Speed up pw operations that edit /etc/group or /etc/passwd

r285050 fixed a bug in pw that could lead to /etc/passwd or /etc/group
corruption on power loss. However, it fixed it by opening those files with
O_SYNC, which is very slow, especially on ZFS. This change replaces O_SYNC
with appropriately placed fsync()s instead, which is much faster. Using a
ZFS tmpdir, the time to run pw's kyua tests drops from 245s to 35s.

Reviewed by:	allanjude, bapt, vangyzen, garga
Tested on pfSense by:	garga
MFC after:	4 weeks
Sponsored by:	Spectra Logic Corp
Differential Revision:	https://reviews.freebsd.org/D8319
This commit is contained in:
Alan Somers 2016-11-18 16:07:08 +00:00
parent 34cd8ebdcf
commit cbaba16b23
5 changed files with 5 additions and 2 deletions

View File

@ -141,7 +141,7 @@ gr_tmp(int mfd)
errno = ENAMETOOLONG; errno = ENAMETOOLONG;
return (-1); return (-1);
} }
if ((tfd = mkostemp(tempname, O_SYNC)) == -1) if ((tfd = mkostemp(tempname, 0)) == -1)
return (-1); return (-1);
if (mfd != -1) { if (mfd != -1) {
while ((nr = read(mfd, buf, sizeof(buf))) > 0) while ((nr = read(mfd, buf, sizeof(buf))) > 0)

View File

@ -225,7 +225,7 @@ pw_tmp(int mfd)
errno = ENAMETOOLONG; errno = ENAMETOOLONG;
return (-1); return (-1);
} }
if ((tfd = mkostemp(tempname, O_SYNC)) == -1) if ((tfd = mkostemp(tempname, 0)) == -1)
return (-1); return (-1);
if (mfd != -1) { if (mfd != -1) {
while ((nr = read(mfd, buf, sizeof(buf))) > 0) while ((nr = read(mfd, buf, sizeof(buf))) > 0)

View File

@ -77,6 +77,7 @@ gr_update(struct group * grp, char const * group)
close(tfd); close(tfd);
err(1, "gr_copy()"); err(1, "gr_copy()");
} }
fsync(tfd);
close(tfd); close(tfd);
if (gr_mkdb() == -1) { if (gr_mkdb() == -1) {
gr_fini(); gr_fini();

View File

@ -67,6 +67,7 @@ pw_nisupdate(const char * path, struct passwd * pwd, char const * user)
close(tfd); close(tfd);
err(1, "pw_copy()"); err(1, "pw_copy()");
} }
fsync(tfd);
close(tfd); close(tfd);
if (chmod(pw_tempname(), 0644) == -1) if (chmod(pw_tempname(), 0644) == -1)
err(1, "chmod()"); err(1, "chmod()");

View File

@ -114,6 +114,7 @@ pw_update(struct passwd * pwd, char const * user)
close(tfd); close(tfd);
err(1, "pw_copy()"); err(1, "pw_copy()");
} }
fsync(tfd);
close(tfd); close(tfd);
/* /*
* in case of deletion of a user, the whole database * in case of deletion of a user, the whole database