diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 025ca032043dca..6c684c873e5363 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -2043,6 +2043,42 @@ static int fuse_notify_inc_epoch(struct fuse_conn *fc) return 0; } +static int fuse_notify_prune(struct fuse_conn *fc, unsigned int size, + struct fuse_copy_state *cs) +{ + struct fuse_notify_prune_out outarg; + const unsigned int batch = 512; + u64 *nodeids __free(kfree) = kmalloc(sizeof(u64) * batch, GFP_KERNEL); + unsigned int num, i; + int err; + + if (!nodeids) + return -ENOMEM; + + if (size < sizeof(outarg)) + return -EINVAL; + + err = fuse_copy_one(cs, &outarg, sizeof(outarg)); + if (err) + return err; + + if (size - sizeof(outarg) != outarg.count * sizeof(u64)) + return -EINVAL; + + for (; outarg.count; outarg.count -= num) { + num = min(batch, outarg.count); + err = fuse_copy_one(cs, nodeids, num * sizeof(u64)); + if (err) + return err; + + scoped_guard(rwsem_read, &fc->killsb) { + for (i = 0; i < num; i++) + fuse_try_prune_one_inode(fc, nodeids[i]); + } + } + return 0; +} + static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code, unsigned int size, struct fuse_copy_state *cs) { @@ -2074,6 +2110,9 @@ static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code, case FUSE_NOTIFY_INC_EPOCH: return fuse_notify_inc_epoch(fc); + case FUSE_NOTIFY_PRUNE: + return fuse_notify_prune(fc, size, cs); + default: fuse_copy_finish(cs); return -EINVAL; diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 0db4005acd2c90..ae9b7cd2be0b98 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -1471,6 +1471,12 @@ int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid, int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid, u64 child_nodeid, struct qstr *name, u32 flags); +/* + * Try to prune this inode. If neither the inode itself nor dentries associated + * with this inode have any external reference, then the inode can be freed. + */ +void fuse_try_prune_one_inode(struct fuse_conn *fc, u64 nodeid); + int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file, bool isdir); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 1e312ba6da30c8..978b3f8bb7e545 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -659,6 +659,27 @@ int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid, return 0; } +void fuse_try_prune_one_inode(struct fuse_conn *fc, u64 nodeid) +{ + struct inode *inode; + struct dentry *dentry; + + inode = fuse_ilookup(fc, nodeid, NULL); + if (!inode) + return; + + if (S_ISDIR(inode->i_mode)) { + dentry = d_find_alias(inode); + if (dentry) { + shrink_dcache_parent(dentry); + dput(dentry); + } + } + + d_prune_aliases(inode); + iput(inode); +} + bool fuse_lock_inode(struct inode *inode) { bool locked = false; diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index 3cb85385cb87f5..7b8dd1f36f090c 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -235,6 +235,7 @@ * * 7.44 * - add FUSE_NOTIFY_INC_EPOCH + * - add FUSE_NOTIFY_PRUNE */ #ifndef _LINUX_FUSE_H @@ -696,7 +697,7 @@ enum fuse_notify_code { FUSE_NOTIFY_DELETE = 6, FUSE_NOTIFY_RESEND = 7, FUSE_NOTIFY_INC_EPOCH = 8, - FUSE_NOTIFY_CODE_MAX, + FUSE_NOTIFY_PRUNE = 9, }; /* The read buffer is required to be at least 8k, but may be much larger */ @@ -1140,6 +1141,12 @@ struct fuse_notify_retrieve_in { uint64_t dummy4; }; +struct fuse_notify_prune_out { + uint32_t count; + uint32_t padding; + uint64_t spare; +}; + struct fuse_backing_map { int32_t fd; uint32_t flags;