quota: add the option to not fail with EDQUOT in block
To simplify metadata tracking for delalloc writes, ext4
will simply claim metadata blocks at allocation time, without
first speculatively reserving the worst case and then freeing
what was not used.
To do this, we need a mechanism to track allocations in
the quota subsystem, but potentially allow that allocation
to actually go over quota.
This patch adds a DQUOT_SPACE_NOFAIL flag and function
variants for this purpose.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 8c40c07..df6832e 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -1494,6 +1494,7 @@
char warntype[MAXQUOTAS];
int warn = flags & DQUOT_SPACE_WARN;
int reserve = flags & DQUOT_SPACE_RESERVE;
+ int nofail = flags & DQUOT_SPACE_NOFAIL;
/*
* First test before acquiring mutex - solves deadlocks when we
@@ -1514,7 +1515,7 @@
continue;
ret = check_bdq(inode->i_dquot[cnt], number, !warn,
warntype+cnt);
- if (ret) {
+ if (ret && !nofail) {
spin_unlock(&dq_data_lock);
goto out_flush_warn;
}