From ef79c097bbe9724e13937271b3457df560e00370 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 3 Apr 2009 16:42:43 +0100 Subject: NFS: Use local disk inode cache Bind data storage objects in the local cache to NFS inodes. Signed-off-by: David Howells Acked-by: Steve Dickson Acked-by: Trond Myklebust Acked-by: Al Viro Tested-by: Daire Byrne --- fs/nfs/fscache.c | 162 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) (limited to 'fs/nfs/fscache.c') diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c index ab2de2c92b2..e3816eb53fb 100644 --- a/fs/nfs/fscache.c +++ b/fs/nfs/fscache.c @@ -166,3 +166,165 @@ void nfs_fscache_release_super_cookie(struct super_block *sb) nfss->fscache_key = NULL; } } + +/* + * Initialise the per-inode cache cookie pointer for an NFS inode. + */ +void nfs_fscache_init_inode_cookie(struct inode *inode) +{ + NFS_I(inode)->fscache = NULL; + if (S_ISREG(inode->i_mode)) + set_bit(NFS_INO_FSCACHE, &NFS_I(inode)->flags); +} + +/* + * Get the per-inode cache cookie for an NFS inode. + */ +static void nfs_fscache_enable_inode_cookie(struct inode *inode) +{ + struct super_block *sb = inode->i_sb; + struct nfs_inode *nfsi = NFS_I(inode); + + if (nfsi->fscache || !NFS_FSCACHE(inode)) + return; + + if ((NFS_SB(sb)->options & NFS_OPTION_FSCACHE)) { + nfsi->fscache = fscache_acquire_cookie( + NFS_SB(sb)->fscache, + &nfs_fscache_inode_object_def, + nfsi); + + dfprintk(FSCACHE, "NFS: get FH cookie (0x%p/0x%p/0x%p)\n", + sb, nfsi, nfsi->fscache); + } +} + +/* + * Release a per-inode cookie. + */ +void nfs_fscache_release_inode_cookie(struct inode *inode) +{ + struct nfs_inode *nfsi = NFS_I(inode); + + dfprintk(FSCACHE, "NFS: clear cookie (0x%p/0x%p)\n", + nfsi, nfsi->fscache); + + fscache_relinquish_cookie(nfsi->fscache, 0); + nfsi->fscache = NULL; +} + +/* + * Retire a per-inode cookie, destroying the data attached to it. + */ +void nfs_fscache_zap_inode_cookie(struct inode *inode) +{ + struct nfs_inode *nfsi = NFS_I(inode); + + dfprintk(FSCACHE, "NFS: zapping cookie (0x%p/0x%p)\n", + nfsi, nfsi->fscache); + + fscache_relinquish_cookie(nfsi->fscache, 1); + nfsi->fscache = NULL; +} + +/* + * Turn off the cache with regard to a per-inode cookie if opened for writing, + * invalidating all the pages in the page cache relating to the associated + * inode to clear the per-page caching. + */ +static void nfs_fscache_disable_inode_cookie(struct inode *inode) +{ + clear_bit(NFS_INO_FSCACHE, &NFS_I(inode)->flags); + + if (NFS_I(inode)->fscache) { + dfprintk(FSCACHE, + "NFS: nfsi 0x%p turning cache off\n", NFS_I(inode)); + + /* Need to invalidate any mapped pages that were read in before + * turning off the cache. + */ + if (inode->i_mapping && inode->i_mapping->nrpages) + invalidate_inode_pages2(inode->i_mapping); + + nfs_fscache_zap_inode_cookie(inode); + } +} + +/* + * wait_on_bit() sleep function for uninterruptible waiting + */ +static int nfs_fscache_wait_bit(void *flags) +{ + schedule(); + return 0; +} + +/* + * Lock against someone else trying to also acquire or relinquish a cookie + */ +static inline void nfs_fscache_inode_lock(struct inode *inode) +{ + struct nfs_inode *nfsi = NFS_I(inode); + + while (test_and_set_bit(NFS_INO_FSCACHE_LOCK, &nfsi->flags)) + wait_on_bit(&nfsi->flags, NFS_INO_FSCACHE_LOCK, + nfs_fscache_wait_bit, TASK_UNINTERRUPTIBLE); +} + +/* + * Unlock cookie management lock + */ +static inline void nfs_fscache_inode_unlock(struct inode *inode) +{ + struct nfs_inode *nfsi = NFS_I(inode); + + smp_mb__before_clear_bit(); + clear_bit(NFS_INO_FSCACHE_LOCK, &nfsi->flags); + smp_mb__after_clear_bit(); + wake_up_bit(&nfsi->flags, NFS_INO_FSCACHE_LOCK); +} + +/* + * Decide if we should enable or disable local caching for this inode. + * - For now, with NFS, only regular files that are open read-only will be able + * to use the cache. + * - May be invoked multiple times in parallel by parallel nfs_open() functions. + */ +void nfs_fscache_set_inode_cookie(struct inode *inode, struct file *filp) +{ + if (NFS_FSCACHE(inode)) { + nfs_fscache_inode_lock(inode); + if ((filp->f_flags & O_ACCMODE) != O_RDONLY) + nfs_fscache_disable_inode_cookie(inode); + else + nfs_fscache_enable_inode_cookie(inode); + nfs_fscache_inode_unlock(inode); + } +} + +/* + * Replace a per-inode cookie due to revalidation detecting a file having + * changed on the server. + */ +void nfs_fscache_reset_inode_cookie(struct inode *inode) +{ + struct nfs_inode *nfsi = NFS_I(inode); + struct nfs_server *nfss = NFS_SERVER(inode); + struct fscache_cookie *old = nfsi->fscache; + + nfs_fscache_inode_lock(inode); + if (nfsi->fscache) { + /* retire the current fscache cache and get a new one */ + fscache_relinquish_cookie(nfsi->fscache, 1); + + nfsi->fscache = fscache_acquire_cookie( + nfss->nfs_client->fscache, + &nfs_fscache_inode_object_def, + nfsi); + + dfprintk(FSCACHE, + "NFS: revalidation new cookie (0x%p/0x%p/0x%p/0x%p)\n", + nfss, nfsi, old, nfsi->fscache); + } + nfs_fscache_inode_unlock(inode); +} -- cgit v1.2.3