Re: [f2fs-dev] [PATCH] f2fs: change i_compr_blocks of inode to atomic value
From: Chao Yu
Date: Wed Sep 02 2020 - 21:12:35 EST
On 2020/9/2 14:29, Daeho Jeong wrote:
From: Daeho Jeong <daehojeong@xxxxxxxxxx>
writepages() can be concurrently invoked for the same file by different
threads such as a thread fsyncing the file and a kworker kernel thread.
So, changing i_compr_blocks without protection is racy and we need to
protect it by changing it with atomic type value.
Signed-off-by: Daeho Jeong <daehojeong@xxxxxxxxxx>
---
fs/f2fs/f2fs.h | 15 +++++++++------
fs/f2fs/file.c | 18 ++++++++++--------
fs/f2fs/inode.c | 11 +++++++----
fs/f2fs/super.c | 1 +
4 files changed, 27 insertions(+), 18 deletions(-)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f60414805e05..633957e14944 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -801,7 +801,7 @@ struct f2fs_inode_info {
struct timespec64 i_disk_time[4];/* inode disk times */
/* for file compress */
- u64 i_compr_blocks; /* # of compressed blocks */
+ atomic64_t i_compr_blocks; /* # of compressed blocks */
unsigned char i_compress_algorithm; /* algorithm type */
unsigned char i_log_cluster_size; /* log of cluster size */
unsigned int i_cluster_size; /* cluster size */
@@ -3933,14 +3933,16 @@ static inline void set_compress_context(struct inode *inode)
static inline u64 f2fs_disable_compressed_file(struct inode *inode)
{
struct f2fs_inode_info *fi = F2FS_I(inode);
+ u64 i_compr_blocks;
if (!f2fs_compressed_file(inode))
return 0;
if (S_ISREG(inode->i_mode)) {
if (get_dirty_pages(inode))
return 1;
- if (fi->i_compr_blocks)
- return fi->i_compr_blocks;
Caller doesn't care how many compr_blocks this inode has saved, so we can just
return 1 here.
+ i_compr_blocks = atomic64_read(&fi->i_compr_blocks);
+ if (i_compr_blocks)
+ return i_compr_blocks;
}
fi->i_flags &= ~F2FS_COMPR_FL;
@@ -4057,16 +4059,17 @@ static inline void f2fs_i_compr_blocks_update(struct inode *inode,
u64 blocks, bool add)
{
int diff = F2FS_I(inode)->i_cluster_size - blocks;
+ struct f2fs_inode_info *fi = F2FS_I(inode);
/* don't update i_compr_blocks if saved blocks were released */
- if (!add && !F2FS_I(inode)->i_compr_blocks)
+ if (!add && !atomic64_read(&fi->i_compr_blocks))
return;
if (add) {
- F2FS_I(inode)->i_compr_blocks += diff;
+ atomic64_add(diff, &fi->i_compr_blocks);
stat_add_compr_blocks(inode, diff);
} else {
- F2FS_I(inode)->i_compr_blocks -= diff;
+ atomic64_sub(diff, &fi->i_compr_blocks);
stat_sub_compr_blocks(inode, diff);
}
f2fs_mark_inode_dirty_sync(inode, true);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index cc7f5670390f..4e4e369b97e5 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -564,7 +564,7 @@ void f2fs_truncate_data_blocks_range(struct dnode_of_data *dn, int count)
bool compressed_cluster = false;
int cluster_index = 0, valid_blocks = 0;
int cluster_size = F2FS_I(dn->inode)->i_cluster_size;
- bool released = !F2FS_I(dn->inode)->i_compr_blocks;
+ bool released = !atomic64_read(&F2FS_I(dn->inode)->i_compr_blocks);
if (IS_INODE(dn->node_page) && f2fs_has_extra_attr(dn->inode))
base = get_extra_isize(dn->inode);
@@ -3436,7 +3436,7 @@ static int f2fs_get_compress_blocks(struct file *filp, unsigned long arg)
if (!f2fs_compressed_file(inode))
return -EINVAL;
- blocks = F2FS_I(inode)->i_compr_blocks;
+ blocks = atomic64_read(&F2FS_I(inode)->i_compr_blocks);
return put_user(blocks, (u64 __user *)arg);
}
@@ -3535,7 +3535,7 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
if (ret)
goto out;
- if (!F2FS_I(inode)->i_compr_blocks)
+ if (!atomic64_read(&F2FS_I(inode)->i_compr_blocks))
goto out;
