Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 435a502..1279359 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1163,7 +1163,7 @@
 	int del_nr = 0;
 	int del_slot = 0;
 	int recow;
-	int ret;
+	int ret = 0;
 	u64 ino = btrfs_ino(inode);
 
 	path = btrfs_alloc_path();
@@ -1384,7 +1384,7 @@
 	}
 out:
 	btrfs_free_path(path);
-	return 0;
+	return ret;
 }
 
 /*
@@ -1546,8 +1546,8 @@
 	return ret;
 }
 
-static noinline int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
-				    size_t *write_bytes)
+int btrfs_check_can_nocow(struct btrfs_inode *inode, loff_t pos,
+			  size_t *write_bytes)
 {
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 	struct btrfs_root *root = inode->root;
@@ -1568,7 +1568,7 @@
 
 	num_bytes = lockend - lockstart + 1;
 	ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
-			NULL, NULL, NULL);
+			NULL, NULL, NULL, false);
 	if (ret <= 0) {
 		ret = 0;
 		btrfs_end_write_no_snapshotting(root);
@@ -1636,6 +1636,7 @@
 			break;
 		}
 
+		only_release_metadata = false;
 		sector_offset = pos & (fs_info->sectorsize - 1);
 		reserve_bytes = round_up(write_bytes + sector_offset,
 				fs_info->sectorsize);
@@ -1646,7 +1647,7 @@
 		if (ret < 0) {
 			if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
 						      BTRFS_INODE_PREALLOC)) &&
-			    check_can_nocow(BTRFS_I(inode), pos,
+			    btrfs_check_can_nocow(BTRFS_I(inode), pos,
 					&write_bytes) > 0) {
 				/*
 				 * For nodata cow case, no need to reserve
@@ -1791,7 +1792,6 @@
 			set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
 				       lockend, EXTENT_NORESERVE, NULL,
 				       NULL, GFP_NOFS);
-			only_release_metadata = false;
 		}
 
 		btrfs_drop_pages(pages, num_pages);
@@ -1903,9 +1903,10 @@
 	    (iocb->ki_flags & IOCB_NOWAIT))
 		return -EOPNOTSUPP;
 
-	if (!inode_trylock(inode)) {
-		if (iocb->ki_flags & IOCB_NOWAIT)
+	if (iocb->ki_flags & IOCB_NOWAIT) {
+		if (!inode_trylock(inode))
 			return -EAGAIN;
+	} else {
 		inode_lock(inode);
 	}
 
@@ -1918,13 +1919,28 @@
 	pos = iocb->ki_pos;
 	count = iov_iter_count(from);
 	if (iocb->ki_flags & IOCB_NOWAIT) {
+		size_t nocow_bytes = count;
+
 		/*
 		 * We will allocate space in case nodatacow is not set,
 		 * so bail
 		 */
 		if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
 					      BTRFS_INODE_PREALLOC)) ||
-		    check_can_nocow(BTRFS_I(inode), pos, &count) <= 0) {
+		    btrfs_check_can_nocow(BTRFS_I(inode), pos,
+					  &nocow_bytes) <= 0) {
+			inode_unlock(inode);
+			return -EAGAIN;
+		}
+
+		/* check_can_nocow() locks the snapshot lock on success */
+		btrfs_end_write_no_snapshotting(root);
+		/*
+		 * There are holes in the range or parts of the range that must
+		 * be COWed (shared extents, RO block groups, etc), so just bail
+		 * out.
+		 */
+		if (nocow_bytes < count) {
 			inode_unlock(inode);
 			return -EAGAIN;
 		}
@@ -1988,14 +2004,8 @@
 
 	inode_unlock(inode);
 
-	/*
-	 * We also have to set last_sub_trans to the current log transid,
-	 * otherwise subsequent syncs to a file that's been synced in this
-	 * transaction will appear to have already occurred.
-	 */
-	spin_lock(&BTRFS_I(inode)->lock);
-	BTRFS_I(inode)->last_sub_trans = root->log_transid;
-	spin_unlock(&BTRFS_I(inode)->lock);
+	btrfs_set_inode_last_sub_trans(BTRFS_I(inode));
+
 	if (num_written > 0)
 		num_written = generic_write_sync(iocb, num_written);
 
@@ -2073,6 +2083,16 @@
 	btrfs_init_log_ctx(&ctx, inode);
 
 	/*
+	 * Set the range to full if the NO_HOLES feature is not enabled.
+	 * This is to avoid missing file extent items representing holes after
+	 * replaying the log.
+	 */
+	if (!btrfs_fs_incompat(fs_info, NO_HOLES)) {
+		start = 0;
+		end = LLONG_MAX;
+	}
+
+	/*
 	 * We write the dirty pages in the range and wait until they complete
 	 * out of the ->i_mutex. If so, we can flush the dirty pages by
 	 * multi-task, and make the performance up.  See
@@ -2126,6 +2146,7 @@
 	 */
 	ret = start_ordered_ops(inode, start, end);
 	if (ret) {
+		up_write(&BTRFS_I(inode)->dio_sem);
 		inode_unlock(inode);
 		goto out;
 	}
@@ -2601,8 +2622,8 @@
 			}
 		}
 
-		if (clone_info) {
-			u64 clone_len = drop_end - cur_offset;
+		if (clone_info && drop_end > clone_info->file_offset) {
+			u64 clone_len = drop_end - clone_info->file_offset;
 
 			ret = btrfs_insert_clone_extent(trans, inode, path,
 							clone_info, clone_len);
@@ -3118,14 +3139,17 @@
 		if (ret < 0)
 			goto out;
 		space_reserved = true;
-		ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
-						alloc_start, bytes_to_reserve);
-		if (ret)
-			goto out;
 		ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
 						  &cached_state);
 		if (ret)
 			goto out;
+		ret = btrfs_qgroup_reserve_data(BTRFS_I(inode), &data_reserved,
+						alloc_start, bytes_to_reserve);
+		if (ret) {
+			unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
+					     lockend, &cached_state);
+			goto out;
+		}
 		ret = btrfs_prealloc_file_range(inode, mode, alloc_start,
 						alloc_end - alloc_start,
 						i_blocksize(inode),
@@ -3292,8 +3316,9 @@
 				free_extent_map(em);
 				break;
 			}
-			ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
-					cur_offset, last_byte - cur_offset);
+			ret = btrfs_qgroup_reserve_data(BTRFS_I(inode),
+					&data_reserved, cur_offset,
+					last_byte - cur_offset);
 			if (ret < 0) {
 				cur_offset = last_byte;
 				free_extent_map(em);