[PATCH 11/14] f2fs: Convert to using invalidate_lock

Jan Kara
2021-07-12T16:56:35Z

Use invalidate_lock instead of f2fs' private i_mmap_sem. The intended
purpose is exactly the same. By this conversion we fix a long standing
race between hole punching and read(2) / readahead(2) paths that can
lead to stale page cache contents.

CC: Jaegeuk Kim <jaegeuk@kernel.org>
CC: Chao Yu <yuchao0@huawei.com>
CC: linux-f2fs-devel@lists.sourceforge.net
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/f2fs/data.c | 8 +++----
fs/f2fs/f2fs.h | 1 -
fs/f2fs/file.c | 62 ++++++++++++++++++++++++-------------------------
fs/f2fs/super.c | 1 -
4 files changed, 34 insertions(+), 38 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index d2cf48c5a2e4..eb222b35edef 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3187,12 +3187,12 @@ static void f2fs_write_failed(struct address_space *mapping, loff_t to)
/* In the fs-verity case, f2fs_end_enable_verity() does the truncate */
if (to > i_size && !f2fs_verity_in_progress(inode)) {
down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
- down_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock(mapping);

truncate_pagecache(inode, i_size);
f2fs_truncate_blocks(inode, i_size, true);

- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(mapping);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
}
}
@@ -3852,7 +3852,7 @@ static int f2fs_migrate_blocks(struct inode *inode, block_t start_blk,
int ret = 0;

down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
- down_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock(inode->i_mapping);

set_inode_flag(inode, FI_ALIGNED_WRITE);

@@ -3894,7 +3894,7 @@ static int f2fs_migrate_blocks(struct inode *inode, block_t start_blk,
clear_inode_flag(inode, FI_DO_DEFRAG);
clear_inode_flag(inode, FI_ALIGNED_WRITE);

- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(inode->i_mapping);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);

return ret;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index ee8eb33e2c25..906b2c4b50e7 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -754,7 +754,6 @@ struct f2fs_inode_info {

/* avoid racing between foreground op and gc */
struct rw_semaphore i_gc_rwsem[2];
- struct rw_semaphore i_mmap_sem;
struct rw_semaphore i_xattr_sem; /* avoid racing between reading and changing EAs */

int i_extra_isize; /* size of extra space located in i_addr */
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 6afd4562335f..1ff333755721 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -38,10 +38,7 @@ static vm_fault_t f2fs_filemap_fault(struct vm_fault *vmf)
struct inode *inode = file_inode(vmf->vma->vm_file);
vm_fault_t ret;

- down_read(&F2FS_I(inode)->i_mmap_sem);
ret = filemap_fault(vmf);
- up_read(&F2FS_I(inode)->i_mmap_sem);
-
if (!ret)
f2fs_update_iostat(F2FS_I_SB(inode), APP_MAPPED_READ_IO,
F2FS_BLKSIZE);
@@ -101,7 +98,7 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
f2fs_bug_on(sbi, f2fs_has_inline_data(inode));

file_update_time(vmf->vma->vm_file);
- down_read(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock_shared(inode->i_mapping);
lock_page(page);
if (unlikely(page->mapping != inode->i_mapping ||
page_offset(page) > i_size_read(inode) ||
@@ -159,7 +156,7 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)

trace_f2fs_vm_page_mkwrite(page, DATA);
out_sem:
- up_read(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock_shared(inode->i_mapping);

sb_end_pagefault(inode->i_sb);
err:
@@ -940,7 +937,7 @@ int f2fs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
}

down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
- down_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock(inode->i_mapping);

truncate_setsize(inode, attr->ia_size);

@@ -950,7 +947,7 @@ int f2fs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
* do not trim all blocks after i_size if target size is
* larger than i_size.
*/
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(inode->i_mapping);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
if (err)
return err;
@@ -1095,7 +1092,7 @@ static int punch_hole(struct inode *inode, loff_t offset, loff_t len)
blk_end = (loff_t)pg_end << PAGE_SHIFT;

down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
- down_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock(mapping);

truncate_inode_pages_range(mapping, blk_start,
blk_end - 1);
@@ -1104,7 +1101,7 @@ static int punch_hole(struct inode *inode, loff_t offset, loff_t len)
ret = f2fs_truncate_hole(inode, pg_start, pg_end);
f2fs_unlock_op(sbi);

- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(mapping);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
}
}
@@ -1339,7 +1336,7 @@ static int f2fs_do_collapse(struct inode *inode, loff_t offset, loff_t len)

/* avoid gc operation during block exchange */
down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
- down_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock(inode->i_mapping);

f2fs_lock_op(sbi);
f2fs_drop_extent_tree(inode);
@@ -1347,7 +1344,7 @@ static int f2fs_do_collapse(struct inode *inode, loff_t offset, loff_t len)
ret = __exchange_data_block(inode, inode, end, start, nrpages - end, true);
f2fs_unlock_op(sbi);

- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(inode->i_mapping);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
return ret;
}
@@ -1378,13 +1375,13 @@ static int f2fs_collapse_range(struct inode *inode, loff_t offset, loff_t len)
return ret;

