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. 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
