From e44be00289ef3ce8195d915cf354714b14fd30a4 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 23 Jul 2024 18:14:54 -0700 Subject: hostfs: fix folio conversion MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit e3ec0fe944d2 ("hostfs: Convert hostfs_read_folio() to use a folio") simplified hostfs_read_folio(), but in the process of converting to using folios natively also mis-used the folio_zero_tail() function due to the very confusing API of that function. Very arguably it's folio_zero_tail() API itself that is buggy, since it would make more sense (and the documentation kind of implies) that the third argument would be the pointer to the beginning of the folio buffer. But no, the third argument to folio_zero_tail() is where we should start zeroing the tail (even if we already also pass in the offset separately as the second argument). So fix the hostfs caller, and we can leave any folio_zero_tail() sanity cleanup for later. Reported-and-tested-by: Maciej Żenczykowski Fixes: e3ec0fe944d2 ("hostfs: Convert hostfs_read_folio() to use a folio") Link: https://lore.kernel.org/all/CANP3RGceNzwdb7w=vPf5=7BCid5HVQDmz1K5kC9JG42+HVAh_g@mail.gmail.com/ Cc: Matthew Wilcox Cc: Christian Brauner Signed-off-by: Linus Torvalds --- fs/hostfs/hostfs_kern.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c index 3eb747d26924..2b532670a561 100644 --- a/fs/hostfs/hostfs_kern.c +++ b/fs/hostfs/hostfs_kern.c @@ -455,7 +455,7 @@ static int hostfs_read_folio(struct file *file, struct folio *folio) if (bytes_read < 0) ret = bytes_read; else - buffer = folio_zero_tail(folio, bytes_read, buffer); + buffer = folio_zero_tail(folio, bytes_read, buffer + bytes_read); kunmap_local(buffer); folio_end_read(folio, ret == 0); -- cgit v1.2.3