2020-01-06 18:20:45

by Trond Myklebust

Subject: [PATCH RESEND 4/6] nfsd: Remove unused constant NFSD_FILE_LRU_RESCAN

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfsd/filecache.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index e71af553c2ed..6b0ab43b0618 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -27,7 +27,6 @@
#define NFSD_FILE_HASH_SIZE (1 << NFSD_FILE_HASH_BITS)
#define NFSD_LAUNDRETTE_DELAY (2 * HZ)

-#define NFSD_FILE_LRU_RESCAN (0)
#define NFSD_FILE_SHUTDOWN (1)
#define NFSD_FILE_LRU_THRESHOLD (4096UL)
#define NFSD_FILE_LRU_LIMIT (NFSD_FILE_LRU_THRESHOLD << 2)
@@ -440,15 +439,13 @@ nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru,
goto out_skip;

if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags))
- goto out_rescan;
+ goto out_skip;

if (!test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags))
goto out_skip;

list_lru_isolate_move(lru, &nf->nf_lru, head);
return LRU_REMOVED;
-out_rescan:
- set_bit(NFSD_FILE_LRU_RESCAN, &nfsd_file_lru_flags);
out_skip:
return LRU_SKIP;
}
--
2.24.1

2020-01-06 18:20:45

by Trond Myklebust

Subject: [PATCH RESEND 5/6] nfsd: Schedule the laundrette regularly irrespective of file errors

Emsure we schedule the laundrette even if the struct file is carrying
file errors.

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfsd/filecache.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 6b0ab43b0618..4cef03a7726c 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -237,13 +237,6 @@ nfsd_file_check_write_error(struct nfsd_file *nf)
return filemap_check_wb_err(file->f_mapping, READ_ONCE(file->f_wb_err));
}

-static bool
-nfsd_file_in_use(struct nfsd_file *nf)
-{
- return nfsd_file_check_writeback(nf) ||
- nfsd_file_check_write_error(nf);
-}
-
static void
nfsd_file_do_unhash(struct nfsd_file *nf)
{
@@ -307,10 +300,9 @@ void
nfsd_file_put(struct nfsd_file *nf)
{
bool is_hashed = test_bit(NFSD_FILE_HASHED, &nf->nf_flags) != 0;
- bool unused = !nfsd_file_in_use(nf);

set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags);
- if (nfsd_file_put_noref(nf) == 1 && is_hashed && unused)
+ if (nfsd_file_put_noref(nf) == 1 && is_hashed)
nfsd_file_schedule_laundrette();
if (atomic_long_read(&nfsd_filecache_count) >= NFSD_FILE_LRU_LIMIT)
nfsd_file_gc();
--
2.24.1

2020-01-06 18:20:51

by Trond Myklebust

Subject: [PATCH RESEND 6/6] nfsd: Reduce the number of calls to nfsd_file_gc()

Don't call nfsd_file_gc() on every put of the reference in nfsd_file_put().
Instead, do it only when we're expecting the refcount to go to 1.

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfsd/filecache.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 4cef03a7726c..9c2b29e07975 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -282,27 +282,32 @@ nfsd_file_unhash_and_release_locked(struct nfsd_file *nf, struct list_head *disp
return true;
}

-static int
+static void
nfsd_file_put_noref(struct nfsd_file *nf)
{
- int count;
trace_nfsd_file_put(nf);

- count = atomic_dec_return(&nf->nf_ref);
- if (!count) {
+ if (atomic_dec_and_test(&nf->nf_ref)) {
WARN_ON(test_bit(NFSD_FILE_HASHED, &nf->nf_flags));
nfsd_file_free(nf);
}
- return count;
}

void
nfsd_file_put(struct nfsd_file *nf)
{
- bool is_hashed = test_bit(NFSD_FILE_HASHED, &nf->nf_flags) != 0;
+ bool is_hashed;

set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags);
- if (nfsd_file_put_noref(nf) == 1 && is_hashed)
+ if (atomic_read(&nf->nf_ref) > 2 || !nf->nf_file) {
+ nfsd_file_put_noref(nf);
+ return;
+ }
+
+ filemap_flush(nf->nf_file->f_mapping);
+ is_hashed = test_bit(NFSD_FILE_HASHED, &nf->nf_flags) != 0;
+ nfsd_file_put_noref(nf);
+ if (is_hashed)
nfsd_file_schedule_laundrette();
if (atomic_long_read(&nfsd_filecache_count) >= NFSD_FILE_LRU_LIMIT)
nfsd_file_gc();
--
2.24.1