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Differential D26041 Diff 78208 head/usr.bin/xinstall/xinstall.c

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head/usr.bin/xinstall/xinstall.c

Show First 20 Lines • Show All 142 Lines • ▼ Show 20 Lines
static void do_symlink(const char *, const char *, const struct stat *); static void do_symlink(const char *, const char *, const struct stat *);
static void makelink(const char *, const char *, const struct stat *); static void makelink(const char *, const char *, const struct stat *);
static void install(const char *, const char *, u_long, u_int); static void install(const char *, const char *, u_long, u_int);
static void install_dir(char *); static void install_dir(char *);
static void metadata_log(const char *, const char *, struct timespec *, static void metadata_log(const char *, const char *, struct timespec *,
const char *, const char *, off_t); const char *, const char *, off_t);
static int parseid(const char *, id_t *); static int parseid(const char *, id_t *);
static int strip(const char *, int, const char *, char **); static int strip(const char *, int, const char *, char **);
static int trymmap(int); static int trymmap(size_t);
static void usage(void); static void usage(void);
int int
main(int argc, char *argv[]) main(int argc, char *argv[])
{ {
struct stat from_sb, to_sb; struct stat from_sb, to_sb;
mode_t *set; mode_t *set;
u_long fset; u_long fset;
▲ Show 20 Lines • Show All 922 Lines • ▼ Show 20 Lines if (from_len != to_len)
return 1; return 1;
do_digest = (digesttype != DIGEST_NONE && dresp != NULL && do_digest = (digesttype != DIGEST_NONE && dresp != NULL &&
*dresp == NULL); *dresp == NULL);
if (from_len <= MAX_CMP_SIZE) { if (from_len <= MAX_CMP_SIZE) {
if (do_digest) if (do_digest)
digest_init(&ctx); digest_init(&ctx);
done_compare = 0; done_compare = 0;
if (trymmap(from_fd) && trymmap(to_fd)) { if (trymmap(from_len) && trymmap(to_len)) {
p = mmap(NULL, from_len, PROT_READ, MAP_SHARED, p = mmap(NULL, from_len, PROT_READ, MAP_SHARED,
from_fd, (off_t)0); from_fd, (off_t)0);
if (p == MAP_FAILED) if (p == MAP_FAILED)
goto out; goto out;
q = mmap(NULL, from_len, PROT_READ, MAP_SHARED, q = mmap(NULL, from_len, PROT_READ, MAP_SHARED,
to_fd, (off_t)0); to_fd, (off_t)0);
if (q == MAP_FAILED) { if (q == MAP_FAILED) {
munmap(p, from_len); munmap(p, from_len);
▲ Show 20 Lines • Show All 144 Lines • ▼ Show 20 Linescopy(int from_fd, const char *from_name, int to_fd, const char *to_name,
/* Rewind file descriptors. */ /* Rewind file descriptors. */
if (lseek(from_fd, (off_t)0, SEEK_SET) == (off_t)-1) if (lseek(from_fd, (off_t)0, SEEK_SET) == (off_t)-1)
err(EX_OSERR, "lseek: %s", from_name); err(EX_OSERR, "lseek: %s", from_name);
if (lseek(to_fd, (off_t)0, SEEK_SET) == (off_t)-1) if (lseek(to_fd, (off_t)0, SEEK_SET) == (off_t)-1)
err(EX_OSERR, "lseek: %s", to_name); err(EX_OSERR, "lseek: %s", to_name);
digest_init(&ctx); digest_init(&ctx);
/*
* Mmap and write if less than 8M (the limit is so we don't totally
* trash memory on big files. This is really a minor hack, but it
* wins some CPU back.
*/
done_copy = 0; done_copy = 0;
if (size <= 8 * 1048576 && trymmap(from_fd) && if (trymmap((size_t)size) &&
(p = mmap(NULL, (size_t)size, PROT_READ, MAP_SHARED, (p = mmap(NULL, (size_t)size, PROT_READ, MAP_SHARED,
from_fd, (off_t)0)) != MAP_FAILED) { from_fd, (off_t)0)) != MAP_FAILED) {
nw = write(to_fd, p, size); nw = write(to_fd, p, size);
if (nw != size) { if (nw != size) {
serrno = errno; serrno = errno;
(void)unlink(to_name); (void)unlink(to_name);
if (nw >= 0) { if (nw >= 0) {
errx(EX_OSERR, errx(EX_OSERR,
▲ Show 20 Lines • Show All 252 Lines • ▼ Show 20 Lines" directory ...\n");
/* NOTREACHED */ /* NOTREACHED */
} }
/* /*
* trymmap -- * trymmap --
* return true (1) if mmap should be tried, false (0) if not. * return true (1) if mmap should be tried, false (0) if not.
*/ */
static int static int
trymmap(int fd) trymmap(size_t filesize)
{ {
/* /*
* The ifdef is for bootstrapping - f_fstypename doesn't exist in * This function existed to skip mmap() for NFS file systems whereas
* pre-Lite2-merge systems. * nowadays mmap() should be perfectly safe. Nevertheless, using mmap()
* only reduces the number of system calls if we need multiple read()
* syscalls, i.e. if the file size is > MAXBSIZE. However, mmap() is
* more expensive than read() so set the threshold at 4 fewer syscalls.
* Additionally, for larger file size mmap() can significantly increase
* the number of page faults, so avoid it in that case.
*
* Note: the 8MB limit is not based on any meaningful benchmarking
* results, it is simply reusing the same value that was used before
* and also matches bin/cp.
*
* XXX: Maybe we shouldn't bother with mmap() at all, since we use
* MAXBSIZE the syscall overhead of read() shouldn't be too high?
*/ */
#ifdef MFSNAMELEN return (filesize > 4 * MAXBSIZE && filesize < 8 * 1024 * 1024);
struct statfs stfs;
if (fstatfs(fd, &stfs) != 0)
return (0);
if (strcmp(stfs.f_fstypename, "ufs") == 0 ||
strcmp(stfs.f_fstypename, "cd9660") == 0)
return (1);
#endif
return (0);
} }