2 * Copyright 2000, International Business Machines Corporation and others.
5 * This software has been released under the terms of the IBM Public
6 * License. For details, see the LICENSE file in the top-level source
7 * directory or online at http://www.openafs.org/dl/license10.html
10 #include "../afs/param.h" /* Should be always first */
11 #include "../afs/sysincludes.h" /* Standard vendor system headers */
12 #include "../afs/afsincludes.h" /* Afs-based standard headers */
13 #include "../afs/afs_stats.h" /* statistics */
15 /* Linux VM operations
17 * The general model for Linux is to treat vm as a cache that's:
18 * 1) explicitly updated by AFS when AFS writes the data to the cache file.
19 * 2) reads go through the cache. A cache miss is satisfied by the filesystem.
21 * This means flushing VM is not required on this OS.
24 /* Try to discard pages, in order to recycle a vcache entry.
26 * We also make some sanity checks: ref count, open count, held locks.
28 * We also do some non-VM-related chores, such as releasing the cred pointer
29 * (for AIX and Solaris) and releasing the gnode (for AIX).
31 * Locking: afs_xvcache lock is held. If it is dropped and re-acquired,
32 * *slept should be set to warn the caller.
34 * Formerly, afs_xvcache was dropped and re-acquired for Solaris, but now it
35 * is not dropped and re-acquired for any platform. It may be that *slept is
36 * therefore obsolescent.
38 int osi_VM_FlushVCache(struct vcache *avc, int *slept)
40 struct inode *ip = (struct inode*)avc;
42 if (avc->vrefCount != 0)
48 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,15)
49 truncate_inode_pages(&ip->i_data, 0);
51 invalidate_inode_pages(ip);
56 /* Try to invalidate pages, for "fs flush" or "fs flushv"; or
57 * try to free pages, when deleting a file.
59 * Locking: the vcache entry's lock is held. It may be dropped and
62 * Since we drop and re-obtain the lock, we can't guarantee that there won't
63 * be some pages around when we return, newly created by concurrent activity.
65 void osi_VM_TryToSmush(struct vcache *avc, struct AFS_UCRED *acred, int sync)
67 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,15)
68 struct inode *ip = (struct inode*)avc;
70 truncate_inode_pages(&ip->i_data, 0);
72 invalidate_inode_pages((struct inode *)avc);
76 /* Flush and invalidate pages, for fsync() with INVAL flag
78 * Locking: only the global lock is held.
80 void osi_VM_FSyncInval(struct vcache *avc)
85 /* Try to store pages to cache, in order to store a file back to the server.
87 * Locking: the vcache entry's lock is held. It will usually be dropped and
90 void osi_VM_StoreAllSegments(struct vcache *avc)
95 /* Purge VM for a file when its callback is revoked.
97 * Locking: No lock is held, not even the global lock.
99 void osi_VM_FlushPages(struct vcache *avc, struct AFS_UCRED *credp)
101 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,15)
102 struct inode *ip = (struct inode*)avc;
104 truncate_inode_pages(&ip->i_data, 0);
106 invalidate_inode_pages((struct inode*)avc);
110 /* Purge pages beyond end-of-file, when truncating a file.
112 * Locking: no lock is held, not even the global lock.
113 * activeV is raised. This is supposed to block pageins, but at present
114 * it only works on Solaris.
116 void osi_VM_Truncate(struct vcache *avc, int alen, struct AFS_UCRED *acred)
118 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,15)
119 struct inode *ip = (struct inode*)avc;
121 truncate_inode_pages(&ip->i_data, alen);
123 invalidate_inode_pages((struct inode*)avc);