F2FS_I(inode)->i_flags |= F2FS_IMMUTABLE_FL;
@@ -3588,14 +3588,15 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
if (ret >= 0) {
ret = put_user(released_blocks, (u64 __user *)arg);
- } else if (released_blocks && F2FS_I(inode)->i_compr_blocks) {
+ } else if (released_blocks &&
+ atomic64_read(&F2FS_I(inode)->i_compr_blocks)) {
set_sbi_flag(sbi, SBI_NEED_FSCK);
f2fs_warn(sbi, "%s: partial blocks were released i_ino=%lx "
"iblocks=%llu, released=%u, compr_blocks=%llu, "
"run fsck to fix.",
__func__, inode->i_ino, inode->i_blocks,
released_blocks,
- F2FS_I(inode)->i_compr_blocks);
+ atomic64_read(&F2FS_I(inode)->i_compr_blocks));
}
return ret;
@@ -3683,7 +3684,7 @@ static int f2fs_reserve_compress_blocks(struct file *filp, unsigned long arg)
if (ret)
return ret;
- if (F2FS_I(inode)->i_compr_blocks)
+ if (atomic64_read(&F2FS_I(inode)->i_compr_blocks))
goto out;
f2fs_balance_fs(F2FS_I_SB(inode), true);
@@ -3747,14 +3748,15 @@ static int f2fs_reserve_compress_blocks(struct file *filp, unsigned long arg)
if (ret >= 0) {
ret = put_user(reserved_blocks, (u64 __user *)arg);
- } else if (reserved_blocks && F2FS_I(inode)->i_compr_blocks) {
+ } else if (reserved_blocks &&
+ atomic64_read(&F2FS_I(inode)->i_compr_blocks)) {
set_sbi_flag(sbi, SBI_NEED_FSCK);
f2fs_warn(sbi, "%s: partial blocks were released i_ino=%lx "
"iblocks=%llu, reserved=%u, compr_blocks=%llu, "
"run fsck to fix.",
__func__, inode->i_ino, inode->i_blocks,
reserved_blocks,
- F2FS_I(inode)->i_compr_blocks);
+ atomic64_read(&F2FS_I(inode)->i_compr_blocks));
}
return ret;
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 66969ae852b9..e86857af9699 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -442,7 +442,8 @@ static int do_read_inode(struct inode *inode)
(fi->i_flags & F2FS_COMPR_FL)) {
if (F2FS_FITS_IN_INODE(ri, fi->i_extra_isize,
i_log_cluster_size)) {
- fi->i_compr_blocks = le64_to_cpu(ri->i_compr_blocks);
+ atomic64_set(&fi->i_compr_blocks,
+ le64_to_cpu(ri->i_compr_blocks));
fi->i_compress_algorithm = ri->i_compress_algorithm;
fi->i_log_cluster_size = ri->i_log_cluster_size;
fi->i_cluster_size = 1 << fi->i_log_cluster_size;
@@ -460,7 +461,7 @@ static int do_read_inode(struct inode *inode)
stat_inc_inline_inode(inode);
stat_inc_inline_dir(inode);
stat_inc_compr_inode(inode);
- stat_add_compr_blocks(inode, F2FS_I(inode)->i_compr_blocks);
+ stat_add_compr_blocks(inode, atomic64_read(&fi->i_compr_blocks));
return 0;
}
@@ -619,7 +620,8 @@ void f2fs_update_inode(struct inode *inode, struct page *node_page)
F2FS_FITS_IN_INODE(ri, F2FS_I(inode)->i_extra_isize,
i_log_cluster_size)) {
ri->i_compr_blocks =
- cpu_to_le64(F2FS_I(inode)->i_compr_blocks);
+ cpu_to_le64(atomic64_read(
+ &F2FS_I(inode)->i_compr_blocks));
ri->i_compress_algorithm =
F2FS_I(inode)->i_compress_algorithm;
ri->i_log_cluster_size =
@@ -768,7 +770,8 @@ void f2fs_evict_inode(struct inode *inode)
stat_dec_inline_dir(inode);
stat_dec_inline_inode(inode);
stat_dec_compr_inode(inode);
- stat_sub_compr_blocks(inode, F2FS_I(inode)->i_compr_blocks);
+ stat_sub_compr_blocks(inode,
+ atomic64_read(&F2FS_I(inode)->i_compr_blocks));
if (likely(!f2fs_cp_error(sbi) &&
!is_sbi_flag_set(sbi, SBI_CP_DISABLED)))
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 83bf9a02f83f..65613500e1ab 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1011,6 +1011,7 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb)
/* Initialize f2fs-specific inode info */
atomic_set(&fi->dirty_pages, 0);
+ atomic64_set(&fi->i_compr_blocks, 0);
init_rwsem(&fi->i_sem);
spin_lock_init(&fi->i_size_lock);
INIT_LIST_HEAD(&fi->dirty_list);