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When cleaning up from failed adv locking and checking for write, do

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not call VOP_CLOSE() manually.  Instead, delegate the close to
fo_close() performed as part of the fdrop() on the file failed to
open.  For this, finish constructing file on error, in particular, set
f_vnode and f_ops.

Forcibly resetting f_ops to badfileops disabled additional cleanups
performed by fo_close() for some file types, in this case it was noted
that cdevpriv data was corrupted.  Since fo_close() call must be
enabled for some file types, it makes more sense to enable it for all
files opened through vn_open_cred().

In collaboration with:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
This commit is contained in:
Konstantin Belousov 2016-01-17 08:40:51 +00:00
parent aeace3c33c
commit ce958bdefe
2 changed files with 17 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
sys/kern/vfs_vnops.c
View File

@ -299,10 +299,9 @@ int
vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
struct thread *td, struct file *fp)
{
struct mount *mp;
accmode_t accmode;
struct flock lf;
int error, have_flock, lock_flags, type;
int error, lock_flags, type;
if (vp->v_type == VLNK)
return (EMLINK);
@ -365,10 +364,12 @@ vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
if ((fmode & FNONBLOCK) == 0)
type |= F_WAIT;
error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type);
have_flock = (error == 0);
if (error == 0)
fp->f_flag |= FHASLOCK;
vn_lock(vp, lock_flags | LK_RETRY);
if (error == 0 && vp->v_iflag & VI_DOOMED)
error = ENOENT;
/*
* Another thread might have used this vnode as an
* executable while the vnode lock was dropped.
@ -377,34 +378,24 @@ vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
*/
if (error == 0 && accmode & VWRITE)
error = vn_writechk(vp);
if (error) {
VOP_UNLOCK(vp, 0);
if (have_flock) {
lf.l_whence = SEEK_SET;
lf.l_start = 0;
lf.l_len = 0;
lf.l_type = F_UNLCK;
(void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf,
F_FLOCK);
if (error != 0) {
fp->f_flag |= FOPENFAILED;
fp->f_vnode = vp;
if (fp->f_ops == &badfileops) {
fp->f_type = DTYPE_VNODE;
fp->f_ops = &vnops;
}
vn_start_write(vp, &mp, V_WAIT);
vn_lock(vp, lock_flags | LK_RETRY);
(void)VOP_CLOSE(vp, fmode, cred, td);
vn_finished_write(mp);
/* Prevent second close from fdrop()->vn_close(). */
if (fp != NULL)
fp->f_ops= &badfileops;
return (error);
vref(vp);
}
fp->f_flag |= FHASLOCK;
}
if (fmode & FWRITE) {
if (error == 0 && fmode & FWRITE) {
VOP_ADD_WRITECOUNT(vp, 1);
CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
__func__, vp, vp->v_writecount);
}
ASSERT_VOP_LOCKED(vp, "vn_open_vnode");
return (0);
return (error);
}
/*
@ -449,7 +440,7 @@ vn_close(vp, flags, file_cred, td)
vn_start_write(vp, &mp, V_WAIT);
vn_lock(vp, lock_flags | LK_RETRY);
if (flags & FWRITE) {
if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) {
VNASSERT(vp->v_writecount > 0, vp,
("vn_close: negative writecount"));
VOP_ADD_WRITECOUNT(vp, -1);

2
sys/sys/fcntl.h
View File

@ -142,6 +142,8 @@ typedef __pid_t pid_t;
/* Only for devfs d_close() flags. */
#define FLASTCLOSE O_DIRECTORY
#define FREVOKE O_VERIFY
/* Only for fo_close() from half-succeeded open */
#define FOPENFAILED O_TTY_INIT
/* convert from open() flags to/from fflags; convert O_RD/WR to FREAD/FWRITE */
#define FFLAGS(oflags) ((oflags) & O_EXEC ? (oflags) : (oflags) + 1)