From: Trond Myklebust Date: Tue, 15 Jul 2008 21:58:13 +0000 (-0400) Subject: NFS: Add options for finer control of the lookup cache X-Git-Tag: v2.6.28-rc1~266^2^2~50 X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=4eec952e42314b53e48fef1f54dd89cbf9789734 NFS: Add options for finer control of the lookup cache Add the flag NFS_MOUNT_LOOKUP_CACHE_NONEG to turn off the caching of negative dentries. In reality what we do is to force nfs_lookup_revalidate() to always discard negative dentries. Add the flag NFS_MOUNT_LOOKUP_CACHE_NONE for enforcing stricter revalidation of dentries. It forces the revalidate code to always do a lookup instead of just checking the cached mtime of the parent directory. Signed-off-by: Trond Myklebust --- diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 74f92b7..49d5654 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -667,6 +667,8 @@ static int nfs_check_verifier(struct inode *dir, struct dentry *dentry) { if (IS_ROOT(dentry)) return 1; + if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) + return 0; if (!nfs_verify_change_attribute(dir, dentry->d_time)) return 0; /* Revalidate nfsi->cache_change_attribute before we declare a match */ @@ -750,6 +752,8 @@ int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, /* Don't revalidate a negative dentry if we're creating a new file */ if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0) return 0; + if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) + return 1; return !nfs_check_verifier(dir, dentry); } diff --git a/include/linux/nfs_mount.h b/include/linux/nfs_mount.h index df7c6b7..6549a06 100644 --- a/include/linux/nfs_mount.h +++ b/include/linux/nfs_mount.h @@ -65,4 +65,8 @@ struct nfs_mount_data { #define NFS_MOUNT_UNSHARED 0x8000 /* 5 */ #define NFS_MOUNT_FLAGMASK 0xFFFF +/* The following are for internal use only */ +#define NFS_MOUNT_LOOKUP_CACHE_NONEG 0x10000 +#define NFS_MOUNT_LOOKUP_CACHE_NONE 0x20000 + #endif