FAILED: patch "[PATCH] block: Don't invalidate pagecache for invalid falloc modes" failed to apply to 5.4-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.4-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 <stable@vger.kernel.org>.

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-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 1364a3c391aedfeb32aa025303ead3d7c91cdf9d
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023101515-buffing-copy-1686@gregkh' --subject-prefix 'PATCH 5.4.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 <sarthakkukreti@chromium.org>
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.

Fixes: 25f4c41415e5 ("block: implement (some of) fallocate for block devices")
Cc: stable@vger.kernel.org
Reported-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Sarthak Kukreti <sarthakkukreti@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Fixes: line?  I've never seen those wrapped.
Link: https://lore.kernel.org/r/20231011201230.750105-1-sarthakkukreti@chromium.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/fops.c b/block/fops.c
index acff3d5d22d4..73e42742543f 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -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;