Author: kib
Date: Thu May 6 19:22:50 2010
New Revision: 207729
URL: http://svn.freebsd.org/changeset/base/207729
Log:
Add MAKEDEV_NOWAIT flag to make_dev_credf(9), to create a device node
in a no-sleep context. If resource allocation cannot be done without
sleep, make_dev_credf() fails and returns NULL.
Reviewed by: jh
MFC after: 2 weeks
Modified:
head/sys/fs/devfs/devfs_devs.c
head/sys/fs/devfs/devfs_int.h
head/sys/kern/kern_conf.c
head/sys/sys/conf.h
Modified: head/sys/fs/devfs/devfs_devs.c
==============================================================================
--- head/sys/fs/devfs/devfs_devs.c Thu May 6 18:58:32 2010
(r207728)
+++ head/sys/fs/devfs/devfs_devs.c Thu May 6 19:22:50 2010
(r207729)
@@ -115,17 +115,21 @@ SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev
0, sizeof(struct cdev_priv), "sizeof(struct cdev_priv)");
struct cdev *
-devfs_alloc(void)
+devfs_alloc(int flags)
{
struct cdev_priv *cdp;
struct cdev *cdev;
struct timespec ts;
- cdp = malloc(sizeof *cdp, M_CDEVP, M_USE_RESERVE | M_ZERO | M_WAITOK);
+ cdp = malloc(sizeof *cdp, M_CDEVP, M_USE_RESERVE | M_ZERO |
+ ((flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK));
+ if (cdp == NULL)
+ return (NULL);
cdp->cdp_dirents = &cdp->cdp_dirent0;
cdp->cdp_dirent0 = NULL;
cdp->cdp_maxdirent = 0;
+ cdp->cdp_inode = 0;
cdev = &cdp->cdp_c;
@@ -133,6 +137,7 @@ devfs_alloc(void)
LIST_INIT(&cdev->si_children);
vfs_timestamp(&ts);
cdev->si_atime = cdev->si_mtime = cdev->si_ctime = ts;
+ cdev->si_cred = NULL;
return (cdev);
}
Modified: head/sys/fs/devfs/devfs_int.h
==============================================================================
--- head/sys/fs/devfs/devfs_int.h Thu May 6 18:58:32 2010
(r207728)
+++ head/sys/fs/devfs/devfs_int.h Thu May 6 19:22:50 2010
(r207729)
@@ -70,7 +70,7 @@ struct cdev_priv {
#define cdev2priv(c) member2struct(cdev_priv, cdp_c, c)
-struct cdev *devfs_alloc(void);
+struct cdev *devfs_alloc(int);
void devfs_free(struct cdev *);
void devfs_create(struct cdev *dev);
void devfs_destroy(struct cdev *dev);
Modified: head/sys/kern/kern_conf.c
==============================================================================
--- head/sys/kern/kern_conf.c Thu May 6 18:58:32 2010 (r207728)
+++ head/sys/kern/kern_conf.c Thu May 6 19:22:50 2010 (r207729)
@@ -505,7 +505,7 @@ giant_mmap_single(struct cdev *dev, vm_o
}
static void
-notify(struct cdev *dev, const char *ev)
+notify(struct cdev *dev, const char *ev, int flags)
{
static const char prefix[] = "cdev=";
char *data;
@@ -514,7 +514,8 @@ notify(struct cdev *dev, const char *ev)
if (cold)
return;
namelen = strlen(dev->si_name);
- data = malloc(namelen + sizeof(prefix), M_TEMP, M_NOWAIT);
+ data = malloc(namelen + sizeof(prefix), M_TEMP,
+ (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
if (data == NULL)
return;
memcpy(data, prefix, sizeof(prefix) - 1);
@@ -524,17 +525,17 @@ notify(struct cdev *dev, const char *ev)
}
static void
-notify_create(struct cdev *dev)
+notify_create(struct cdev *dev, int flags)
{
- notify(dev, "CREATE");
+ notify(dev, "CREATE", flags);
}
static void
notify_destroy(struct cdev *dev)
{
- notify(dev, "DESTROY");
+ notify(dev, "DESTROY", MAKEDEV_WAITOK);
