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@xxxxxxxxxx> > --- > 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@xxxxxxxxxxxxx > > 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 >
