Page MenuHomeFreeBSD
Files F144672230

D52045.1776109230.diff
No OneTemporary
Actions

Size
3 KB
Referenced Files
None
Subscribers
None

D52045.1776109230.diff
View Options

diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -2519,10 +2519,13 @@
{
struct filedesc *newfdp;
struct filedescent *nfde, *ofde;
+ struct file *fp;
int i, lastfile;
+ bool fork_pass;
MPASS(fdp != NULL);
+ fork_pass = false;
newfdp = fdinit();
FILEDESC_SLOCK(fdp);
for (;;) {
@@ -2533,10 +2536,35 @@
fdgrowtable(newfdp, lastfile + 1);
FILEDESC_SLOCK(fdp);
}
- /* copy all passable descriptors (i.e. not kqueue) */
+
+ /*
+ * Copy all passable descriptors (i.e. not kqueue), and
+ * prepare to handle copyable but not passable descriptors
+ * (kqueues).
+ *
+ * The pass to handle copying is performed after all passable
+ * files are installed into the new file descriptor's table,
+ * since kqueues need all referenced file descriptors already
+ * valid, including other kqueues. For the same reason the
+ * copying is done in two passes by itself, first installing
+ * not fully initialized ('empty') copyable files into the new
+ * fd table, and then giving the subsystems a second chance to
+ * really fill the copied file backing structure with the
+ * content.
+ */
newfdp->fd_freefile = fdp->fd_freefile;
FILEDESC_FOREACH_FDE(fdp, i, ofde) {
- if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 ||
+ const struct fileops *ops;
+
+ ops = ofde->fde_file->f_ops;
+ fp = NULL;
+ if ((ops->fo_flags & DFLAG_FORK) != 0 &&
+ (ofde->fde_flags & UF_FOCLOSE) == 0) {
+ if (ops->fo_fork(newfdp, ofde->fde_file, &fp, p1,
+ curthread) != 0)
+ continue;
+ fork_pass = true;
+ } else if ((ops->fo_flags & DFLAG_PASSABLE) == 0 ||
(ofde->fde_flags & UF_FOCLOSE) != 0 ||
!fhold(ofde->fde_file)) {
if (newfdp->fd_freefile == fdp->fd_freefile)
@@ -2545,11 +2573,30 @@
}
nfde = &newfdp->fd_ofiles[i];
*nfde = *ofde;
+ if (fp != NULL)
+ nfde->fde_file = fp;
filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true);
fdused_init(newfdp, i);
}
MPASS(newfdp->fd_freefile != -1);
FILEDESC_SUNLOCK(fdp);
+
+ /*
+ * Now handle copying kqueues, since all fds, including
+ * kqueues, are in place.
+ */
+ if (__predict_false(fork_pass)) {
+ FILEDESC_FOREACH_FDE(newfdp, i, nfde) {
+ const struct fileops *ops;
+
+ ops = nfde->fde_file->f_ops;
+ if ((ops->fo_flags & DFLAG_FORK) == 0 ||
+ nfde->fde_file == NULL)
+ continue;
+ ops->fo_fork(newfdp, NULL, &nfde->fde_file, p1,
+ curthread);
+ }
+ }
return (newfdp);
}
diff --git a/sys/sys/file.h b/sys/sys/file.h
--- a/sys/sys/file.h
+++ b/sys/sys/file.h
@@ -139,6 +139,8 @@
off_t *offset, off_t *length, int flags,
struct ucred *active_cred, struct thread *td);
typedef int fo_cmp_t(struct file *fp, struct file *fp1, struct thread *td);
+typedef int fo_fork_t(struct filedesc *fdp, struct file *fp, struct file **fp1,
+ struct proc *p1, struct thread *td);
typedef int fo_spare_t(struct file *fp);
typedef int fo_flags_t;
@@ -163,12 +165,14 @@
fo_fallocate_t *fo_fallocate;
fo_fspacectl_t *fo_fspacectl;
fo_cmp_t *fo_cmp;
+ fo_fork_t *fo_fork;
fo_spare_t *fo_spares[8]; /* Spare slots */
fo_flags_t fo_flags; /* DFLAG_* below */
};
#define DFLAG_PASSABLE 0x01 /* may be passed via unix sockets. */
#define DFLAG_SEEKABLE 0x02 /* seekable / nonsequential */
+#define DFLAG_FORK 0x04 /* copy on fork */
#endif /* _KERNEL */
#if defined(_KERNEL) || defined(_WANT_FILE)

File Metadata

Mime Type
text/plain
Expires
Mon, Apr 13, 7:40 PM (1 h, 53 m)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
28339718
Default Alt Text
D52045.1776109230.diff (3 KB)

Event Timeline