libzfs: zpool_load_compat(): open feature file cloexec

As a bonus, this also passes the open flags into the open flags instead
of the mode (it worked by accident because O_RDONLY is 0),
correctly detects a failed map,
and prefaults the entire file since we're always writing to every page

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11993
This commit is contained in:
наб 2021-04-29 22:21:41 +02:00 committed by Brian Behlendorf
parent 36e8abee95
commit 8bc357ba92

View File

@ -4812,14 +4812,14 @@ zpool_load_compat(const char *compat, boolean_t *features, char *report,
file != NULL;
file = strtok_r(NULL, ",", &ps)) {
boolean_t l_features[SPA_FEATURES];
boolean_t l_features[SPA_FEATURES] = {B_FALSE};
enum { Z_SYSCONF, Z_DATA } source;
/* try sysconfdir first, then datadir */
source = Z_SYSCONF;
if ((featfd = openat(sdirfd, file, 0, O_RDONLY)) < 0) {
featfd = openat(ddirfd, file, 0, O_RDONLY);
if ((featfd = openat(sdirfd, file, O_RDONLY | O_CLOEXEC)) < 0) {
featfd = openat(ddirfd, file, O_RDONLY | O_CLOEXEC);
source = Z_DATA;
}
@ -4835,13 +4835,18 @@ zpool_load_compat(const char *compat, boolean_t *features, char *report,
continue;
}
#if !defined(MAP_POPULATE) && defined(MAP_PREFAULT_READ)
#define MAP_POPULATE MAP_PREFAULT_READ
#elif !defined(MAP_POPULATE)
#define MAP_POPULATE 0
#endif
/* private mmap() so we can strtok safely */
fc = (char *)mmap(NULL, fs.st_size,
PROT_READ|PROT_WRITE, MAP_PRIVATE, featfd, 0);
PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_POPULATE, featfd, 0);
(void) close(featfd);
/* map ok, and last character == newline? */
if (fc < 0 || fc[fs.st_size - 1] != '\n') {
if (fc == MAP_FAILED || fc[fs.st_size - 1] != '\n') {
(void) munmap((void *) fc, fs.st_size);
strlcat(err_badfile, file, ZFS_MAXPROPLEN);
strlcat(err_badfile, " ", ZFS_MAXPROPLEN);
@ -4851,9 +4856,6 @@ zpool_load_compat(const char *compat, boolean_t *features, char *report,
ret_nofiles = B_FALSE;
for (uint_t i = 0; i < SPA_FEATURES; i++)
l_features[i] = B_FALSE;
/* replace last char with NUL to ensure we have a delimiter */
fc[fs.st_size - 1] = '\0';