Author: mjg
Date: Fri Oct 31 09:19:46 2014
New Revision: 273894
URL: https://svnweb.freebsd.org/changeset/base/273894
Log:
filedesc: iterate over fd table only once in fdcopy
While here add 'fdused_init' which does not perform unnecessary work.
Drop FILEDESC_LOCK_ASSERT from fdisused and rely on callers to hold
it when appropriate. This function is only used with INVARIANTS.
No functional changes intended.
Modified:
head/sys/kern/kern_descrip.c
Modified: head/sys/kern/kern_descrip.c
==============================================================================
--- head/sys/kern/kern_descrip.c Fri Oct 31 09:15:59 2014
(r273893)
+++ head/sys/kern/kern_descrip.c Fri Oct 31 09:19:46 2014
(r273894)
@@ -238,8 +238,6 @@ static int
fdisused(struct filedesc *fdp, int fd)
{
- FILEDESC_LOCK_ASSERT(fdp);
-
KASSERT(fd >= 0 && fd < fdp->fd_nfiles,
("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles));
@@ -251,14 +249,21 @@ fdisused(struct filedesc *fdp, int fd)
* Mark a file descriptor as used.
*/
static void
-fdused(struct filedesc *fdp, int fd)
+fdused_init(struct filedesc *fdp, int fd)
{
- FILEDESC_XLOCK_ASSERT(fdp);
-
KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd));
fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd);
+}
+
+static void
+fdused(struct filedesc *fdp, int fd)
+{
+
+ FILEDESC_XLOCK_ASSERT(fdp);
+
+ fdused_init(fdp, fd);
if (fd > fdp->fd_lastfile)
fdp->fd_lastfile = fd;
if (fd == fdp->fd_freefile)
@@ -1912,28 +1917,23 @@ fdcopy(struct filedesc *fdp)
newfdp->fd_freefile = -1;
for (i = 0; i <= fdp->fd_lastfile; ++i) {
ofde = &fdp->fd_ofiles[i];
- if (ofde->fde_file != NULL &&
- ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) {
- nfde = &newfdp->fd_ofiles[i];
- *nfde = *ofde;
- filecaps_copy(&ofde->fde_caps, &nfde->fde_caps);
- fhold(nfde->fde_file);
- newfdp->fd_lastfile = i;
- } else {
+ if (ofde->fde_file == NULL ||
+ (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) {
if (newfdp->fd_freefile == -1)
newfdp->fd_freefile = i;
+ continue;
}
- }
- newfdp->fd_cmask = fdp->fd_cmask;
- FILEDESC_SUNLOCK(fdp);
- FILEDESC_XLOCK(newfdp);
- for (i = 0; i <= newfdp->fd_lastfile; ++i) {
- if (newfdp->fd_ofiles[i].fde_file != NULL)
- fdused(newfdp, i);
+ nfde = &newfdp->fd_ofiles[i];
+ *nfde = *ofde;
+ filecaps_copy(&ofde->fde_caps, &nfde->fde_caps);
+ fhold(nfde->fde_file);
+ fdused_init(newfdp, i);
+ newfdp->fd_lastfile = i;
}
if (newfdp->fd_freefile == -1)
newfdp->fd_freefile = i;
- FILEDESC_XUNLOCK(newfdp);
+ newfdp->fd_cmask = fdp->fd_cmask;
+ FILEDESC_SUNLOCK(fdp);
return (newfdp);
}
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