FAILED: patch "[PATCH] block: Don't invalidate pagecache for invalid falloc modes" failed to apply to 4.19-stable tree

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x 1364a3c391aedfeb32aa025303ead3d7c91cdf9d
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023101516-genetics-gratify-225c@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:

1364a3c391ae ("block: Don't invalidate pagecache for invalid falloc modes") 05bdb9965305 ("block: replace fmode_t with a block-specific type for block open flags") 5e4ea834676e ("block: remove unused fmode_t arguments from ioctl handlers") cfb425761c79 ("block: move a few internal definitions out of blkdev.h") 99b07780814e ("rnbd-srv: replace sess->open_flags with a "bool readonly"") 658afed19cee ("mtd: block: use a simple bool to track open for write") 7d9d7d59d44b ("nvme: replace the fmode_t argument to the nvme ioctl handlers with a simple bool") 2e80089c1824 ("scsi: replace the fmode_t argument to scsi_ioctl with a simple bool") 5f4eb9d5413f ("scsi: replace the fmode_t argument to scsi_cmd_allowed with a simple bool") 81b1fb7d17c0 ("fs: remove sb->s_mode")
3f0b3e785e8b ("block: add a sb_open_mode helper")
2736e8eeb0cc ("block: use the holder as indication for exclusive opens") 2ef789288afd ("btrfs: don't pass a holder for non-exclusive blkdev_get_by_path") 29499ab060fe ("bcache: don't pass a stack address to blkdev_get_by_path") c889d0793d9d ("swsusp: don't pass a stack address to blkdev_get_by_path") ae220766d87c ("block: remove the unused mode argument to ->release")
d32e2bf83791 ("block: pass a gendisk to ->open")
444aa2c58cb3 ("block: pass a gendisk on bdev_check_media_change")
7ae24fcee992 ("cdrom: remove the unused mode argument to cdrom_release") 473399b50de1 ("cdrom: remove the unused mode argument to cdrom_ioctl")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 1364a3c391aedfeb32aa025303ead3d7c91cdf9d Mon Sep 17 00:00:00 2001
From: Sarthak Kukreti <[email protected]>
Date: Wed, 11 Oct 2023 13:12:30 -0700
Subject: [PATCH] block: Don't invalidate pagecache for invalid falloc modes

Only call truncate_bdev_range() if the fallocate mode is supported. This fixes a bug where data in the pagecache could be invalidated if the fallocate() was called on the block device with an invalid mode.

index acff3d5d22d4..73e42742543f 100644
@@ -772,24 +772,35 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start,
 
 	filemap_invalidate_lock(inode->i_mapping);
 
-	/* Invalidate the page cache, including dirty pages. */
-	error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end);
-	if (error)
-		goto fail;
-
+	/*
+	 * Invalidate the page cache, including dirty pages, for valid
+	 * de-allocate mode calls to fallocate().
+	 */
 	switch (mode) {
 	case FALLOC_FL_ZERO_RANGE:
 	case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE:
+		error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end);
+		if (error)
+			goto fail;
+
 		error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT,
 					     len >> SECTOR_SHIFT, GFP_KERNEL,
 					     BLKDEV_ZERO_NOUNMAP);
 		break;
 	case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
+		error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end);
+		if (error)
+			goto fail;
+
 		error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT,
 					     len >> SECTOR_SHIFT, GFP_KERNEL,
 					     BLKDEV_ZERO_NOFALLBACK);
 		break;
 	case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE:
+		error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end);
+		if (error)
+			goto fail;
+
 		error = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT,
 					     len >> SECTOR_SHIFT, GFP_KERNEL);
 		break;

Only call truncate_bdev_range() if the fallocate mode is supported. This fixes a bug where data in the pagecache could be invalidated if the fallocate() was called on the block device with an invalid mode.

---
 fs/block_dev.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

index b34f76af59c4..5c6ff1572405 100644
@@ -2041,21 +2041,26 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start,
 	if ((start | len) & (bdev_logical_block_size(bdev) - 1))
 		return -EINVAL;
 
-	/* Invalidate the page cache, including dirty pages. */
+	/*
+	 * Invalidate the page cache, including dirty pages, for valid
+	 * de-allocate mode calls to fallocate().
+	 */
 	mapping = bdev->bd_inode->i_mapping;
-	truncate_inode_pages_range(mapping, start, end);
 
 	switch (mode) {
 	case FALLOC_FL_ZERO_RANGE:
 	case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE:
+		truncate_inode_pages_range(mapping, start, end);
 		error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
 					    GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
 		break;
 	case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
+		truncate_inode_pages_range(mapping, start, end);
 		error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
 					     GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK);
 		break;
 	case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE:
+		truncate_inode_pages_range(mapping, start, end);
 		error = blkdev_issue_discard(bdev, start >> 9, len >> 9,
 					     GFP_KERNEL, 0);
 		break;

2.43.0.472.g3155946c3a-goog