d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add MAKEDEV_NOWAIT flag to make_dev_credf(9), to create a device node

Browse Source 
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
This commit is contained in:
Konstantin Belousov 2010-05-06 19:22:50 +00:00
parent eb00b276ab
commit d2ba618a63
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=207729
4 changed files with 40 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
sys/fs/devfs/devfs_devs.c
View File

@ -115,17 +115,21 @@ SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev_priv, CTLFLAG_RD,
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);
}

2
sys/fs/devfs/devfs_int.h
View File

@ -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);

47
sys/kern/kern_conf.c
View File

@ -505,7 +505,7 @@ giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
}
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 *devsw, int unit,
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 *devsw, int unit,
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 *devsw, int unit,
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 char *fmt, ...)
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 char *fmt, ...)
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, struct cdevsw *csw, int *up,
* 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;

6
sys/sys/conf.h
View File

@ -262,8 +262,10 @@ struct cdev *make_dev(struct cdevsw *_devsw, int _unit, uid_t _uid, gid_t _gid,
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,