libzfs_core: simplify max_pipe_buffer(), return new max

We do still check and only optionally set because all F_SETPIPE_SZ
directives reallocate the pipe buffer

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13133
This commit is contained in:
наб 2022-02-20 20:17:22 +01:00 committed by Brian Behlendorf
parent 8a3d77358a
commit fbbea09db9

View File

@ -91,6 +91,9 @@
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/zfs_ioctl.h>
#if __FreeBSD__
#define BIG_PIPE_SIZE (64 * 1024) /* From sys/pipe.h */
#endif
static int g_fd = -1;
static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
@ -586,27 +589,31 @@ lzc_get_holds(const char *snapname, nvlist_t **holdsp)
return (lzc_ioctl(ZFS_IOC_GET_HOLDS, snapname, NULL, holdsp));
}
static void
static unsigned int
max_pipe_buffer(int infd)
{
#if __linux__
FILE *procf = fopen("/proc/sys/fs/pipe-max-size", "re");
static unsigned int max;
if (max == 0) {
max = 1048576; /* fs/pipe.c default */
FILE *procf = fopen("/proc/sys/fs/pipe-max-size", "re");
if (procf != NULL) {
unsigned long max_psize;
long cur_psize;
if (fscanf(procf, "%lu", &max_psize) > 0) {
cur_psize = fcntl(infd, F_GETPIPE_SZ);
if (cur_psize > 0 &&
max_psize > (unsigned long) cur_psize)
fcntl(infd, F_SETPIPE_SZ,
max_psize);
if (fscanf(procf, "%u", &max) <= 0) {
/* ignore error: max untouched if parse fails */
}
fclose(procf);
}
}
unsigned int cur = fcntl(infd, F_GETPIPE_SZ);
if (cur < max && fcntl(infd, F_SETPIPE_SZ, max) != -1)
cur = max;
return (cur);
#else
/* FreeBSD automatically resizes */
(void) infd;
return (BIG_PIPE_SIZE);
#endif
}
@ -843,7 +850,7 @@ recv_impl(const char *snapname, nvlist_t *recvdprops, nvlist_t *localprops,
if (fstat(input_fd, &sb) == -1)
return (errno);
if (S_ISFIFO(sb.st_mode))
max_pipe_buffer(input_fd);
(void) max_pipe_buffer(input_fd);
/*
* The begin_record is normally a non-byteswapped BEGIN record.