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Revert "ANDROID: Incremental fs: RCU locks instead of mutex for pending_reads."

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This reverts commit 883c150ca9.

Set incfs back to rvc shipping incfs

Bug: 178509184
Test: incfs_test passes
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Change-Id: I492c8cacd213df35c093a582a7f1c598913db104
This commit is contained in:
Paul Lawrence
2021-01-26 13:31:18 -08:00
parent 8d04cc8cc0
commit a190069bc3
2 changed files with 27 additions and 51 deletions
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69
fs/incfs/data_mgmt.c
View File

@@ -40,11 +40,11 @@ struct mount_info *incfs_alloc_mount_info(struct super_block *sb,
mi->mi_owner = get_current_cred();
path_get(&mi->mi_backing_dir_path);
mutex_init(&mi->mi_dir_struct_mutex);
mutex_init(&mi->mi_pending_reads_mutex);
init_waitqueue_head(&mi->mi_pending_reads_notif_wq);
init_waitqueue_head(&mi->mi_log.ml_notif_wq);
INIT_DELAYED_WORK(&mi->mi_log.ml_wakeup_work, log_wake_up_all);
spin_lock_init(&mi->mi_log.rl_lock);
spin_lock_init(&mi->pending_read_lock);
INIT_LIST_HEAD(&mi->mi_reads_list_head);
error = incfs_realloc_mount_info(mi, options);
@@ -109,6 +109,7 @@ void incfs_free_mount_info(struct mount_info *mi)
dput(mi->mi_index_dir);
path_put(&mi->mi_backing_dir_path);
mutex_destroy(&mi->mi_dir_struct_mutex);
mutex_destroy(&mi->mi_pending_reads_mutex);
put_cred(mi->mi_owner);
kfree(mi->mi_log.rl_ring_buf);
kfree(mi->log_xattr);
@@ -755,29 +756,19 @@ static struct pending_read *add_pending_read(struct data_file *df,
result->block_index = block_index;
result->timestamp_us = ktime_to_us(ktime_get());
spin_lock(&mi->pending_read_lock);
mutex_lock(&mi->mi_pending_reads_mutex);
result->serial_number = ++mi->mi_last_pending_read_number;
mi->mi_pending_reads_count++;
list_add_rcu(&result->mi_reads_list, &mi->mi_reads_list_head);
list_add_rcu(&result->segment_reads_list, &segment->reads_list_head);
spin_unlock(&mi->pending_read_lock);
list_add(&result->mi_reads_list, &mi->mi_reads_list_head);
list_add(&result->segment_reads_list, &segment->reads_list_head);
mutex_unlock(&mi->mi_pending_reads_mutex);
wake_up_all(&mi->mi_pending_reads_notif_wq);
return result;
}
static void free_pending_read_entry(struct rcu_head *entry)
{
struct pending_read *read;
read = container_of(entry, struct pending_read, rcu);
kfree(read);
}
/* Notifies a given data file that pending read is completed. */
static void remove_pending_read(struct data_file *df, struct pending_read *read)
{
@@ -791,17 +782,14 @@ static void remove_pending_read(struct data_file *df, struct pending_read *read)
mi = df->df_mount_info;
spin_lock(&mi->pending_read_lock);
list_del_rcu(&read->mi_reads_list);
list_del_rcu(&read->segment_reads_list);
mutex_lock(&mi->mi_pending_reads_mutex);
list_del(&read->mi_reads_list);
list_del(&read->segment_reads_list);
mi->mi_pending_reads_count--;
mutex_unlock(&mi->mi_pending_reads_mutex);
spin_unlock(&mi->pending_read_lock);
/* Don't free. Wait for readers */
call_rcu(&read->rcu, free_pending_read_entry);
kfree(read);
}
static void notify_pending_reads(struct mount_info *mi,
@@ -811,13 +799,13 @@ static void notify_pending_reads(struct mount_info *mi,
struct pending_read *entry = NULL;
/* Notify pending reads waiting for this block. */
rcu_read_lock();
list_for_each_entry_rcu(entry, &segment->reads_list_head,
mutex_lock(&mi->mi_pending_reads_mutex);
list_for_each_entry(entry, &segment->reads_list_head,
segment_reads_list) {
if (entry->block_index == index)
set_read_done(entry);
}
rcu_read_unlock();
mutex_unlock(&mi->mi_pending_reads_mutex);
wake_up_all(&segment->new_data_arrival_wq);
}
@@ -881,6 +869,7 @@ static int wait_for_data_block(struct data_file *df, int block_index,
/* Woke up, the pending read is no longer needed. */
remove_pending_read(df, read);
read = NULL;
if (wait_res == 0) {
/* Wait has timed out */
@@ -1303,14 +1292,10 @@ bool incfs_fresh_pending_reads_exist(struct mount_info *mi, int last_number)
{
bool result = false;
/*
* We could probably get away with spin locks here;
* if we use atomic_read() on both these variables.
*/
spin_lock(&mi->pending_read_lock);
mutex_lock(&mi->mi_pending_reads_mutex);
result = (mi->mi_last_pending_read_number > last_number) &&
(mi->mi_pending_reads_count > 0);
spin_unlock(&mi->pending_read_lock);
mutex_unlock(&mi->mi_pending_reads_mutex);
return result;
}
@@ -1320,7 +1305,6 @@ int incfs_collect_pending_reads(struct mount_info *mi, int sn_lowerbound,
{
int reported_reads = 0;
struct pending_read *entry = NULL;
bool result = false;
if (!mi)
return -EFAULT;
@@ -1328,19 +1312,13 @@ int incfs_collect_pending_reads(struct mount_info *mi, int sn_lowerbound,
if (reads_size <= 0)
return 0;
spin_lock(&mi->pending_read_lock);
mutex_lock(&mi->mi_pending_reads_mutex);
result = ((mi->mi_last_pending_read_number <= sn_lowerbound)
|| (mi->mi_pending_reads_count == 0));
if (mi->mi_last_pending_read_number <= sn_lowerbound
|| mi->mi_pending_reads_count == 0)
goto unlock;
spin_unlock(&mi->pending_read_lock);
if (result)
return reported_reads;
rcu_read_lock();
list_for_each_entry_rcu(entry, &mi->mi_reads_list_head, mi_reads_list) {
list_for_each_entry(entry, &mi->mi_reads_list_head, mi_reads_list) {
if (entry->serial_number <= sn_lowerbound)
continue;
@@ -1355,7 +1333,8 @@ int incfs_collect_pending_reads(struct mount_info *mi, int sn_lowerbound,
break;
}
rcu_read_unlock();
unlock:
mutex_unlock(&mi->mi_pending_reads_mutex);
return reported_reads;
}

7
fs/incfs/data_mgmt.h
View File

@@ -10,7 +10,6 @@
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <linux/completion.h>
#include <linux/wait.h>
#include <crypto/hash.h>
@@ -124,13 +123,13 @@ struct mount_info {
wait_queue_head_t mi_pending_reads_notif_wq;
/*
* Protects - RCU safe:
* Protects:
* - reads_list_head
* - mi_pending_reads_count
* - mi_last_pending_read_number
* - data_file_segment.reads_list_head
*/
spinlock_t pending_read_lock;
struct mutex mi_pending_reads_mutex;
/* List of active pending_read objects */
struct list_head mi_reads_list_head;
@@ -176,8 +175,6 @@ struct pending_read {
struct list_head mi_reads_list;
struct list_head segment_reads_list;
struct rcu_head rcu;
};
struct data_file_segment {