Hi,
In order to unlock flock(2), make writes to the f_iflags field of struct
file atomic; similar to recent changes to both struct file and process.
This also gets rid of the last kernel lock protected field in the scope
of struct file.
Comments? OK?
Index: kern/kern_descrip.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_descrip.c,v
retrieving revision 1.200
diff -u -p -r1.200 kern_descrip.c
--- kern/kern_descrip.c 26 Feb 2020 13:54:52 -0000 1.200
+++ kern/kern_descrip.c 5 Mar 2020 11:51:28 -0000
@@ -707,7 +707,7 @@ fdinsert(struct filedesc *fdp, int fd, i
mtx_enter(&fhdlk);
if ((fp->f_iflags & FIF_INSERTED) == 0) {
- fp->f_iflags |= FIF_INSERTED;
+ atomic_setbits_int(&fp->f_iflags, FIF_INSERTED);
if ((fq = fdp->fd_ofiles[0]) != NULL) {
LIST_INSERT_AFTER(fq, fp, f_list);
} else {
@@ -1317,7 +1317,7 @@ sys_flock(struct proc *p, void *v, regis
lf.l_len = 0;
if (how & LOCK_UN) {
lf.l_type = F_UNLCK;
- fp->f_iflags &= ~FIF_HASLOCK;
+ atomic_clearbits_int(&fp->f_iflags, FIF_HASLOCK);
error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
goto out;
}
@@ -1329,7 +1329,7 @@ sys_flock(struct proc *p, void *v, regis
error = EINVAL;
goto out;
}
- fp->f_iflags |= FIF_HASLOCK;
+ atomic_setbits_int(&fp->f_iflags, FIF_HASLOCK);
if (how & LOCK_NB)
error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK);
else
Index: kern/vfs_syscalls.c
===================================================================
RCS file: /cvs/src/sys/kern/vfs_syscalls.c,v
retrieving revision 1.342
diff -u -p -r1.342 vfs_syscalls.c
--- kern/vfs_syscalls.c 30 Jan 2020 15:36:11 -0000 1.342
+++ kern/vfs_syscalls.c 5 Mar 2020 11:51:28 -0000
@@ -1188,7 +1188,7 @@ doopenat(struct proc *p, int fd, const c
goto out;
}
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
- fp->f_iflags |= FIF_HASLOCK;
+ atomic_setbits_int(&fp->f_iflags, FIF_HASLOCK);
}
if (localtrunc) {
if ((fp->f_flag & FWRITE) == 0)
@@ -1457,7 +1457,7 @@ sys_fhopen(struct proc *p, void *v, regi
goto bad;
}
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
- fp->f_iflags |= FIF_HASLOCK;
+ atomic_setbits_int(&fp->f_iflags, FIF_HASLOCK);
}
VOP_UNLOCK(vp);
*retval = indx;
Index: sys/file.h
===================================================================
RCS file: /cvs/src/sys/sys/file.h,v
retrieving revision 1.60
diff -u -p -r1.60 file.h
--- sys/file.h 1 Feb 2020 08:57:27 -0000 1.60
+++ sys/file.h 5 Mar 2020 11:51:28 -0000
@@ -75,7 +75,6 @@ struct fileops {
* a atomic operations
* f per file `f_mtx'
* v vnode lock
- * k kernel lock
*/
struct file {
LIST_ENTRY(file) f_list;/* [F] list of active files */
@@ -86,7 +85,7 @@ struct file {
#define DTYPE_PIPE 3 /* pipe */
#define DTYPE_KQUEUE 4 /* event queue */
#define DTYPE_DMABUF 5 /* DMA buffer (for DRM) */
- int f_iflags; /* [k] internal flags */
+ u_int f_iflags; /* [a] internal flags */
int f_type; /* [I] descriptor type */
u_int f_count; /* [a] reference count */
struct ucred *f_cred; /* [I] credentials associated with descriptor */
Index: sys/sysctl.h
===================================================================
RCS file: /cvs/src/sys/sys/sysctl.h,v
retrieving revision 1.204
diff -u -p -r1.204 sysctl.h
--- sys/sysctl.h 16 Feb 2020 07:55:30 -0000 1.204
+++ sys/sysctl.h 5 Mar 2020 11:51:28 -0000
@@ -735,7 +735,7 @@ do {
\
struct kinfo_file {
uint64_t f_fileaddr; /* PTR: address of struct file */
uint32_t f_flag; /* UINT: flags (see fcntl.h) */
- uint32_t f_iflags; /* INT: internal flags */
+ uint32_t f_iflags; /* UINT: internal flags */
uint32_t f_type; /* INT: descriptor type */
uint32_t f_count; /* UINT: reference count */
uint32_t f_msgcount; /* UINT: references from msg queue */
