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 --- include/linux/nfs_fs.h | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 229a1755842..deef9567788 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -112,8 +112,8 @@ struct nfs_inode { /* * Various flags */ - unsigned int flags; - unsigned long cache_validity; + unsigned long flags; /* atomic bit ops */ + unsigned long cache_validity; /* bit mask */ /* * read_cache_jiffies is when we started read-caching this inode, @@ -175,8 +175,6 @@ struct nfs_inode { /* Open contexts for shared mmap writes */ struct list_head open_files; - wait_queue_head_t nfs_i_wait; - #ifdef CONFIG_NFS_V4 struct nfs4_cached_acl *nfs4_acl; /* NFSv4 state */ @@ -199,11 +197,11 @@ struct nfs_inode { #define NFS_INO_REVAL_PAGECACHE 0x0020 /* must revalidate pagecache */ /* - * Legal values of flags field + * Bit offsets in flags field */ -#define NFS_INO_REVALIDATING 0x0001 /* revalidating attrs */ -#define NFS_INO_ADVISE_RDPLUS 0x0002 /* advise readdirplus */ -#define NFS_INO_STALE 0x0004 /* possible stale inode */ +#define NFS_INO_REVALIDATING (0) /* revalidating attrs */ +#define NFS_INO_ADVISE_RDPLUS (1) /* advise readdirplus */ +#define NFS_INO_STALE (2) /* possible stale inode */ static inline struct nfs_inode *NFS_I(struct inode *inode) { @@ -229,8 +227,7 @@ static inline struct nfs_inode *NFS_I(struct inode *inode) #define NFS_ATTRTIMEO_UPDATE(inode) (NFS_I(inode)->attrtimeo_timestamp) #define NFS_FLAGS(inode) (NFS_I(inode)->flags) -#define NFS_REVALIDATING(inode) (NFS_FLAGS(inode) & NFS_INO_REVALIDATING) -#define NFS_STALE(inode) (NFS_FLAGS(inode) & NFS_INO_STALE) +#define NFS_STALE(inode) (test_bit(NFS_INO_STALE, &NFS_FLAGS(inode))) #define NFS_FILEID(inode) (NFS_I(inode)->fileid) @@ -252,7 +249,7 @@ static inline int nfs_server_capable(struct inode *inode, int cap) static inline int NFS_USE_READDIRPLUS(struct inode *inode) { - return NFS_FLAGS(inode) & NFS_INO_ADVISE_RDPLUS; + return test_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode)); } /** -- cgit v1.2.3