From c23fbb6bcb3eb9cdf39a103edadf57bde8ce309c Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 8 May 2007 00:26:18 -0700 Subject: VFS: delay the dentry name generation on sockets and pipes 1) Introduces a new method in 'struct dentry_operations'. This method called d_dname() might be called from d_path() to build a pathname for special filesystems. It is called without locks. Future patches (if we succeed in having one common dentry for all pipes/sockets) may need to change prototype of this method, but we now use : char *d_dname(struct dentry *dentry, char *buffer, int buflen); 2) Adds a dynamic_dname() helper function that eases d_dname() implementations 3) Defines d_dname method for sockets : No more sprintf() at socket creation. This is delayed up to the moment someone does an access to /proc/pid/fd/... 4) Defines d_dname method for pipes : No more sprintf() at pipe creation. This is delayed up to the moment someone does an access to /proc/pid/fd/... A benchmark consisting of 1.000.000 calls to pipe()/close()/close() gives a *nice* speedup on my Pentium(M) 1.6 Ghz : 3.090 s instead of 3.450 s Signed-off-by: Eric Dumazet Acked-by: Christoph Hellwig Acked-by: Linus Torvalds Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- net/socket.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) (limited to 'net') diff --git a/net/socket.c b/net/socket.c index 759825b7ca2..98a8f67abbf 100644 --- a/net/socket.c +++ b/net/socket.c @@ -313,8 +313,19 @@ static int sockfs_delete_dentry(struct dentry *dentry) dentry->d_flags |= DCACHE_UNHASHED; return 0; } + +/* + * sockfs_dname() is called from d_path(). + */ +static char *sockfs_dname(struct dentry *dentry, char *buffer, int buflen) +{ + return dynamic_dname(dentry, buffer, buflen, "socket:[%lu]", + dentry->d_inode->i_ino); +} + static struct dentry_operations sockfs_dentry_operations = { .d_delete = sockfs_delete_dentry, + .d_dname = sockfs_dname, }; /* @@ -354,14 +365,9 @@ static int sock_alloc_fd(struct file **filep) static int sock_attach_fd(struct socket *sock, struct file *file) { - struct qstr this; - char name[32]; - - this.len = sprintf(name, "[%lu]", SOCK_INODE(sock)->i_ino); - this.name = name; - this.hash = 0; + struct qstr name = { .name = "" }; - file->f_path.dentry = d_alloc(sock_mnt->mnt_sb->s_root, &this); + file->f_path.dentry = d_alloc(sock_mnt->mnt_sb->s_root, &name); if (unlikely(!file->f_path.dentry)) return -ENOMEM; -- cgit v1.2.3-18-g5258