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* Copyright 2000, International Business Machines Corporation and others.
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* This software has been released under the terms of the IBM Public
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* License. For details, see the LICENSE file in the top-level source
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* directory or online at http://www.openafs.org/dl/license10.html
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#include <afsconfig.h>
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#include "afs/param.h"
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#include "afs/sysincludes.h" /* Standard vendor system headers */
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#include "afsincludes.h" /* Afs-based standard headers */
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#include "afs/afs_stats.h" /* statistics */
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#include "osi_compat.h"
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/* Linux VM operations
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* The general model for Linux is to treat vm as a cache that's:
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* 1) explicitly updated by AFS when AFS writes the data to the cache file.
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* 2) reads go through the cache. A cache miss is satisfied by the filesystem.
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* This means flushing VM is not required on this OS.
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/* Try to discard pages, in order to recycle a vcache entry.
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* We also make some sanity checks: ref count, open count, held locks.
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* We also do some non-VM-related chores, such as releasing the cred pointer
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* (for AIX and Solaris) and releasing the gnode (for AIX).
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* Locking: afs_xvcache lock is held. If it is dropped and re-acquired,
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* *slept should be set to warn the caller.
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* Formerly, afs_xvcache was dropped and re-acquired for Solaris, but now it
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* is not dropped and re-acquired for any platform. It may be that *slept is
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* therefore obsolescent.
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osi_VM_FlushVCache(struct vcache *avc, int *slept)
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struct inode *ip = AFSTOV(avc);
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if (VREFCOUNT(avc) > 1)
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return vmtruncate(ip, 0);
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/* Try to invalidate pages, for "fs flush" or "fs flushv"; or
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* try to free pages, when deleting a file.
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* Locking: the vcache entry's lock is held. It may be dropped and
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* Since we drop and re-obtain the lock, we can't guarantee that there won't
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* be some pages around when we return, newly created by concurrent activity.
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osi_VM_TryToSmush(struct vcache *avc, afs_ucred_t *acred, int sync)
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struct inode *ip = AFSTOV(avc);
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invalidate_remote_inode(ip);
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/* Flush and invalidate pages, for fsync() with INVAL flag
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* Locking: only the global lock is held.
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osi_VM_FSyncInval(struct vcache *avc)
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/* Try to store pages to cache, in order to store a file back to the server.
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* Locking: the vcache entry's lock is held. It will usually be dropped and
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osi_VM_StoreAllSegments(struct vcache *avc)
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struct inode *ip = AFSTOV(avc);
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if (avc->f.states & CPageWrite)
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return; /* someone already writing */
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/* filemap_fdatasync() only exported in 2.4.5 and above */
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ReleaseWriteLock(&avc->lock);
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filemap_fdatawrite(ip->i_mapping);
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filemap_fdatawait(ip->i_mapping);
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ObtainWriteLock(&avc->lock, 121);
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/* Purge VM for a file when its callback is revoked.
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* Locking: No lock is held, not even the global lock.
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/* Note that for speed some of our Linux vnodeops do not initialise credp
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* before calling osi_FlushPages(). If credp is ever required on Linux,
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* then these callers should be updated.
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osi_VM_FlushPages(struct vcache *avc, afs_ucred_t *credp)
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struct inode *ip = AFSTOV(avc);
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afs_linux_lock_inode(ip);
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truncate_inode_pages(&ip->i_data, 0);
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afs_linux_unlock_inode(ip);
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/* Purge pages beyond end-of-file, when truncating a file.
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* Locking: no lock is held, not even the global lock.
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* activeV is raised. This is supposed to block pageins, but at present
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* it only works on Solaris.
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osi_VM_Truncate(struct vcache *avc, int alen, afs_ucred_t *acred)
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vmtruncate(AFSTOV(avc), alen);
added
removed
.pc/3.8-compat/src/afs/LINUX/osi_vm.c
