On 2019/12/5 1:33, Greg KH wrote:
On Wed, Dec 04, 2019 at 09:11:37PM +0800, yu kuai wrote:
tmpfs support 'size', 'nr_blocks' and 'nr_inodes' mount options. mount or
remount them to zero means unlimited. 'size' and 'br_blocks' can remount
from limited to unlimited, while 'nr_inodes' can't.
The problem is fixed since upstream commit 0b5071dd323d ("
shmem_parse_options(): use a separate structure to keep the results"). But
in order to backport it, the amount of related patches need to backport is
huge.
So, I made some local changes to fix the problem.
Signed-off-by: yu kuai <yukuai3@xxxxxxxxxx>
---
mm/shmem.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index 3c8742655756..966fc69ee8fb 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -3444,7 +3444,7 @@ static int shmem_remount_fs(struct super_block *sb, int *flags, char *data)
inodes = sbinfo->max_inodes - sbinfo->free_inodes;
if (percpu_counter_compare(&sbinfo->used_blocks, config.max_blocks) > 0)
goto out;
- if (config.max_inodes < inodes)
+ if (config.max_inodes && config.max_inodes < inodes)
goto out;
/*
* Those tests disallow limited->unlimited while any are in use;
@@ -3460,7 +3460,10 @@ static int shmem_remount_fs(struct super_block *sb, int *flags, char *data)
sbinfo->huge = config.huge;
sbinfo->max_blocks = config.max_blocks;
sbinfo->max_inodes = config.max_inodes;
- sbinfo->free_inodes = config.max_inodes - inodes;
+ if (!config.max_inodes)
+ sbinfo->free_inodes = 0;
+ else
+ sbinfo->free_inodes = config.max_inodes - inodes;
/*
* Preserve previous mempolicy unless mpol remount option was specified.
--
2.17.2
Hm, sorry about my bot, this looked like an odd one-off patch.
What about 5.3.y, should this patch also go there as well?
Yes, 4.4y and 5.3y have the same problem.
But is it really an issue as this is a new "feature" that 5.4 now has,
can't you just use 5.4.y if you need this type of thing? It's never
worked in the past, right?
It's true that it never worked in the past. I thoult it might be a bug
because the behavior is not like what the document said.
Thanks for your response.
Yu Kuai
