From 0b116ff4dc40ec84ce4bfd451436e66ab2bbc86d Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 16 Apr 2024 04:17:51 +0100 Subject: [PATCH] buffer: improve bdev_getblk documentation Add some more information about the state of the buffer_head returned. Link: https://lkml.kernel.org/r/20240416031754.4076917-8-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Cc: Pankaj Raghav Signed-off-by: Andrew Morton --- fs/buffer.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/buffer.c b/fs/buffer.c index 60829312787a..ed698caa8834 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1424,6 +1424,11 @@ EXPORT_SYMBOL(__find_get_block); * @size: The size of buffer_heads for this @bdev. * @gfp: The memory allocation flags to use. * + * The returned buffer head has its reference count incremented, but is + * not locked. The caller should call brelse() when it has finished + * with the buffer. The buffer may not be uptodate. If needed, the + * caller can bring it uptodate either by reading it or overwriting it. + * * Return: The buffer head, or NULL if memory could not be allocated. */ struct buffer_head *bdev_getblk(struct block_device *bdev, sector_t block,