[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <87zfiyqgkm.fsf@igalia.com>
Date: Fri, 07 Feb 2025 08:55:53 +0000
From: Luis Henriques <luis@...lia.com>
To: Miklos Szeredi <miklos@...redi.hu>
Cc: linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org, Matt
Harvey <mharvey@...ptrading.com>
Subject: Re: [RFC PATCH] fuse: add new function to invalidate cache for all
inodes
Hi Miklos,
On Wed, Jan 15 2025, Luis Henriques wrote:
> Currently userspace is able to notify the kernel to invalidate the cache
> for an inode. This means that, if all the inodes in a filesystem need to
> be invalidated, then userspace needs to iterate through all of them and do
> this kernel notification separately.
>
> This patch adds a new option that allows userspace to invalidate all the
> inodes with a single notification operation. In addition to invalidate all
> the inodes, it also shrinks the superblock dcache.
Gentle ping, any comments on how to improve/modify this patch so that it
could eventually be acceptable in mainline?
Cheers,
--
Luís
>
> Signed-off-by: Luis Henriques <luis@...lia.com>
> ---
> Just an additional note that this patch could eventually be simplified if
> Dave Chinner patch to iterate through the superblock inodes[1] is merged.
>
> [1] https://lore.kernel.org/r/20241002014017.3801899-3-david@fromorbit.com
>
> fs/fuse/inode.c | 53 +++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/fuse.h | 3 +++
> 2 files changed, 56 insertions(+)
>
> diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
> index 3ce4f4e81d09..1fd9a5f303da 100644
> --- a/fs/fuse/inode.c
> +++ b/fs/fuse/inode.c
> @@ -546,6 +546,56 @@ struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
> return NULL;
> }
>
> +static int fuse_reverse_inval_all(struct fuse_conn *fc)
> +{
> + struct fuse_mount *fm;
> + struct super_block *sb;
> + struct inode *inode, *old_inode = NULL;
> + struct fuse_inode *fi;
> +
> + inode = fuse_ilookup(fc, FUSE_ROOT_ID, NULL);
> + if (!inode)
> + return -ENOENT;
> +
> + fm = get_fuse_mount(inode);
> + iput(inode);
> + if (!fm)
> + return -ENOENT;
> + sb = fm->sb;
> +
> + spin_lock(&sb->s_inode_list_lock);
> + list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
> + spin_lock(&inode->i_lock);
> + if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
> + !atomic_read(&inode->i_count)) {
> + spin_unlock(&inode->i_lock);
> + continue;
> + }
> +
> + __iget(inode);
> + spin_unlock(&inode->i_lock);
> + spin_unlock(&sb->s_inode_list_lock);
> + iput(old_inode);
> +
> + fi = get_fuse_inode(inode);
> + spin_lock(&fi->lock);
> + fi->attr_version = atomic64_inc_return(&fm->fc->attr_version);
> + spin_unlock(&fi->lock);
> + fuse_invalidate_attr(inode);
> + forget_all_cached_acls(inode);
> +
> + old_inode = inode;
> + cond_resched();
> + spin_lock(&sb->s_inode_list_lock);
> + }
> + spin_unlock(&sb->s_inode_list_lock);
> + iput(old_inode);
> +
> + shrink_dcache_sb(sb);
> +
> + return 0;
> +}
> +
> int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
> loff_t offset, loff_t len)
> {
> @@ -554,6 +604,9 @@ int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
> pgoff_t pg_start;
> pgoff_t pg_end;
>
> + if (nodeid == FUSE_INVAL_ALL_INODES)
> + return fuse_reverse_inval_all(fc);
> +
> inode = fuse_ilookup(fc, nodeid, NULL);
> if (!inode)
> return -ENOENT;
> diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
> index f1e99458e29e..e9e78292d107 100644
> --- a/include/uapi/linux/fuse.h
> +++ b/include/uapi/linux/fuse.h
> @@ -658,6 +658,9 @@ enum fuse_notify_code {
> FUSE_NOTIFY_CODE_MAX,
> };
>
> +/* The nodeid to request to invalidate all inodes */
> +#define FUSE_INVAL_ALL_INODES 0
> +
> /* The read buffer is required to be at least 8k, but may be much larger */
> #define FUSE_MIN_READ_BUFFER 8192
>
Powered by blists - more mailing lists