[PATCH 10/13] f2fs: Convert to using invalidate_lock

Jan Kara
2021-05-25T13:51:22Z

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
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/f2fs/data.c | 4 ++--
fs/f2fs/f2fs.h | 1 -
fs/f2fs/file.c | 62 ++++++++++++++++++++++++-------------------------
fs/f2fs/super.c | 1 -
4 files changed, 32 insertions(+), 36 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 96f1a354f89f..f3177d03c28f 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3165,12 +3165,12 @@ 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);
+ down_write(&mapping->invalidate_lock);

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

- up_write(&F2FS_I(inode)->i_mmap_sem);
+ up_write(&mapping->invalidate_lock);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
}
}
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 044878866ca3..1f887c906aaf 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -748,7 +748,6 @@ 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 44a4650aea7b..3899ce46b67a 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);
@@ -102,7 +99,7 @@ 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);
+ down_read(&inode->i_mapping->invalidate_lock);
lock_page(page);
if (unlikely(page->mapping != inode->i_mapping ||
page_offset(page) > i_size_read(inode) ||
@@ -161,7 +158,7 @@ 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);
+ up_read(&inode->i_mapping->invalidate_lock);

sb_end_pagefault(inode->i_sb);
err:
@@ -942,7 +939,7 @@ 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);
+ down_write(&inode->i_mapping->invalidate_lock);

truncate_setsize(inode, attr->ia_size);

@@ -952,7 +949,7 @@ 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);
+ up_write(&inode->i_mapping->invalidate_lock);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
if (err)
return err;
@@ -1097,7 +1094,7 @@ 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);
+ down_write(&mapping->invalidate_lock);

truncate_inode_pages_range(mapping, blk_start,
blk_end - 1);
@@ -1106,7 +1103,7 @@ 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);
+ up_write(&mapping->invalidate_lock);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
}
}
@@ -1341,7 +1338,7 @@ 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);
+ down_write(&inode->i_mapping->invalidate_lock);

f2fs_lock_op(sbi);
f2fs_drop_extent_tree(inode);
@@ -1349,7 +1346,7 @@ 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);
+ up_write(&inode->i_mapping->invalidate_lock);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
return ret;
}
@@ -1380,13 +1377,13 @@ 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);
+ down_write(&inode->i_mapping->invalidate_lock);
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);
+ up_write(&inode->i_mapping->invalidate_lock);
if (!ret)
f2fs_i_size_write(inode, new_size);
return ret;
@@ -1486,7 +1483,7 @@ 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);
+ down_write(&mapping->invalidate_lock);

truncate_pagecache_range(inode,
(loff_t)index << PAGE_SHIFT,
@@ -1498,7 +1495,7 @@ 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);
+ up_write(&mapping->invalidate_lock);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
goto out;
}
@@ -1510,7 +1507,7 @@ 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);
+ up_write(&mapping->invalidate_lock);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);

f2fs_balance_fs(sbi, dn.node_changed);
@@ -1545,6 +1542,7 @@ 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;
@@ -1567,14 +1565,14 @@ 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);
+ down_write(&mapping->invalidate_lock);
ret = f2fs_truncate_blocks(inode, i_size_read(inode), true);
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ up_write(&mapping->invalidate_lock);
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;

@@ -1585,7 +1583,7 @@ 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);
+ down_write(&mapping->invalidate_lock);
truncate_pagecache(inode, offset);

while (!ret && idx > pg_start) {
@@ -1601,14 +1599,14 @@ 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);
+ up_write(&mapping->invalidate_lock);
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);
+ down_write(&mapping->invalidate_lock);
+ filemap_write_and_wait_range(mapping, offset, LLONG_MAX);
truncate_pagecache(inode, offset);
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ up_write(&mapping->invalidate_lock);

if (!ret)
f2fs_i_size_write(inode, new_size);
@@ -3442,7 +3440,7 @@ 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);
+ down_write(&inode->i_mapping->invalidate_lock);

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

@@ -3478,7 +3476,7 @@ 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);
+ up_write(&inode->i_mapping->invalidate_lock);
out:
inode_unlock(inode);

@@ -3595,7 +3593,7 @@ 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);
+ down_write(&inode->i_mapping->invalidate_lock);

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

@@ -3631,7 +3629,7 @@ 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);
+ up_write(&inode->i_mapping->invalidate_lock);

if (ret >= 0) {
F2FS_I(inode)->i_flags &= ~F2FS_IMMUTABLE_FL;
@@ -3751,7 +3749,7 @@ 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);
+ down_write(&mapping->invalidate_lock);

ret = filemap_write_and_wait_range(mapping, range.start,
to_end ? LLONG_MAX : end_addr - 1);
@@ -3838,7 +3836,7 @@ 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);
+ up_write(&mapping->invalidate_lock);
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);
+ down_write(&inode->i_mapping->invalidate_lock);
f2fs_truncate(inode);
- up_write(&F2FS_I(inode)->i_mmap_sem);
+ up_write(&inode->i_mapping->invalidate_lock);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
}

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 7d325bfaf65a..22e942aac7ad 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1187,7 +1187,6 @@ 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