svn commit: r185298 - head/sys/kern

[Joe Marcus Clarke]

Author: marcus (doc,ports committer)
Date: Tue Nov 25 15:36:15 2008
New Revision: 185298
URL: http://svn.freebsd.org/changeset/base/185298

Log:
  Move vn_fullpath1() outside of FILEDESC locking.  This is being done in
  advance of teaching vn_fullpath1() how to query file systems for
  vnode-to-name mappings when cache lookups fail.
  
  Thanks to kib for guidance and patience on this process.
  
  Reviewed by:	kib
  Approved by:	kib

Modified:
  head/sys/kern/vfs_cache.c

Modified: head/sys/kern/vfs_cache.c
==============================================================================
--- head/sys/kern/vfs_cache.c	Tue Nov 25 14:14:58 2008	(r185297)
+++ head/sys/kern/vfs_cache.c	Tue Nov 25 15:36:15 2008	(r185298)
@@ -716,7 +716,8 @@ kern___getcwd(struct thread *td, u_char 
 {
 	char *bp, *tmpbuf;
 	struct filedesc *fdp;
-	int error;
+	struct vnode *cdir, *rdir;
+	int error, vfslocked;
 
 	if (disablecwd)
 		return (ENODEV);
@@ -728,9 +729,18 @@ kern___getcwd(struct thread *td, u_char 
 	tmpbuf = malloc(buflen, M_TEMP, M_WAITOK);
 	fdp = td->td_proc->p_fd;
 	FILEDESC_SLOCK(fdp);
-	error = vn_fullpath1(td, fdp->fd_cdir, fdp->fd_rdir, tmpbuf,
-	    &bp, buflen);
+	cdir = fdp->fd_cdir;
+	VREF(cdir);
+	rdir = fdp->fd_rdir;
+	VREF(rdir);
 	FILEDESC_SUNLOCK(fdp);
+	error = vn_fullpath1(td, cdir, rdir, tmpbuf, &bp, buflen);
+	vfslocked = VFS_LOCK_GIANT(rdir->v_mount);
+	vrele(rdir);
+	VFS_UNLOCK_GIANT(vfslocked);
+	vfslocked = VFS_LOCK_GIANT(cdir->v_mount);
+	vrele(cdir);
+	VFS_UNLOCK_GIANT(vfslocked);
 
 	if (!error) {
 		if (bufseg == UIO_SYSSPACE)
@@ -771,7 +781,8 @@ vn_fullpath(struct thread *td, struct vn
 {
 	char *buf;
 	struct filedesc *fdp;
-	int error;
+	struct vnode *rdir;
+	int error, vfslocked;
 
 	if (disablefullpath)
 		return (ENODEV);
@@ -781,8 +792,13 @@ vn_fullpath(struct thread *td, struct vn
 	buf = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 	fdp = td->td_proc->p_fd;
 	FILEDESC_SLOCK(fdp);
-	error = vn_fullpath1(td, vn, fdp->fd_rdir, buf, retbuf, MAXPATHLEN);
+	rdir = fdp->fd_rdir;
+	VREF(rdir);
 	FILEDESC_SUNLOCK(fdp);
+	error = vn_fullpath1(td, vn, rdir, buf, retbuf, MAXPATHLEN);
+	vfslocked = VFS_LOCK_GIANT(rdir->v_mount);
+	vrele(rdir);
+	VFS_UNLOCK_GIANT(vfslocked);
 
 	if (!error)
 		*freebuf = buf;