}
static struct cdev *
@@ -572,24 +573,27 @@ fini_cdevsw(struct cdevsw *devsw)
devsw->d_flags &= ~D_INIT;
}
-static void
-prep_cdevsw(struct cdevsw *devsw)
+static int
+prep_cdevsw(struct cdevsw *devsw, int flags)
{
struct cdevsw *dsw2;
mtx_assert(&devmtx, MA_OWNED);
if (devsw->d_flags & D_INIT)
- return;
+ return (1);
if (devsw->d_flags & D_NEEDGIANT) {
dev_unlock();
- dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK);
+ dsw2 = malloc(sizeof *dsw2, M_DEVT,
+ (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
dev_lock();
+ if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
+ return (0);
} else
dsw2 = NULL;
if (devsw->d_flags & D_INIT) {
if (dsw2 != NULL)
cdevsw_free_devlocked(dsw2);
- return;
+ return (1);
}
if (devsw->d_version != D_VERSION_03) {
@@ -647,6 +651,7 @@ prep_cdevsw(struct cdevsw *devsw)
if (dsw2 != NULL)
cdevsw_free_devlocked(dsw2);
+ return (1);
}
static struct cdev *
@@ -657,9 +662,15 @@ make_dev_credv(int flags, struct cdevsw
struct cdev *dev;
int i;
- dev = devfs_alloc();
+ dev = devfs_alloc(flags);
+ if (dev == NULL)
+ return (NULL);
dev_lock();
- prep_cdevsw(devsw);
+ if (!prep_cdevsw(devsw, flags)) {
+ dev_unlock();
+ devfs_free(dev);
+ return (NULL);
+ }
dev = newdev(devsw, unit, dev);
if (flags & MAKEDEV_REF)
dev_refl(dev);
@@ -686,8 +697,6 @@ make_dev_credv(int flags, struct cdevsw
dev->si_flags |= SI_NAMED;
if (cr != NULL)
dev->si_cred = crhold(cr);
- else
- dev->si_cred = NULL;
dev->si_uid = uid;
dev->si_gid = gid;
dev->si_mode = mode;
@@ -696,7 +705,7 @@ make_dev_credv(int flags, struct cdevsw
clean_unrhdrl(devfs_inos);
dev_unlock_and_free();
- notify_create(dev);
+ notify_create(dev, flags);
return (dev);
}
@@ -771,7 +780,7 @@ make_dev_alias(struct cdev *pdev, const
int i;
KASSERT(pdev != NULL, ("NULL pdev"));
- dev = devfs_alloc();
+ dev = devfs_alloc(MAKEDEV_WAITOK);
dev_lock();
dev->si_flags |= SI_ALIAS;
dev->si_flags |= SI_NAMED;
@@ -788,7 +797,7 @@ make_dev_alias(struct cdev *pdev, const
clean_unrhdrl(devfs_inos);
dev_unlock();
- notify_create(dev);
+ notify_create(dev, MAKEDEV_WAITOK);
return (dev);
}
@@ -973,9 +982,9 @@ clone_create(struct clonedevs **cdp, str
* the end of the list.
*/
unit = *up;
- ndev = devfs_alloc();
+ ndev = devfs_alloc(MAKEDEV_WAITOK);
dev_lock();
- prep_cdevsw(csw);
+ prep_cdevsw(csw, MAKEDEV_WAITOK);
low = extra;
de = dl = NULL;
cd = *cdp;
Modified: head/sys/sys/conf.h
==============================================================================
--- head/sys/sys/conf.h Thu May 6 18:58:32 2010 (r207728)
+++ head/sys/sys/conf.h Thu May 6 19:22:50 2010 (r207729)
@@ -262,8 +262,10 @@ struct cdev *make_dev(struct cdevsw *_de
struct cdev *make_dev_cred(struct cdevsw *_devsw, int _unit,
struct ucred *_cr, uid_t _uid, gid_t _gid, int _perms,
const char *_fmt, ...) __printflike(7, 8);
-#define MAKEDEV_REF 0x1
-#define MAKEDEV_WHTOUT 0x2
+#define MAKEDEV_REF 0x1
+#define MAKEDEV_WHTOUT 0x2
+#define MAKEDEV_NOWAIT 0x4
+#define MAKEDEV_WAITOK 0x8
struct cdev *make_dev_credf(int _flags,
struct cdevsw *_devsw, int _unit,
struct ucred *_cr, uid_t _uid, gid_t _gid, int _mode,
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