| Message ID | 20220615031647.1764797-1-asmadeus@codewreck.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | None | expand |
On Mittwoch, 15. Juni 2022 05:16:45 CEST Dominique Martinet wrote: > I was recently reminded that it is not clear that p9_client_clunk() > was actually just decrementing refcount and clunking only when that > reaches zero: make it clear through a set of helpers. > > This will also allow instrumenting refcounting better for debugging > next patch > > Link: > https://lkml.kernel.org/r/20220612085330.1451496-5-asmadeus@codewreck.org > Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com> > Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> > --- > v1 -> v2: p9_fid_get/put are now static inline in .h > v2 -> v3: fix commit message and add comment to helpers > > fs/9p/fid.c | 18 ++++++++-------- > fs/9p/fid.h | 2 +- > fs/9p/vfs_addr.c | 4 ++-- > fs/9p/vfs_dentry.c | 4 ++-- > fs/9p/vfs_dir.c | 2 +- > fs/9p/vfs_file.c | 4 ++-- > fs/9p/vfs_inode.c | 48 ++++++++++++++++++++--------------------- > fs/9p/vfs_inode_dotl.c | 42 ++++++++++++++++++------------------ > fs/9p/vfs_super.c | 6 +++--- > fs/9p/xattr.c | 8 +++---- > include/net/9p/client.h | 28 ++++++++++++++++++++++++ > net/9p/client.c | 15 +++---------- > 12 files changed, 100 insertions(+), 81 deletions(-) > > diff --git a/fs/9p/fid.c b/fs/9p/fid.c > index e8fad28fc5bd..d792499349c4 100644 > --- a/fs/9p/fid.c > +++ b/fs/9p/fid.c > @@ -56,7 +56,7 @@ static struct p9_fid *v9fs_fid_find_inode(struct inode > *inode, kuid_t uid) h = (struct hlist_head *)&inode->i_private; > hlist_for_each_entry(fid, h, ilist) { > if (uid_eq(fid->uid, uid)) { > - refcount_inc(&fid->count); > + p9_fid_get(fid); > ret = fid; > break; > } > @@ -104,7 +104,7 @@ static struct p9_fid *v9fs_fid_find(struct dentry > *dentry, kuid_t uid, int any) hlist_for_each_entry(fid, h, dlist) { > if (any || uid_eq(fid->uid, uid)) { > ret = fid; > - refcount_inc(&ret->count); > + p9_fid_get(ret); > break; > } > } > @@ -172,7 +172,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct > dentry *dentry, old_fid = fid; > > fid = p9_client_walk(old_fid, 1, &dentry->d_name.name, 1); > - p9_client_clunk(old_fid); > + p9_fid_put(old_fid); > goto fid_out; > } > up_read(&v9ses->rename_sem); > @@ -194,7 +194,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct > dentry *dentry, if (IS_ERR(root_fid)) > return root_fid; > > - refcount_inc(&root_fid->count); > + p9_fid_get(root_fid); > v9fs_fid_add(dentry->d_sb->s_root, root_fid); > } > /* If we are root ourself just return that */ > @@ -225,7 +225,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct > dentry *dentry, old_fid == root_fid /* clone */); > /* non-cloning walk will return the same fid */ > if (fid != old_fid) { > - p9_client_clunk(old_fid); > + p9_fid_put(old_fid); > old_fid = fid; > } > if (IS_ERR(fid)) { > @@ -240,11 +240,11 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct > dentry *dentry, spin_lock(&dentry->d_lock); > if (d_unhashed(dentry)) { > spin_unlock(&dentry->d_lock); > - p9_client_clunk(fid); > + p9_fid_put(fid); > fid = ERR_PTR(-ENOENT); > } else { > __add_fid(dentry, fid); > - refcount_inc(&fid->count); > + p9_fid_get(fid); > spin_unlock(&dentry->d_lock); > } > } > @@ -301,7 +301,7 @@ struct p9_fid *v9fs_writeback_fid(struct dentry *dentry) > fid = clone_fid(ofid); > if (IS_ERR(fid)) > goto error_out; > - p9_client_clunk(ofid); > + p9_fid_put(ofid); > /* > * writeback fid will only be used to write back the > * dirty pages. We always request for the open fid in read-write > @@ -310,7 +310,7 @@ struct p9_fid *v9fs_writeback_fid(struct dentry *dentry) > */ > err = p9_client_open(fid, O_RDWR); > if (err < 