delete_inode	= cifs_delete_inode,  */  /* Do not need above
165 	function unless later we add lazy close of inodes or unless the
166 	kernel forgets to call us with the same number of releases (closes)
167Index: cifs-2.6/fs/cifs/cifsglob.h
168===================================================================
169--- cifs-2.6.orig/fs/cifs/cifsglob.h
170+++ cifs-2.6/fs/cifs/cifsglob.h
171@@ -407,6 +407,9 @@ struct cifsInodeInfo {
172 	bool invalid_mapping:1;		/* pagecache is invalid */
173 	u64  server_eof;		/* current file size on server */
174 	u64  uniqueid;			/* server inode number */
175+#ifdef CONFIG_CIFS_FSCACHE
176+	struct fscache_cookie *fscache;
177+#endif
178 	struct inode vfs_inode;
179 };
180
181Index: cifs-2.6/fs/cifs/file.c
182===================================================================
183--- cifs-2.6.orig/fs/cifs/file.c
184+++ cifs-2.6/fs/cifs/file.c
185@@ -40,6 +40,7 @@
186 #include "cifs_unicode.h"
187 #include "cifs_debug.h"
188 #include "cifs_fs_sb.h"
189+#include "fscache.h"
190
191 static inline int cifs_convert_flags(unsigned int flags)
192 {
193@@ -282,6 +283,9 @@ int cifs_open(struct inode *inode, struc
194 				CIFSSMBClose(xid, tcon, netfid);
195 				rc = -ENOMEM;
196 			}
197+
198+			cifs_fscache_set_inode_cookie(inode, file);
199+
200 			goto out;
201 		} else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
202 			if (tcon->ses->serverNOS)
203@@ -373,6 +377,8 @@ int cifs_open(struct inode *inode, struc
204 		goto out;
205 	}
206
207+	cifs_fscache_set_inode_cookie(inode, file);
208+
209 	if (oplock & CIFS_CREATE_ACTION) {
210 		/* time to set mode which we can not set earlier due to
211 		   problems creating new read-only files */
212Index: cifs-2.6/fs/cifs/fscache.c
213===================================================================
214--- cifs-2.6.orig/fs/cifs/fscache.c
215+++ cifs-2.6/fs/cifs/fscache.c
216@@ -62,3 +62,71 @@ void cifs_fscache_release_super_cookie(s
217 	tcon->fscache = NULL;
218 }
219
220+static void cifs_fscache_enable_inode_cookie(struct inode *inode)
221+{
222+	struct cifsInodeInfo *cifsi = CIFS_I(inode);
223+	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
224+
225+	if (cifsi->fscache)
226+		return;
227+
228+	cifsi->fscache = fscache_acquire_cookie(cifs_sb->tcon->fscache,
229+				&cifs_fscache_inode_object_def,
230+				cifsi);
231+	cFYI(1, "CIFS: got FH cookie (0x%p/0x%p/0x%p)\n",
232+			cifs_sb->tcon, cifsi, cifsi->fscache);
233+}
234+
235+void cifs_fscache_release_inode_cookie(struct inode *inode)
236+{
237+	struct cifsInodeInfo *cifsi = CIFS_I(inode);
238+
239+	if (cifsi->fscache) {
240+		cFYI(1, "CIFS releasing inode cookie (0x%p/0x%p)\n",
241+				cifsi, cifsi->fscache);
242+		fscache_relinquish_cookie(cifsi->fscache, 0);
243+		cifsi->fscache = NULL;
244+	}
245+}
246+
247+static void cifs_fscache_disable_inode_cookie(struct inode *inode)
248+{
249+	struct cifsInodeInfo *cifsi = CIFS_I(inode);
250+
251+	if (cifsi->fscache) {
252+		cFYI(1, "CIFS disabling inode cookie (0x%p/0x%p)\n",
253+				cifsi, cifsi->fscache);
254+		fscache_relinquish_cookie(cifsi->fscache, 1);
255+		cifsi->fscache = NULL;
256+	}
257+}
258+
259+void cifs_fscache_set_inode_cookie(struct inode *inode, struct file *filp)
260+{
261+	/* BB: parallel opens - need locking? */
262+	if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
263+		cifs_fscache_disable_inode_cookie(inode);
