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;
}
diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h
index 9edd53c..f8dbeb0 100644
--- a/include/linux/quotaops.h
+++ b/include/linux/quotaops.h
@@ -11,6 +11,7 @@
#define DQUOT_SPACE_WARN 0x1
#define DQUOT_SPACE_RESERVE 0x2
+#define DQUOT_SPACE_NOFAIL 0x4
static inline struct quota_info *sb_dqopt(struct super_block *sb)
{
@@ -262,6 +263,12 @@
return __dquot_alloc_space(inode, nr, DQUOT_SPACE_WARN);
}
+static inline void dquot_alloc_space_nofail(struct inode *inode, qsize_t nr)
+{
+ __dquot_alloc_space(inode, nr, DQUOT_SPACE_WARN|DQUOT_SPACE_NOFAIL);
+ mark_inode_dirty(inode);
+}
+
static inline int dquot_alloc_space(struct inode *inode, qsize_t nr)
{
int ret;
@@ -277,6 +284,11 @@
return dquot_alloc_space_nodirty(inode, nr << inode->i_blkbits);
}
+static inline void dquot_alloc_block_nofail(struct inode *inode, qsize_t nr)
+{
+ dquot_alloc_space_nofail(inode, nr << inode->i_blkbits);
+}
+
static inline int dquot_alloc_block(struct inode *inode, qsize_t nr)
{
return dquot_alloc_space(inode, nr << inode->i_blkbits);