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Replace direct atomic operation for the file refcount witht the

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refcount interface.
It also introduces the correct usage of memory barriers, as sometimes
fdrop() and fhold() are used with shared locks, which don't use any
release barrier.
This commit is contained in:
attilio 2008-05-25 14:57:43 +00:00
parent 4789bb5715
commit 4d240aa98e
2 changed files with 7 additions and 5 deletions
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4
sys/kern/kern_descrip.c
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@ -1449,9 +1449,9 @@ falloc(struct thread *td, struct file **resultfp, int *resultfd)
* descriptor to the list of open files at that point, otherwise * descriptor to the list of open files at that point, otherwise
* put it at the front of the list of open files. * put it at the front of the list of open files.
*/ */
fp->f_count = 1; refcount_init(&fp->f_count, 1);
if (resultfp) if (resultfp)
fp->f_count++; fhold(fp);
fp->f_cred = crhold(td->td_ucred); fp->f_cred = crhold(td->td_ucred);
fp->f_ops = &badfileops; fp->f_ops = &badfileops;
fp->f_data = NULL; fp->f_data = NULL;

8
sys/sys/file.h
View File

@ -39,6 +39,7 @@
#include <sys/unistd.h> #include <sys/unistd.h>
#else #else
#include <sys/queue.h> #include <sys/queue.h>
#include <sys/refcount.h>
#include <sys/_lock.h> #include <sys/_lock.h>
#include <sys/_mutex.h> #include <sys/_mutex.h>
@ -116,7 +117,7 @@ struct file {
short f_type; /* descriptor type */ short f_type; /* descriptor type */
short f_vnread_flags; /* (f) Sleep lock for f_offset */ short f_vnread_flags; /* (f) Sleep lock for f_offset */
volatile u_int f_flag; /* see fcntl.h */ volatile u_int f_flag; /* see fcntl.h */
volatile int f_count; /* reference count */ volatile u_int f_count; /* reference count */
/* /*
* DTYPE_VNODE specific fields. * DTYPE_VNODE specific fields.
*/ */
@ -196,9 +197,10 @@ int fgetvp_write(struct thread *td, int fd, struct vnode **vpp);
int fgetsock(struct thread *td, int fd, struct socket **spp, u_int *fflagp); int fgetsock(struct thread *td, int fd, struct socket **spp, u_int *fflagp);
void fputsock(struct socket *sp); void fputsock(struct socket *sp);
#define fhold(fp) atomic_add_int(&(fp)->f_count, 1) #define fhold(fp) \
(refcount_acquire(&(fp)->f_count))
#define fdrop(fp, td) \ #define fdrop(fp, td) \
(atomic_fetchadd_int(&(fp)->f_count, -1) <= 1 ? _fdrop((fp), (td)) : 0) (refcount_release(&(fp)->f_count) ? _fdrop((fp), (td)) : 0)
static __inline fo_rdwr_t fo_read; static __inline fo_rdwr_t fo_read;
static __inline fo_rdwr_t fo_write; static __inline fo_rdwr_t fo_write;