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author | kib <kib@FreeBSD.org> | 2008-05-21 09:31:44 +0000 |
---|---|---|
committer | kib <kib@FreeBSD.org> | 2008-05-21 09:31:44 +0000 |
commit | 5971791c189c2ddb0bee3aadd934e064d60bf299 (patch) | |
tree | d53ea3307f3403eee99e9e7722a901bbe968da35 /sys | |
parent | 24431c62bbd3a2bf725a240b11c756552e0fa3ff (diff) | |
download | FreeBSD-src-5971791c189c2ddb0bee3aadd934e064d60bf299.zip FreeBSD-src-5971791c189c2ddb0bee3aadd934e064d60bf299.tar.gz |
Implement the per-open file data for the cdev.
The patch does not change the cdevsw KBI. Management of the data is
provided by the functions
int devfs_set_cdevpriv(void *priv, cdevpriv_dtr_t dtr);
int devfs_get_cdevpriv(void **datap);
void devfs_clear_cdevpriv(void);
All of the functions are supposed to be called from the cdevsw method
contexts.
- devfs_set_cdevpriv assigns the priv as private data for the file
descriptor which is used to initiate currently performed driver
operation. dtr is the function that will be called when either the
last refernce to the file goes away, the device is destroyed or
devfs_clear_cdevpriv is called.
- devfs_get_cdevpriv is the obvious accessor.
- devfs_clear_cdevpriv allows to clear the private data for the still
open file.
Implementation keeps the driver-supplied pointers in the struct
cdev_privdata, that is referenced both from the struct file and struct
cdev, and cannot outlive any of the referee.
Man pages will be provided after the KPI stabilizes.
Reviewed by: jhb
Useful suggestions from: jeff, antoine
Debugging help and tested by: pho
MFC after: 1 month
Diffstat (limited to 'sys')
-rw-r--r-- | sys/fs/devfs/devfs_int.h | 11 | ||||
-rw-r--r-- | sys/fs/devfs/devfs_vnops.c | 110 | ||||
-rw-r--r-- | sys/kern/kern_conf.c | 11 | ||||
-rw-r--r-- | sys/kern/kern_descrip.c | 6 | ||||
-rw-r--r-- | sys/sys/conf.h | 6 | ||||
-rw-r--r-- | sys/sys/file.h | 2 | ||||
-rw-r--r-- | sys/sys/proc.h | 1 |
7 files changed, 144 insertions, 3 deletions
diff --git a/sys/fs/devfs/devfs_int.h b/sys/fs/devfs/devfs_int.h index 3848ab4..df0ad56 100644 --- a/sys/fs/devfs/devfs_int.h +++ b/sys/fs/devfs/devfs_int.h @@ -39,6 +39,13 @@ struct devfs_dirent; +struct cdev_privdata { + struct file *cdpd_fp; + void *cdpd_data; + void (*cdpd_dtr)(void *); + LIST_ENTRY(cdev_privdata) cdpd_list; +}; + struct cdev_priv { struct cdev cdp_c; TAILQ_ENTRY(cdev_priv) cdp_list; @@ -57,17 +64,21 @@ struct cdev_priv { TAILQ_ENTRY(cdev_priv) cdp_dtr_list; void (*cdp_dtr_cb)(void *); void *cdp_dtr_cb_arg; + + LIST_HEAD(, cdev_privdata) cdp_fdpriv; }; struct cdev *devfs_alloc(void); void devfs_free(struct cdev *); void devfs_create(struct cdev *dev); void devfs_destroy(struct cdev *dev); +void devfs_destroy_cdevpriv(struct cdev_privdata *p); extern struct unrhdr *devfs_inos; extern struct mtx devmtx; extern struct mtx devfs_de_interlock; extern struct sx clone_drain_lock; +extern struct mtx cdevpriv_mtx; extern TAILQ_HEAD(cdev_priv_list, cdev_priv) cdevp_list; #endif /* _KERNEL */ diff --git a/sys/fs/devfs/devfs_vnops.c b/sys/fs/devfs/devfs_vnops.c index 21d8ba9..6c3f8fb 100644 --- a/sys/fs/devfs/devfs_vnops.c +++ b/sys/fs/devfs/devfs_vnops.c @@ -73,10 +73,14 @@ static struct fileops devfs_ops_f; #include <security/mac/mac_framework.h> +static MALLOC_DEFINE(M_CDEVPDATA, "DEVFSP", "Metainfo for cdev-fp data"); + struct mtx devfs_de_interlock; MTX_SYSINIT(devfs_de_interlock, &devfs_de_interlock, "devfs interlock", MTX_DEF); struct sx clone_drain_lock; SX_SYSINIT(clone_drain_lock, &clone_drain_lock, "clone events drain lock"); +struct