+ mm-fadvise-use-llong_max-instead-of-1-for-eof.patch added to mm-unstable branch

+ mm-fadvise-use-llong_max-instead-of-1-for-eof.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/fadvise: use LLONG_MAX instead of -1 for eof
has been added to the -mm mm-unstable branch.  Its filename is
     mm-fadvise-use-llong_max-instead-of-1-for-eof.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-fadvise-use-llong_max-instead-of-1-for-eof.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Brian Foster <bfoster@redhat.com>
Subject: mm/fadvise: use LLONG_MAX instead of -1 for eof
Date: Mon, 28 Nov 2022 10:56:32 -0500

generic_fadvise() sets endbyte = -1 to specify end of file (i.e.  if
length == 0 is passed from userspace).  Most other callers to
filemap_fdatawrite_range() use LLONG_MAX for this purpose, particularly if
they also call fdatawait_range() (which requires end >= start).  For
example, sync_file_range(), vfs_fsync() (where the range is passed down
through per-fs ->fsync() callbacks), filemap_flush(), etc. 
generic_fadvise() does not currently wait on writeback, but fix the call
up to be consistent with other callers.

Link: https://lkml.kernel.org/r/20221128155632.3950447-3-bfoster@redhat.com
Signed-off-by: Brian Foster <bfoster@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/fadvise.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/fadvise.c~mm-fadvise-use-llong_max-instead-of-1-for-eof
+++ a/mm/fadvise.c
@@ -72,7 +72,7 @@ int generic_fadvise(struct file *file, l
 	 */
 	endbyte = (u64)offset + (u64)len;
 	if (!len || endbyte < len)
-		endbyte = -1;
+		endbyte = LLONG_MAX;
 	else
 		endbyte--;		/* inclusive */
 
_

Patches currently in -mm which might be from bfoster@redhat.com are

filemap-skip-write-and-wait-if-end-offset-precedes-start.patch
mm-fadvise-use-llong_max-instead-of-1-for-eof.patch