264+	else {
265+		cifs_fscache_enable_inode_cookie(inode);
266+		cFYI(1, "CIFS: fscache inode cookie set\n");
267+	}
268+}
269+
270+void cifs_fscache_reset_inode_cookie(struct inode *inode)
271+{
272+	struct cifsInodeInfo *cifsi = CIFS_I(inode);
273+	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
274+	struct fscache_cookie *old = cifsi->fscache;
275+
276+	if (cifsi->fscache) {
277+		/* retire the current fscache cache and get a new one */
278+		fscache_relinquish_cookie(cifsi->fscache, 1);
279+
280+		cifsi->fscache = fscache_acquire_cookie(cifs_sb->tcon->fscache,
281+					&cifs_fscache_inode_object_def,
282+					cifsi);
283+		cFYI(1, "CIFS: new cookie (0x%p/0x%p) oldcookie 0x%p\n",
284+				cifsi, cifsi->fscache, old);
285+	}
286+}
287+
288Index: cifs-2.6/fs/cifs/fscache.h
289===================================================================
290--- cifs-2.6.orig/fs/cifs/fscache.h
291+++ cifs-2.6/fs/cifs/fscache.h
292@@ -29,6 +29,8 @@
293 extern struct fscache_netfs cifs_fscache_netfs;
294 extern const struct fscache_cookie_def cifs_fscache_server_index_def;
295 extern const struct fscache_cookie_def cifs_fscache_super_index_def;
296+extern const struct fscache_cookie_def cifs_fscache_inode_object_def;
297+
298
299 extern int cifs_fscache_register(void);
300 extern void cifs_fscache_unregister(void);
301@@ -41,6 +43,10 @@ extern void cifs_fscache_release_client_
302 extern void cifs_fscache_get_super_cookie(struct cifsTconInfo *);
303 extern void cifs_fscache_release_super_cookie(struct cifsTconInfo *);
304
305+extern void cifs_fscache_release_inode_cookie(struct inode *);
306+extern void cifs_fscache_set_inode_cookie(struct inode *, struct file *);
307+extern void cifs_fscache_reset_inode_cookie(struct inode *);
308+
309 #else /* CONFIG_CIFS_FSCACHE */
310 static inline int cifs_fscache_register(void) { return 0; }
311 static inline void cifs_fscache_unregister(void) {}
312@@ -53,6 +59,12 @@ static inline void cifs_fscache_get_supe
313 static inline void
314 cifs_fscache_release_super_cookie(struct cifsTconInfo *tcon) {}
315
316+static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {}
317+static inline void cifs_fscache_set_inode_cookie(struct inode *inode,
318+			struct file *filp) {}
319+static inline void cifs_fscache_reset_inode_cookie(struct inode *inode) {}
320+
321+
322 #endif /* CONFIG_CIFS_FSCACHE */
323
324 #endif /* _CIFS_FSCACHE_H */
325Index: cifs-2.6/fs/cifs/inode.c
326===================================================================
327--- cifs-2.6.orig/fs/cifs/inode.c
328+++ cifs-2.6/fs/cifs/inode.c
329@@ -29,6 +29,7 @@
330 #include "cifsproto.h"
331 #include "cifs_debug.h"
332 #include "cifs_fs_sb.h"
333+#include "fscache.h"
334
335
336 static void cifs_set_ops(struct inode *inode, const bool is_dfs_referral)
337@@ -776,6 +777,8 @@ retry_iget5_locked:
338 			inode->i_flags |= S_NOATIME | S_NOCMTIME;
339 		if (inode->i_state & I_NEW) {
340 			inode->i_ino = hash;
341+			/* initialize per-inode cache cookie pointer */
342+			CIFS_I(inode)->fscache = NULL;
343 			unlock_new_inode(inode);
344 		}
345 	}
346@@ -1568,6 +1571,7 @@ cifs_invalidate_mapping(struct inode *in
347 			cifs_i->write_behind_rc = rc;
348 	}
349 	invalidate_remote_inode(inode);
350+	cifs_fscache_reset_inode_cookie(inode);
351 }
352
353 int cifs_revalidate_file(struct file *filp)
354
355
356