0) { > - p9_client_clunk(fid); > + p9_fid_put(fid); > fid = ERR_PTR(err); > goto error_out; > } > diff --git a/fs/9p/fid.h b/fs/9p/fid.h > index f7f33509e169..3168dfad510e 100644 > --- a/fs/9p/fid.h > +++ b/fs/9p/fid.h > @@ -29,7 +29,7 @@ static inline struct p9_fid *v9fs_fid_clone(struct dentry > *dentry) return fid; > > nfid = clone_fid(fid); > - p9_client_clunk(fid); > + p9_fid_put(fid); > return nfid; > } > #endif > diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c > index 7f924e671e3e..c5f71eeb28b6 100644 > --- a/fs/9p/vfs_addr.c > +++ b/fs/9p/vfs_addr.c > @@ -70,7 +70,7 @@ static int v9fs_init_request(struct netfs_io_request > *rreq, struct file *file) > > BUG_ON(!fid); > > - refcount_inc(&fid->count); > + p9_fid_get(fid); > rreq->netfs_priv = fid; > return 0; > } > @@ -83,7 +83,7 @@ static void v9fs_free_request(struct netfs_io_request > *rreq) { > struct p9_fid *fid = rreq->netfs_priv; > > - p9_client_clunk(fid); > + p9_fid_put(fid); > } > > /** > diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c > index 1c609e99d280..f89f01734587 100644 > --- a/fs/9p/vfs_dentry.c > +++ b/fs/9p/vfs_dentry.c > @@ -54,7 +54,7 @@ static void v9fs_dentry_release(struct dentry *dentry) > p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n", > dentry, dentry); > hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata) > - p9_client_clunk(hlist_entry(p, struct p9_fid, dlist)); > + p9_fid_put(hlist_entry(p, struct p9_fid, dlist)); > dentry->d_fsdata = NULL; > } > > @@ -85,7 +85,7 @@ static int v9fs_lookup_revalidate(struct dentry *dentry, > unsigned int flags) retval = v9fs_refresh_inode_dotl(fid, inode); > else > retval = v9fs_refresh_inode(fid, inode); > - p9_client_clunk(fid); > + p9_fid_put(fid); > > if (retval == -ENOENT) > return 0; > diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c > index 958680f7f23e..000fbaae9b18 100644 > --- a/fs/9p/vfs_dir.c > +++ b/fs/9p/vfs_dir.c > @@ -218,7 +218,7 @@ int v9fs_dir_release(struct inode *inode, struct file > *filp) spin_lock(&inode->i_lock); > hlist_del(&fid->ilist); > spin_unlock(&inode->i_lock); > - p9_client_clunk(fid); > + p9_fid_put(fid); > } > > if ((filp->f_mode & FMODE_WRITE)) { > diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c > index 2573c08f335c..8276f3af35d7 100644 > --- a/fs/9p/vfs_file.c > +++ b/fs/9p/vfs_file.c > @@ -63,7 +63,7 @@ int v9fs_file_open(struct inode *inode, struct file *file) > > err = p9_client_open(fid, omode); > if (err < 0) { > - p9_client_clunk(fid); > + p9_fid_put(fid); > return err; > } > if ((file->f_flags & O_APPEND) && > @@ -98,7 +98,7 @@ int v9fs_file_open(struct inode *inode, struct file *file) > v9fs_open_fid_add(inode, fid); > return 0; > out_error: > - p9_client_clunk(file->private_data); > + p9_fid_put(file->private_data); > file->private_data = NULL; > return err; > } > diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c > index 3d8297714772..bde18776f0c7 100644 > --- a/fs/9p/vfs_inode.c > +++ b/fs/9p/vfs_inode.c > @@ -400,7 +400,7 @@ void v9fs_evict_inode(struct inode *inode) > fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false); > /* clunk the fid stashed in writeback_fid */ > if (v9inode->writeback_fid) { > - p9_client_clunk(v9inode->writeback_fid); > + p9_fid_put(v9inode->writeback_fid); > v9inode->writeback_fid = NULL; > } > } > @@ -569,7 +569,7 @@ static int v9fs_remove(struct inode *dir, struct dentry > *dentry, int flags) if (v9fs_proto_dotl(v9ses)) > retval = p9_client_unlinkat(dfid, dentry->d_name.name, > v9fs_at_to_dotl_flags(flags)); > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > if (retval == -EOPNOTSUPP) { > /* Try the one based on path */ > v9fid = v9fs_fid_clone(dentry); > @@ -633,14 +633,14 @@ v9fs_create(struct v9fs_session_info *v9ses, struct > inode *dir, if (IS_ERR(ofid)) { > err = PTR_ERR(ofid); > p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err); > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > return ERR_PTR(err); > } > > err = p9_client_fcreate(ofid, name, perm, mode, extension); > if (err < 0) { > p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err); > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > goto error; > } > > @@ -652,7 +652,7 @@ v9fs_create(struct v9fs_session_info *v9ses, struct > inode *dir, p9_debug(P9_DEBUG_VFS, > "p9_client_walk failed %d\n", err); > fid = NULL; > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > goto error; > } > /* > @@ -663,20 +663,20 @@ v9fs_create(struct v9fs_session_info *v9ses, struct > inode *dir, err = PTR_ERR(inode); > p9_debug(P9_DEBUG_VFS, > "inode creation failed %d\n", err); > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > goto error; > } > v9fs_fid_add(dentry, fid); > d_instantiate(dentry, inode); > } > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > return ofid; > error: > if (ofid) > - p9_client_clunk(ofid); > + p9_fid_put(ofid); > > if (fid) > - p9_client_clunk(fid); > + p9_fid_put(fid); > > return ERR_PTR(err); > } > @@ -708,7 +708,7 @@ v9fs_vfs_create(struct user_namespace *mnt_userns, > struct inode *dir, return PTR_ERR(fid); > > v9fs_invalidate_inode_attr(dir); > - p9_client_clunk(fid); > + p9_fid_put(fid); > > return 0; > } > @@ -744,7 +744,7 @@ static int v9fs_vfs_mkdir(struct user_namespace > *mnt_userns, struct inode *dir, } > > if (fid) > - p9_client_clunk(fid); > + p9_fid_put(fid); > > return err; > } > @@ -785,7 +785,7 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct > dentry *dentry, */ > name = dentry->d_name.name; > fid = p9_client_walk(dfid, 1, &name, 1); > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > if (fid == ERR_PTR(-ENOENT)) > inode = NULL; > else if (IS_ERR(fid)) > @@ -808,7 +808,7 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct > dentry *dentry, else if (!IS_ERR(res)) > v9fs_fid_add(res, fid); > else > - p9_client_clunk(fid); > + p9_fid_put(fid); > } > return res; > } > @@ -891,7 +891,7 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry > *dentry, > > error: > if (fid) > - p9_client_clunk(fid); > + p9_fid_put(fid); > goto out; > } > > @@ -959,7 +959,7 @@ v9fs_vfs_rename(struct user_namespace *mnt_userns, > struct inode *old_dir, dfid = v9fs_parent_fid(old_dentry); > olddirfid = clone_fid(dfid); > if (dfid && !IS_ERR(dfid)) > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > > if (IS_ERR(olddirfid)) { > retval = PTR_ERR(olddirfid); > @@ -968,7 +968,7 @@ v9fs_vfs_rename(struct user_namespace *mnt_userns, > struct inode *old_dir, > > dfid = v9fs_parent_fid(new_dentry); > newdirfid = clone_fid(dfid); > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > > if (IS_ERR(newdirfid)) { > retval = PTR_ERR(newdirfid); > @@ -1020,13 +1020,13 @@ v9fs_vfs_rename(struct user_namespace *mnt_userns, > struct inode *old_dir, d_move(old_dentry, new_dentry); > } > up_write(&v9ses->rename_sem); > - p9_client_clunk(newdirfid); > + p9_fid_put(newdirfid); > > clunk_olddir: > - p9_client_clunk(olddirfid); > + p9_fid_put(olddirfid); > > done: > - p9_client_clunk(oldfid); > + p9_fid_put(oldfid); > return retval; > } > > @@ -1060,7 +1060,7 @@ v9fs_vfs_getattr(struct user_namespace *mnt_userns, > const struct path *path, return PTR_ERR(fid); > > st = p9_client_stat(fid); > - p9_client_clunk(fid); > + p9_fid_put(fid); > if (IS_ERR(st)) > return PTR_ERR(st); > > @@ -1136,7 +1136,7 @@ static int v9fs_vfs_setattr(struct user_namespace > *mnt_userns, retval = p9_client_wstat(fid, &wstat); > > if (use_dentry) > - p9_client_clunk(fid); > + p9_fid_put(fid); > > if (retval < 0) > return retval; > @@ -1261,7 +1261,7 @@ static const char *v9fs_vfs_get_link(struct dentry > *dentry, return ERR_CAST(fid); > > st = p9_client_stat(fid); > - p9_client_clunk(fid); > + p9_fid_put(fid); > if (IS_ERR(st)) > return ERR_CAST(st); > > @@ -1308,7 +1308,7 @@ static int v9fs_vfs_mkspecial(struct inode *dir, > struct dentry *dentry, return PTR_ERR(fid); > > v9fs_invalidate_inode_attr(dir); > - p9_client_clunk(fid); > + p9_fid_put(fid); > return 0; > } > > @@ -1364,7 +1364,7 @@ v9fs_vfs_link(struct dentry *old_dentry, struct inode > *dir, v9fs_refresh_inode(oldfid, d_inode(old_dentry)); > v9fs_invalidate_inode_attr(dir); > } > - p9_client_clunk(oldfid); > + p9_fid_put(oldfid); > return retval; > } > > diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c > index b6eb1160296c..09b124fe349c 100644 > --- a/fs/9p/vfs_inode_dotl.c > +++ b/fs/9p/vfs_inode_dotl.c > @@ -274,7 +274,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct > dentry *dentry, if (IS_ERR(ofid)) { > err = PTR_ERR(ofid); > p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err); > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > goto out; > } > > @@ -286,7 +286,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct > dentry *dentry, if (err) { > p9_debug(P9_DEBUG_VFS, "Failed to get acl values in creat %d\n", > err); > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > goto error; > } > err = p9_client_create_dotl(ofid, name, v9fs_open_to_dotl_flags(flags), > @@ -294,14 +294,14 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct > dentry *dentry, if (err < 0) { > p9_debug(P9_DEBUG_VFS, "p9_client_open_dotl failed in creat %d\n", > err); > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > goto error; > } > v9fs_invalidate_inode_attr(dir); > > /* instantiate inode and assign the unopened fid to the dentry */ > fid = p9_client_walk(dfid, 1, &name, 1); > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > if (IS_ERR(fid)) { > err = PTR_ERR(fid); > p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err); > @@ -358,10 +358,10 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct > dentry *dentry, > > error: > if (fid) > - p9_client_clunk(fid); > + p9_fid_put(fid); > err_clunk_old_fid: > if (ofid) > - p9_client_clunk(ofid); > + p9_fid_put(ofid); > goto out; > } > > @@ -458,9 +458,9 @@ static int v9fs_vfs_mkdir_dotl(struct user_namespace > *mnt_userns, v9fs_invalidate_inode_attr(dir); > error: > if (fid) > - p9_client_clunk(fid); > + p9_fid_put(fid); > v9fs_put_acl(dacl, pacl); > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > return err; > } > > @@ -489,7 +489,7 @@ v9fs_vfs_getattr_dotl(struct user_namespace *mnt_userns, > */ > > st = p9_client_getattr_dotl(fid, P9_STATS_ALL); > - p9_client_clunk(fid); > + p9_fid_put(fid); > if (IS_ERR(st)) > return PTR_ERR(st); > > @@ -603,7 +603,7 @@ int v9fs_vfs_setattr_dotl(struct user_namespace > *mnt_userns, retval = p9_client_setattr(fid, &p9attr); > if (retval < 0) { > if (use_dentry) > - p9_client_clunk(fid); > + p9_fid_put(fid); > return retval; > } > > @@ -619,12 +619,12 @@ int v9fs_vfs_setattr_dotl(struct user_namespace > *mnt_userns, retval = v9fs_acl_chmod(inode, fid); > if (retval < 0) { > if (use_dentry) > - p9_client_clunk(fid); > + p9_fid_put(fid); > return retval; > } > } > if (use_dentry) > - p9_client_clunk(fid); > + p9_fid_put(fid); > > return 0; > } > @@ -771,9 +771,9 @@ v9fs_vfs_symlink_dotl(struct user_namespace *mnt_userns, > struct inode *dir, > > error: > if (fid) > - p9_client_clunk(fid); > + p9_fid_put(fid); > > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > return