Add a stat counter of culling events whereby the cache backend culls a file
to make space (when asked by cachefilesd in this case) and display in
/proc/fs/fscache/stats.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: linux-cachefs@xxxxxxxxxx
---
fs/cachefiles/namei.c | 1 +
fs/fscache/stats.c | 7 +++++--
include/linux/fscache-cache.h | 3 +++
3 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 7e24a7a2234d..a651da35dcd0 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -803,6 +803,7 @@ int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
if (ret < 0)
goto error;
+ fscache_count_culled();
dput(victim);
_leave(" = 0");
return 0;
diff --git a/fs/fscache/stats.c b/fs/fscache/stats.c
index db2f4e225dd9..fc94e5e79f1c 100644
--- a/fs/fscache/stats.c
+++ b/fs/fscache/stats.c
@@ -46,6 +46,8 @@ atomic_t fscache_n_no_write_space;
EXPORT_SYMBOL(fscache_n_no_write_space);
atomic_t fscache_n_no_create_space;
EXPORT_SYMBOL(fscache_n_no_create_space);
+atomic_t fscache_n_culled;
+EXPORT_SYMBOL(fscache_n_culled);
/*
* display the general statistics
@@ -86,9 +88,10 @@ int fscache_stats_show(struct seq_file *m, void *v)
atomic_read(&fscache_n_relinquishes_retire),
atomic_read(&fscache_n_relinquishes_dropped));
- seq_printf(m, "NoSpace: nwr=%u ncr=%u\n",
+ seq_printf(m, "NoSpace: nwr=%u ncr=%u cull=%u\n",
atomic_read(&fscache_n_no_write_space),
- atomic_read(&fscache_n_no_create_space));
+ atomic_read(&fscache_n_no_create_space),
+ atomic_read(&fscache_n_culled));
seq_printf(m, "IO : rd=%u wr=%u\n",
atomic_read(&fscache_n_read),
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index 1d7d43171243..7665bcab945e 100644
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -188,15 +188,18 @@ extern atomic_t fscache_n_read;
extern atomic_t fscache_n_write;
extern atomic_t fscache_n_no_write_space;
extern atomic_t fscache_n_no_create_space;
+extern atomic_t fscache_n_culled;
#define fscache_count_read() atomic_inc(&fscache_n_read)
#define fscache_count_write() atomic_inc(&fscache_n_write)
#define fscache_count_no_write_space() atomic_inc(&fscache_n_no_write_space)
#define fscache_count_no_create_space() atomic_inc(&fscache_n_no_create_space)
+#define fscache_count_culled() atomic_inc(&fscache_n_culled)
#else
#define fscache_count_read() do {} while(0)
#define fscache_count_write() do {} while(0)
#define fscache_count_no_write_space() do {} while(0)
#define fscache_count_no_create_space() do {} while(0)
+#define fscache_count_culled() do {} while(0)
#endif
#endif /* _LINUX_FSCACHE_CACHE_H */