/* write out all moved pages, if possible */
- down_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock(inode->i_mapping);
filemap_write_and_wait_range(inode->i_mapping, offset, LLONG_MAX);
truncate_pagecache(inode, offset);

new_size = i_size_read(inode) - len;
ret = f2fs_truncate_blocks(inode, new_size, true);
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(inode->i_mapping);
if (!ret)
f2fs_i_size_write(inode, new_size);
return ret;
@@ -1484,7 +1481,7 @@ static int f2fs_zero_range(struct inode *inode, loff_t offset, loff_t len,
pgoff_t end;

down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
- down_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock(mapping);

truncate_pagecache_range(inode,
(loff_t)index << PAGE_SHIFT,
@@ -1496,7 +1493,7 @@ static int f2fs_zero_range(struct inode *inode, loff_t offset, loff_t len,
ret = f2fs_get_dnode_of_data(&dn, index, ALLOC_NODE);
if (ret) {
f2fs_unlock_op(sbi);
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(mapping);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
goto out;
}
@@ -1508,7 +1505,7 @@ static int f2fs_zero_range(struct inode *inode, loff_t offset, loff_t len,
f2fs_put_dnode(&dn);

f2fs_unlock_op(sbi);
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(mapping);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);

f2fs_balance_fs(sbi, dn.node_changed);
@@ -1543,6 +1540,7 @@ static int f2fs_zero_range(struct inode *inode, loff_t offset, loff_t len,
static int f2fs_insert_range(struct inode *inode, loff_t offset, loff_t len)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ struct address_space *mapping = inode->i_mapping;
pgoff_t nr, pg_start, pg_end, delta, idx;
loff_t new_size;
int ret = 0;
@@ -1565,14 +1563,14 @@ static int f2fs_insert_range(struct inode *inode, loff_t offset, loff_t len)

f2fs_balance_fs(sbi, true);

- down_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock(mapping);
ret = f2fs_truncate_blocks(inode, i_size_read(inode), true);
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(mapping);
if (ret)
return ret;

/* write out all dirty pages from offset */
- ret = filemap_write_and_wait_range(inode->i_mapping, offset, LLONG_MAX);
+ ret = filemap_write_and_wait_range(mapping, offset, LLONG_MAX);
if (ret)
return ret;

@@ -1583,7 +1581,7 @@ static int f2fs_insert_range(struct inode *inode, loff_t offset, loff_t len)

/* avoid gc operation during block exchange */
down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
- down_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock(mapping);
truncate_pagecache(inode, offset);

while (!ret && idx > pg_start) {
@@ -1599,14 +1597,14 @@ static int f2fs_insert_range(struct inode *inode, loff_t offset, loff_t len)
idx + delta, nr, false);
f2fs_unlock_op(sbi);
}
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(mapping);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);

/* write out all moved pages, if possible */
- down_write(&F2FS_I(inode)->i_mmap_sem);
- filemap_write_and_wait_range(inode->i_mapping, offset, LLONG_MAX);
+ filemap_invalidate_lock(mapping);
+ filemap_write_and_wait_range(mapping, offset, LLONG_MAX);
truncate_pagecache(inode, offset);
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(mapping);

if (!ret)
f2fs_i_size_write(inode, new_size);
@@ -3440,7 +3438,7 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
goto out;

down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
- down_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock(inode->i_mapping);

last_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);

@@ -3476,7 +3474,7 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
}

up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(inode->i_mapping);
out:
inode_unlock(inode);

@@ -3593,7 +3591,7 @@ static int f2fs_reserve_compress_blocks(struct file *filp, unsigned long arg)
}

down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
- down_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock(inode->i_mapping);

last_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);

@@ -3629,7 +3627,7 @@ static int f2fs_reserve_compress_blocks(struct file *filp, unsigned long arg)
}

up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(inode->i_mapping);

if (ret >= 0) {
clear_inode_flag(inode, FI_COMPRESS_RELEASED);
@@ -3748,7 +3746,7 @@ static int f2fs_sec_trim_file(struct file *filp, unsigned long arg)
goto err;

down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
- down_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock(mapping);

ret = filemap_write_and_wait_range(mapping, range.start,
to_end ? LLONG_MAX : end_addr - 1);
@@ -3835,7 +3833,7 @@ static int f2fs_sec_trim_file(struct file *filp, unsigned long arg)
ret = f2fs_secure_erase(prev_bdev, inode, prev_index,
prev_block, len, range.flags);
out:
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(mapping);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
err:
inode_unlock(inode);
@@ -4313,9 +4311,9 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
/* if we couldn't write data, we should deallocate blocks. */
if (preallocated && i_size_read(inode) < target_size) {
down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
- down_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock(inode->i_mapping);
f2fs_truncate(inode);
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock(inode->i_mapping);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
}

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 8fecd3050ccd..ce2ab1b85c11 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1289,7 +1289,6 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb)
mutex_init(&fi->inmem_lock);
init_rwsem(&fi->i_gc_rwsem[READ]);
init_rwsem(&fi->i_gc_rwsem[WRITE]);
- init_rwsem(&fi->i_mmap_sem);
init_rwsem(&fi->i_xattr_sem);

/* Will be used by directory only */
--
2.26.2