- modify dentry revalidation algorithm to check inode/connection
generations. If them are not equal then perform revalidation.
remark: during forced dentry revalidation we are sending FUSE_LOOKUP
request to the userspace daemon and if it return the same inode after
lookup then we can "upgrade" inode connection generation without
invalidating it.
- don't send FUSE_FSYNC, FUSE_RELEASE, etc requests to the userspace
daemon about stale inodes (this can confuse libfuse)
Cc: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Amir Goldstein <amir73il@xxxxxxxxx>
Cc: Stéphane Graber <stgraber@xxxxxxxxxx>
Cc: Seth Forshee <sforshee@xxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: Andrei Vagin <avagin@xxxxxxxxx>
Cc: Pavel Tikhomirov <ptikhomirov@xxxxxxxxxxxxx>
Cc: Bernd Schubert <bschubert@xxxxxxx>
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: criu@xxxxxxxxxx
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@xxxxxxxxxxxxx>
---
fs/fuse/dir.c | 4 +++-
fs/fuse/file.c | 13 ++++++++++---
fs/fuse/fuse_i.h | 3 ++-
fs/fuse/inode.c | 2 +-
4 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index bfbe59e8fce2..d0fdf7289d56 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -213,7 +213,8 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
inode = d_inode_rcu(entry);
if (inode && fuse_is_bad(inode))
goto invalid;
- else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) ||
+ else if ((inode && fuse_stale_inode_conn(inode)) ||
+ time_before64(fuse_dentry_time(entry), get_jiffies_64()) ||
(flags & (LOOKUP_EXCL | LOOKUP_REVAL | LOOKUP_RENAME_TARGET))) {
struct fuse_entry_out outarg;
FUSE_ARGS(args);
@@ -255,6 +256,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
}
spin_lock(&fi->lock);
fi->nlookup++;
+ fi->conn_gen = READ_ONCE(get_fuse_conn(inode)->conn_gen);
spin_unlock(&fi->lock);
}
kfree(forget);
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 742f90b4e638..b977d087b925 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -111,8 +111,14 @@ static void fuse_file_put(struct fuse_file *ff, bool sync, bool isdir)
if (refcount_dec_and_test(&ff->count)) {
struct fuse_args *args = &ff->release_args->args;
- if (isdir ? ff->fm->fc->flags.no_opendir : ff->fm->fc->flags.no_open) {
- /* Do nothing when client does not implement 'open' */
+ if (fuse_stale_ff(ff) ||
+ (isdir ? ff->fm->fc->flags.no_opendir : ff->fm->fc->flags.no_open)) {
+ /*
+ * Do nothing when client does not implement 'open' OR
+ * file descriptor was opened in the previous connection generation,
+ * so, current daemon likely not aware of this FD, let's just skip
+ * FUSE_RELEASE(DIR) request.
+ */
fuse_release_end(ff->fm, args, 0);
} else if (sync) {
fuse_simple_request(ff->fm, args);
@@ -598,9 +604,10 @@ static int fuse_fsync(struct file *file, loff_t start, loff_t end,
{
struct inode *inode = file->f_mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_file *ff = file->private_data;
int err;
- if (fuse_is_bad(inode))
+ if (fuse_stale_ff(ff) || fuse_is_bad(inode))
return -EIO;
inode_lock(inode);
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 943d5011dfa0..90c5b3459864 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -957,7 +957,8 @@ static inline bool fuse_stale_inode(const struct inode *inode, int generation,
struct fuse_attr *attr)
{
return inode->i_generation != generation ||
- inode_wrong_type(inode, attr->mode);
+ inode_wrong_type(inode, attr->mode) ||
+ fuse_stale_inode_conn(inode);
}
static inline void fuse_make_bad(struct inode *inode)
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 389bea6e4a69..26a4149f6db7 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -124,7 +124,7 @@ static void fuse_evict_inode(struct inode *inode)
fuse_dax_inode_cleanup(inode);
if (fi->nlookup) {
fuse_queue_forget(fc, fi->forget, fi->nodeid,
- fi->nlookup, false);
+ fi->nlookup, fuse_stale_inode_conn(inode));
fi->forget = NULL;
}
}
--
2.34.1
