[PATCH 09/20] f2fs: support subpage blocks in pinned files

[Daeho Jeong <daeho43@gmail.com>]

From: Daeho Jeong <daehojeong@google.com>

Pinned files must not allocate blocks outside fallocate(). As write()
does, return -EIO from page_mkwrite when the folio range up to EOF is
not fully allocated, and remove the -EOPNOTSUPP checks.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
---
 fs/f2fs/file.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index e68553cef777..36da0d558ef0 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -240,6 +240,13 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
 	nr = DIV_ROUND_UP(dirty_len, PAGE_SIZE);
 
 	if (f2fs_has_subpage_blocks(sbi)) {
+		if (f2fs_is_pinned_file(inode) &&
+		    !f2fs_overwrite_io(inode, folio_pos(folio), dirty_len)) {
+			folio_unlock(folio);
+			err = -EIO;
+			goto out_sem;
+		}
+
 		/*
 		 * A writable PTE covers the whole base folio.  Like ext4's
 		 * block_page_mkwrite(), prepare every filesystem block through EOF
@@ -2280,8 +2287,7 @@ static long f2fs_fallocate(struct file *file, int mode,
 
 	if (f2fs_has_subpage_blocks(F2FS_I_SB(inode))) {
 		if ((mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE)) ||
-		    f2fs_is_pinned_file(inode) || f2fs_is_atomic_file(inode) ||
-		    f2fs_compressed_file(inode)) {
+		    f2fs_is_atomic_file(inode) || f2fs_compressed_file(inode)) {
 			ret = -EOPNOTSUPP;
 			goto out;
 		}
@@ -3823,9 +3829,6 @@ static int f2fs_ioc_set_pin_file(struct file *filp, unsigned long arg)
 	__u32 pin;
 	int ret = 0;
 
-	if (f2fs_has_subpage_blocks(sbi))
-		return -EOPNOTSUPP;
-
 	if (get_user(pin, (__u32 __user *)arg))
 		return -EFAULT;
 
-- 
2.56.0.317.g454f8302e1-goog