mtx cdevpriv_mtx; +MTX_SYSINIT(cdevpriv_mtx, &cdevpriv_mtx, "cdevpriv lock", MTX_DEF); static int devfs_fp_check(struct file *fp, struct cdev **devp, struct cdevsw **dswp) @@ -92,9 +96,97 @@ devfs_fp_check(struct file *fp, struct cdev **devp, struct cdevsw **dswp) ("devfs: un-referenced struct cdev *(%s)", devtoname(*devp))); if (*dswp == NULL) return (ENXIO); + curthread->td_fpop = fp; return (0); } +int +devfs_get_cdevpriv(void **datap) +{ + struct file *fp; + struct cdev_privdata *p; + int error; + + fp = curthread->td_fpop; + if (fp == NULL) + return (EBADF); + mtx_lock(&cdevpriv_mtx); + p = fp->f_cdevpriv; + mtx_unlock(&cdevpriv_mtx); + if (p != NULL) { + error = 0; + *datap = p->cdpd_data; + } else + error = ENOENT; + return (error); +} + +int +devfs_set_cdevpriv(void *priv, cdevpriv_dtr_t priv_dtr) +{ + struct file *fp; + struct cdev_priv *cdp; + struct cdev_privdata *p; + int error; + + fp = curthread->td_fpop; + if (fp == NULL) + return (ENOENT); + cdp = ((struct cdev *)fp->f_data)->si_priv; + p = malloc(sizeof(struct cdev_privdata), M_CDEVPDATA, M_WAITOK); + p->cdpd_data = priv; + p->cdpd_dtr = priv_dtr; + p->cdpd_fp = fp; + mtx_lock(&cdevpriv_mtx); + if (fp->f_cdevpriv == NULL) { + LIST_INSERT_HEAD(&cdp->cdp_fdpriv, p, cdpd_list); + fp->f_cdevpriv = p; + mtx_unlock(&cdevpriv_mtx); + error = 0; + } else { + mtx_unlock(&cdevpriv_mtx); + free(p, M_CDEVPDATA); + error = EBUSY; + } + return (error); +} + +void +devfs_destroy_cdevpriv(struct cdev_privdata *p) +{ + + mtx_assert(&cdevpriv_mtx, MA_OWNED); + p->cdpd_fp->f_cdevpriv = NULL; + LIST_REMOVE(p, cdpd_list); + mtx_unlock(&cdevpriv_mtx); + (p->cdpd_dtr)(p->cdpd_data); + free(p, M_CDEVPDATA); +} + +void +devfs_fpdrop(struct file *fp) +{ + struct cdev_privdata *p; + + mtx_lock(&cdevpriv_mtx); + if ((p = fp->f_cdevpriv) == NULL) { + mtx_unlock(&cdevpriv_mtx); + return; + } + devfs_destroy_cdevpriv(p); +} + +void +devfs_clear_cdevpriv(void) +{ + struct file *fp; + + fp = curthread->td_fpop; + if (fp == NULL) + return; + devfs_fpdrop(fp); +} + /* * Construct the fully qualified path name relative to the mountpoint */ @@ -374,8 +466,12 @@ devfs_close(struct vop_close_args *ap) static int devfs_close_f(struct file *fp, struct thread *td) { + int error; - return (vnops.fo_close(fp, td)); + curthread->td_fpop = fp; + error = vnops.fo_close(fp, td); + curthread->td_fpop = NULL; + return (error); } /* ARGSUSED */ @@ -472,6 +568,7 @@ devfs_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, struc if (com == FIODTYPE) { *(int *)data = dsw->d_flags & D_TYPEMASK; + td->td_fpop = NULL; dev_relthread(dev); return (0); } else if (com == FIODGNAME) { @@ -482,10 +579,12 @@ devfs_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, struc error = EINVAL; else error = copyout(p, fgn->buf, i); + td->td_fpop = NULL; dev_relthread(dev); return (error); } error = dsw->d_ioctl(dev, com, data, fp->f_flag, td); + td->td_fpop = NULL; dev_relthread(dev); if (error == ENOIOCTL) error = ENOTTY; @@ -529,6 +628,7 @@ devfs_kqfilter_f(struct file *fp, struct knote *kn) if (error) return (error); error = dsw->d_kqfilter(dev, kn); + curthread->td_fpop = NULL; dev_relthread(dev); return (error); } @@ -766,10 +866,15 @@ devfs_open(struct vop_open_args *ap) VOP_UNLOCK(vp, 0); + if (fp != NULL) { + td->td_fpop = fp; + fp->f_data = dev; + } if (dsw->d_fdopen != NULL) error = dsw->d_fdopen(dev, ap->a_mode, td, fp); else error = dsw->d_open(dev, ap->a_mode, S_IFCHR, td); + td->td_fpop = NULL; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); @@ -825,6 +930,7 @@ devfs_poll_f(struct file *fp, int events, struct ucred *cred, struct thread *td) if (error) return (error); error = dsw->d_poll(dev, events, td); + curthread->td_fpop = NULL; dev_relthread(dev); return(error); } @@ -862,6 +968,7 @@ devfs_read_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, st error = dsw->d_read(dev, uio, ioflag); if (uio->uio_resid != resid || (error == 0 && resid != 0)) vfs_timestamp(&dev->si_atime); + curthread->td_fpop = NULL; dev_relthread(dev); if ((flags & FOF_OFFSET) == 0) @@ -1298,6 +1405,7 @@ devfs_write_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, s vfs_timestamp(&dev->si_ctime); dev->si_mtime = dev->si_ctime; } + curthread->td_fpop = NULL; dev_relthread(dev); if ((flags & FOF_OFFSET) == 0) diff --git a/sys/kern/kern_conf.c b/sys/kern/kern_conf.c index f8e7a10..0e4aa22 100644 --- a/sys/kern/kern_conf.c +++ b/sys/kern/kern_conf.c @@ -839,6 +839,7 @@ static void destroy_devl(struct cdev *dev) { struct cdevsw *csw; + struct cdev_privdata *p, *p1; mtx_assert(&devmtx, MA_OWNED); KASSERT(dev->si_flags & SI_NAMED, @@ -880,9 +881,15 @@ destroy_devl(struct cdev *dev) msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10); } - mtx_unlock(&devmtx); + dev_unlock(); notify_destroy(dev); - mtx_lock(&devmtx); + mtx_lock(&cdevpriv_mtx); + LIST_FOREACH_SAFE(p, &dev->si_priv->cdp_fdpriv, cdpd_list, p1) { + devfs_destroy_cdevpriv(p); + mtx_lock(&cdevpriv_mtx); + } + mtx_unlock(&cdevpriv_mtx); + dev_lock(); dev->si_drv1 = 0; dev->si_drv2 = 0; diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c index bdc6d78..cbb7653 100644 --- a/sys/kern/kern_descrip.c +++ b/sys/kern/kern_descrip.c @@ -2221,6 +2221,12 @@ _fdrop(struct file *fp, struct thread *td) panic("fdrop: count %d", fp->f_count); if (fp->f_ops != &badfileops) error = fo_close(fp, td); + /* + * The f_cdevpriv cannot be assigned non-NULL value while we + * are destroying the file. + */ + if (fp->f_cdevpriv != NULL) + devfs_fpdrop(fp); atomic_subtract_int(&openfiles, 1); crfree(fp->f_cred); uma_zfree(file_zone, fp); diff --git a/sys/sys/conf.h b/sys/sys/conf.h index 91c2efc..bd6aaf0 100644 --- a/sys/sys/conf.h +++ b/sys/sys/conf.h @@ -281,6 +281,12 @@ int unit2minor(int _unit); u_int minor2unit(u_int _minor); void setconf(void); +typedef void (*cdevpriv_dtr_t)(void *data); +int devfs_get_cdevpriv(void **datap); +int devfs_set_cdevpriv(void *priv, cdevpriv_dtr_t dtr); +void devfs_clear_cdevpriv(void); +void devfs_fpdrop(struct file *fp); /* XXX This is not public KPI */ + #define UID_ROOT 0 #define UID_BIN 3 #define UID_UUCP 66 diff --git a/sys/sys/file.h b/sys/sys/file.h index 0281d21..e3fdd60 100644 --- a/sys/sys/file.h +++ b/sys/sys/file.h @@ -104,6 +104,7 @@ struct fileops { * Below is the list of locks that protects members in struct file. * * (f) protected with mtx_lock(mtx_pool_find(fp)) + * (d) cdevpriv_mtx * none not locked */ @@ -121,6 +122,7 @@ struct file { */ int f_seqcount; /* Count of sequential accesses. */ off_t f_nextoff; /* next expected read/write offset. */ + struct cdev_privdata *f_cdevpriv; /* (d) Private data for the cdev. */ /* * DFLAG_SEEKABLE specific fields */ diff --git a/sys/sys/proc.h b/sys/sys/proc.h index c88bb92..fa10291 100644 --- a/sys/sys/proc.h +++ b/sys/sys/proc.h @@ -231,6 +231,7 @@ struct thread { u_long td_profil_addr; /* (k) Temporary addr until AST. */ u_int td_profil_ticks; /* (k) Temporary ticks until AST. */ char td_name[MAXCOMLEN + 1]; /* (*) Thread name. */ + struct file *td_fpop; /* (k) file referencing cdev under op */ #define td_endzero td_base_pri /* Copied during fork1() or thread_sched_upcall(). */ |