From b23fb0a60379a95e10c671f646b259ea2558421e Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:49:35 +1100 Subject: fs: scale inode alias list Add a new lock, dcache_inode_lock, to protect the inode's i_dentry list from concurrent modification. d_alias is also protected by d_lock. Signed-off-by: Nick Piggin --- fs/nfs/getroot.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'fs/nfs/getroot.c') diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c index ac7b814ce162..850f67d5f0ac 100644 --- a/fs/nfs/getroot.c +++ b/fs/nfs/getroot.c @@ -64,7 +64,11 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i * Oops, since the test for IS_ROOT() will fail. */ spin_lock(&dcache_lock); + spin_lock(&dcache_inode_lock); + spin_lock(&sb->s_root->d_lock); list_del_init(&sb->s_root->d_alias); + spin_unlock(&sb->s_root->d_lock); + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); } return 0; -- cgit v1.2.3 From b5c84bf6f6fa3a7dfdcb556023a62953574b60ee Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:49:38 +1100 Subject: fs: dcache remove dcache_lock dcache_lock no longer protects anything. remove it. Signed-off-by: Nick Piggin --- fs/nfs/getroot.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'fs/nfs/getroot.c') diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c index 850f67d5f0ac..b3e36c3430de 100644 --- a/fs/nfs/getroot.c +++ b/fs/nfs/getroot.c @@ -63,13 +63,11 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i * This again causes shrink_dcache_for_umount_subtree() to * Oops, since the test for IS_ROOT() will fail. */ - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); spin_lock(&sb->s_root->d_lock); list_del_init(&sb->s_root->d_alias); spin_unlock(&sb->s_root->d_lock); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); } return 0; } -- cgit v1.2.3 From fb045adb99d9b7c562dc7fef834857f78249daa1 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:49:55 +1100 Subject: fs: dcache reduce branches in lookup path Reduce some branches and memory accesses in dcache lookup by adding dentry flags to indicate common d_ops are set, rather than having to check them. This saves a pointer memory access (dentry->d_op) in common path lookup situations, and saves another pointer load and branch in cases where we have d_op but not the particular operation. Patched with: git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i Signed-off-by: Nick Piggin --- fs/nfs/getroot.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/nfs/getroot.c') diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c index b3e36c3430de..c3a5a1126833 100644 --- a/fs/nfs/getroot.c +++ b/fs/nfs/getroot.c @@ -121,7 +121,7 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh) security_d_instantiate(ret, inode); if (ret->d_op == NULL) - ret->d_op = server->nfs_client->rpc_ops->dentry_ops; + d_set_d_op(ret, server->nfs_client->rpc_ops->dentry_ops); out: nfs_free_fattr(fsinfo.fattr); return ret; @@ -228,7 +228,7 @@ struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh) security_d_instantiate(ret, inode); if (ret->d_op == NULL) - ret->d_op = server->nfs_client->rpc_ops->dentry_ops; + d_set_d_op(ret, server->nfs_client->rpc_ops->dentry_ops); out: nfs_free_fattr(fattr); -- cgit v1.2.3 From 873feea09ebc980cbd3631b767356ce1eee65ec1 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:50:06 +1100 Subject: fs: dcache per-inode inode alias locking dcache_inode_lock can be replaced with per-inode locking. Use existing inode->i_lock for this. This is slightly non-trivial because we sometimes need to find the inode from the dentry, which requires d_inode to be stabilised (either with refcount or d_lock). Signed-off-by: Nick Piggin --- fs/nfs/getroot.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/nfs/getroot.c') diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c index c3a5a1126833..5596c6a2881e 100644 --- a/fs/nfs/getroot.c +++ b/fs/nfs/getroot.c @@ -63,11 +63,11 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i * This again causes shrink_dcache_for_umount_subtree() to * Oops, since the test for IS_ROOT() will fail. */ - spin_lock(&dcache_inode_lock); + spin_lock(&sb->s_root->d_inode->i_lock); spin_lock(&sb->s_root->d_lock); list_del_init(&sb->s_root->d_alias); spin_unlock(&sb->s_root->d_lock); - spin_unlock(&dcache_inode_lock); + spin_unlock(&sb->s_root->d_inode->i_lock); } return 0; } -- cgit v1.2.3