From 412d582ec1dd59aab2353f8cb7e74f2c79cd20b9 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 18 Aug 2005 11:24:11 -0700 Subject: [PATCH] NFS: use atomic bitops to manipulate flags in nfsi->flags Introduce atomic bitops to manipulate the bits in the nfs_inode structure's "flags" field. Using bitops means we can use a generic wait_on_bit call instead of an ad hoc locking scheme in fs/nfs/inode.c, so we can remove the "nfs_i_wait" field from nfs_inode at the same time. The other new flags field will continue to use bitmask and logic AND and OR. This permits several flags to be set at the same time efficiently. The following patch adds a spin lock to protect these flags, and this spin lock will later cover other fields in the nfs_inode structure, amortizing the cost of using this type of serialization. Test plan: Millions of fsx ops on SMP clients. Signed-off-by: Chuck Lever Cc: Trond Myklebust Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nfs/dir.c | 4 ++-- fs/nfs/inode.c | 69 ++++++++++++++++++++++++++++++++++++---------------------- 2 files changed, 45 insertions(+), 28 deletions(-) (limited to 'fs') diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 5732e13cd0da..27cf5577f239 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -182,7 +182,7 @@ int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page) /* We requested READDIRPLUS, but the server doesn't grok it */ if (error == -ENOTSUPP && desc->plus) { NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS; - NFS_FLAGS(inode) &= ~NFS_INO_ADVISE_RDPLUS; + clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode)); desc->plus = 0; goto again; } @@ -545,7 +545,7 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir) break; } if (res == -ETOOSMALL && desc->plus) { - NFS_FLAGS(inode) &= ~NFS_INO_ADVISE_RDPLUS; + clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode)); nfs_zap_caches(inode); desc->plus = 0; desc->entry->eof = 0; diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 622184553516..ee27578277f3 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -739,7 +739,7 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr) inode->i_fop = &nfs_dir_operations; if (nfs_server_capable(inode, NFS_CAP_READDIRPLUS) && fattr->size <= NFS_LIMIT_READDIRPLUS) - NFS_FLAGS(inode) |= NFS_INO_ADVISE_RDPLUS; + set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode)); } else if (S_ISLNK(inode->i_mode)) inode->i_op = &nfs_symlink_inode_operations; else @@ -849,26 +849,43 @@ void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr) } } +static int nfs_wait_schedule(void *word) +{ + if (signal_pending(current)) + return -ERESTARTSYS; + schedule(); + return 0; +} + /* * Wait for the inode to get unlocked. - * (Used for NFS_INO_LOCKED and NFS_INO_REVALIDATING). */ -static int -nfs_wait_on_inode(struct inode *inode, int flag) +static int nfs_wait_on_inode(struct inode *inode) { struct rpc_clnt *clnt = NFS_CLIENT(inode); struct nfs_inode *nfsi = NFS_I(inode); - + sigset_t oldmask; int error; - if (!(NFS_FLAGS(inode) & flag)) - return 0; + atomic_inc(&inode->i_count); - error = nfs_wait_event(clnt, nfsi->nfs_i_wait, - !(NFS_FLAGS(inode) & flag)); + rpc_clnt_sigmask(clnt, &oldmask); + error = wait_on_bit_lock(&nfsi->flags, NFS_INO_REVALIDATING, + nfs_wait_schedule, TASK_INTERRUPTIBLE); + rpc_clnt_sigunmask(clnt, &oldmask); iput(inode); + return error; } +static void nfs_wake_up_inode(struct inode *inode) +{ + struct nfs_inode *nfsi = NFS_I(inode); + + clear_bit(NFS_INO_REVALIDATING, &nfsi->flags); + smp_mb__after_clear_bit(); + wake_up_bit(&nfsi->flags, NFS_INO_REVALIDATING); +} + int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { struct inode *inode = dentry->d_inode; @@ -1029,18 +1046,19 @@ __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode) if (NFS_STALE(inode)) goto out_nowait; - while (NFS_REVALIDATING(inode)) { - status = nfs_wait_on_inode(inode, NFS_INO_REVALIDATING); - if (status < 0) - goto out_nowait; - if (NFS_ATTRTIMEO(inode) == 0) - continue; - if (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ATIME)) - continue; - status = NFS_STALE(inode) ? -ESTALE : 0; - goto out_nowait; + status = nfs_wait_on_inode(inode); + if (status < 0) + goto out; + if (NFS_STALE(inode)) { + status = -ESTALE; + /* Do we trust the cached ESTALE? */ + if (NFS_ATTRTIMEO(inode) != 0) { + if (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ATIME)) { + /* no */ + } else + goto out; + } } - NFS_FLAGS(inode) |= NFS_INO_REVALIDATING; /* Protect against RPC races by saving the change attribute */ verifier = nfs_save_change_attribute(inode); @@ -1052,7 +1070,7 @@ __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode) if (status == -ESTALE) { nfs_zap_caches(inode); if (!S_ISDIR(inode->i_mode)) - NFS_FLAGS(inode) |= NFS_INO_STALE; + set_bit(NFS_INO_STALE, &NFS_FLAGS(inode)); } goto out; } @@ -1083,9 +1101,9 @@ __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode) inode->i_sb->s_id, (long long)NFS_FILEID(inode)); -out: - NFS_FLAGS(inode) &= ~NFS_INO_REVALIDATING; - wake_up(&nfsi->nfs_i_wait); + out: + nfs_wake_up_inode(inode); + out_nowait: unlock_kernel(); return status; @@ -1404,7 +1422,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr, unsign */ nfs_invalidate_inode(inode); out_err: - NFS_FLAGS(inode) |= NFS_INO_STALE; + set_bit(NFS_INO_STALE, &NFS_FLAGS(inode)); return -ESTALE; } @@ -1996,7 +2014,6 @@ static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) nfsi->ndirty = 0; nfsi->ncommit = 0; nfsi->npages = 0; - init_waitqueue_head(&nfsi->nfs_i_wait); nfs4_init_once(nfsi); } } -- cgit v1.2.3-58-ga151