I'm always wonder why do we have to allocate space for quota-file
as normal file. Because of this we have to grab i_mutex on each
quota write. And still getting in to risk of ENOSPC. The later is
really annoying issue for me(when i run fsstress tests).
Let's live the i_mutex's story for another day and consider the
simplest one. Why don't we preallocate a space for quota file
during creation. In fact we may imagine some reasonable quota-file
size expectation (65538 * 64) = 4Mb, At least this may be sufficient
for most use-cases.
>From ef72d4ad7d23db734a7ce74b350cdd47a594130b Mon Sep 17 00:00:00 2001
From: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
Date: Sun, 7 Mar 2010 20:08:51 +0300
Subject: [PATCH] quota: prealloc space for new quota file.
Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
---
convertquota.c | 4 ++--
quotacheck.c | 2 +-
quotaio.c | 15 ++++++++++++++-
quotaio.h | 2 +-
4 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/convertquota.c b/convertquota.c
index 1572cb9..2304be6 100644
--- a/convertquota.c
+++ b/convertquota.c
@@ -287,7 +287,7 @@ static int convert_format(int type, struct mntent *mnt)
type2name(type), mnt->mnt_dir);
return -1;
}
- if (!(qn = new_io(mnt, type, QF_VFSV0))) {
+ if (!(qn = new_io(mnt, type, QF_VFSV0, 8192*1024))) {
errstr(_("Cannot create file for %ss for new format on %s: %s\n"),
type2name(type), mnt->mnt_dir, strerror(errno));
end_io(qo);
@@ -320,7 +320,7 @@ static int convert_endian(int type, struct mntent *mnt)
close(ofd);
return -1;
}
- if (!(qn = new_io(mnt, type, QF_VFSV0))) {
+ if (!(qn = new_io(mnt, type, QF_VFSV0, 8192*1024))) {
errstr(_("Cannot create file for %ss for new format on %s: %s\n"),
type2name(type), mnt->mnt_dir, strerror(errno));
close(ofd);
diff --git a/quotacheck.c b/quotacheck.c
index b5f7e2e..2b49820 100644
--- a/quotacheck.c
+++ b/quotacheck.c
@@ -794,7 +794,7 @@ static int dump_to_file(struct mntent *mnt, int type)
struct quota_handle *h;
debug(FL_DEBUG, _("Dumping gathered data for %ss.\n"), type2name(type));
- if (!(h = new_io(mnt, type, cfmt))) {
+ if (!(h = new_io(mnt, type, cfmt, 8192*1024))) {
errstr(_("Cannot initialize IO on new quotafile: %s\n"),
strerror(errno));
return -1;
diff --git a/quotaio.c b/quotaio.c
index d74a37d..540e89b 100644
--- a/quotaio.c
+++ b/quotaio.c
@@ -166,7 +166,7 @@ out_handle:
/*
* Create new quotafile of specified format on given filesystem
*/
-struct quota_handle *new_io(struct mntent *mnt, int type, int fmt)
+struct quota_handle *new_io(struct mntent *mnt, int type, int fmt, int prealloc)
{
char *qfname;
int fd;
@@ -212,6 +212,19 @@ struct quota_handle *new_io(struct mntent *mnt, int type, int fmt)
free(h);
goto out_fd;
}
+ if (prealloc) {
+ char zbuf[4096];
+ int len, ret;
+ memset(zbuf, 0, sizeof(zbuf));
+ while (prealloc) {
+ len = (sizeof(zbuf) < prealloc) ? sizeof(zbuf) : prealloc;
+ ret = write(fd, zbuf, len);
+ if (ret < 0)
+ goto out_fd;
+ prealloc -= len;
+ }
+ lseek(fd, 0, SEEK_SET);
+ }
return h;
out_fd:
close(fd);
diff --git a/quotaio.h b/quotaio.h
index f6eef50..c66db43 100644
--- a/quotaio.h
+++ b/quotaio.h
@@ -169,7 +169,7 @@ static inline void mark_quotafile_info_dirty(struct quota_handle *h)
struct quota_handle *init_io(struct mntent *mnt, int type, int fmt, int flags);
/* Create new quotafile of specified format on given filesystem */
-struct quota_handle *new_io(struct mntent *mnt, int type, int fmt);
+struct quota_handle *new_io(struct mntent *mnt, int type, int fmt, int prealloc);
/* Close quotafile */
int end_io(struct quota_handle *h);
--
1.6.3.3
