Differential D18617 Diff 79845 head/sys/kern/kern_descrip.c

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head/sys/kern/kern_descrip.c

Show First 20 Lines • Show All 1,795 Lines • ▼ Show 20 Lines	fdgrowtable(struct filedesc *fdp, int nfd)
/*		/*
* Make sure that ntable is correctly initialized before we replace		* Make sure that ntable is correctly initialized before we replace
* fd_files poiner. Otherwise fget_unlocked() may see inconsistent		* fd_files poiner. Otherwise fget_unlocked() may see inconsistent
* data.		* data.
*/		*/
atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable);		atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable);

/*		/*
* Do not free the old file table, as some threads may still		* Free the old file table when not shared by other threads or processes.
* reference entries within it. Instead, place it on a freelist		* The old file table is considered to be shared when either are true:
		* - The process has more than one thread.
		* - The file descriptor table has been shared via fdshare().
		*
		* When shared, the old file table will be placed on a freelist
* which will be processed when the struct filedesc is released.		* which will be processed when the struct filedesc is released.
*		*
* Note that if onfiles == NDFILE, we're dealing with the original		* Note that if onfiles == NDFILE, we're dealing with the original
* static allocation contained within (struct filedesc0 *)fdp,		* static allocation contained within (struct filedesc0 *)fdp,
* which must not be freed.		* which must not be freed.
*/		*/
if (onfiles > NDFILE) {		if (onfiles > NDFILE) {
		if (curproc->p_numthreads == 1 && fdp->fd_refcnt == 1)
		free(otable, M_FILEDESC);
		else {
ft = (struct freetable *)&otable->fdt_ofiles[onfiles];		ft = (struct freetable *)&otable->fdt_ofiles[onfiles];
fdp0 = (struct filedesc0 *)fdp;		fdp0 = (struct filedesc0 *)fdp;
ft->ft_table = otable;		ft->ft_table = otable;
SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next);		SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next);
		}
}		}
/*		/*
* The map does not have the same possibility of threads still		* The map does not have the same possibility of threads still
* holding references to it. So always free it as long as it		* holding references to it. So always free it as long as it
* does not reference the original static allocation.		* does not reference the original static allocation.
*/		*/
if (NDSLOTS(onfiles) > NDSLOTS(NDFILE))		if (NDSLOTS(onfiles) > NDSLOTS(NDFILE))
free(omap, M_FILEDESC);		free(omap, M_FILEDESC);
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