err; > } > > @@ -803,14 +803,14 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct > inode *dir, > > oldfid = v9fs_fid_lookup(old_dentry); > if (IS_ERR(oldfid)) { > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > return PTR_ERR(oldfid); > } > > err = p9_client_link(dfid, oldfid, dentry->d_name.name); > > - p9_client_clunk(dfid); > - p9_client_clunk(oldfid); > + p9_fid_put(dfid); > + p9_fid_put(oldfid); > if (err < 0) { > p9_debug(P9_DEBUG_VFS, "p9_client_link failed %d\n", err); > return err; > @@ -826,7 +826,7 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct > inode *dir, return PTR_ERR(fid); > > v9fs_refresh_inode_dotl(fid, d_inode(old_dentry)); > - p9_client_clunk(fid); > + p9_fid_put(fid); > } > ihold(d_inode(old_dentry)); > d_instantiate(dentry, d_inode(old_dentry)); > @@ -924,9 +924,9 @@ v9fs_vfs_mknod_dotl(struct user_namespace *mnt_userns, > struct inode *dir, } > error: > if (fid) > - p9_client_clunk(fid); > + p9_fid_put(fid); > v9fs_put_acl(dacl, pacl); > - p9_client_clunk(dfid); > + p9_fid_put(dfid); > > return err; > } > @@ -956,7 +956,7 @@ v9fs_vfs_get_link_dotl(struct dentry *dentry, > if (IS_ERR(fid)) > return ERR_CAST(fid); > retval = p9_client_readlink(fid, &target); > - p9_client_clunk(fid); > + p9_fid_put(fid); > if (retval) > return ERR_PTR(retval); > set_delayed_call(done, kfree_link, target); > diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c > index 97e23b4e6982..bf350fad9500 100644 > --- a/fs/9p/vfs_super.c > +++ b/fs/9p/vfs_super.c > @@ -190,7 +190,7 @@ static struct dentry *v9fs_mount(struct file_system_type > *fs_type, int flags, return dget(sb->s_root); > > clunk_fid: > - p9_client_clunk(fid); > + p9_fid_put(fid); > v9fs_session_close(v9ses); > free_session: > kfree(v9ses); > @@ -203,7 +203,7 @@ static struct dentry *v9fs_mount(struct file_system_type > *fs_type, int flags, * attached the fid to dentry so it won't get clunked > * automatically. > */ > - p9_client_clunk(fid); > + p9_fid_put(fid); > deactivate_locked_super(sb); > return ERR_PTR(retval); > } > @@ -270,7 +270,7 @@ static int v9fs_statfs(struct dentry *dentry, struct > kstatfs *buf) } > res = simple_statfs(dentry, buf); > done: > - p9_client_clunk(fid); > + p9_fid_put(fid); > return res; > } > > diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c > index a824441b95a2..1f9298a4bd42 100644 > --- a/fs/9p/xattr.c > +++ b/fs/9p/xattr.c > @@ -44,7 +44,7 @@ ssize_t v9fs_fid_xattr_get(struct p9_fid *fid, const char > *name, if (err) > retval = err; > } > - p9_client_clunk(attr_fid); > + p9_fid_put(attr_fid); > return retval; > } > > @@ -71,7 +71,7 @@ ssize_t v9fs_xattr_get(struct dentry *dentry, const char > *name, if (IS_ERR(fid)) > return PTR_ERR(fid); > ret = v9fs_fid_xattr_get(fid, name, buffer, buffer_size); > - p9_client_clunk(fid); > + p9_fid_put(fid); > > return ret; > } > @@ -98,7 +98,7 @@ int v9fs_xattr_set(struct dentry *dentry, const char > *name, if (IS_ERR(fid)) > return PTR_ERR(fid); > ret = v9fs_fid_xattr_set(fid, name, value, value_len, flags); > - p9_client_clunk(fid); > + p9_fid_put(fid); > return ret; > } > > @@ -128,7 +128,7 @@ int v9fs_fid_xattr_set(struct p9_fid *fid, const char > *name, retval); > else > p9_client_write(fid, 0, &from, &retval); > - err = p9_client_clunk(fid); > + err = p9_fid_put(fid); > if (!retval && err) > retval = err; > return retval; > diff --git a/include/net/9p/client.h b/include/net/9p/client.h > index ec1d1706f43c..eabb53992350 100644 > --- a/include/net/9p/client.h > +++ b/include/net/9p/client.h > @@ -237,6 +237,34 @@ static inline int p9_req_try_get(struct p9_req_t *r) > > int p9_req_put(struct p9_req_t *r); > > +/* fid reference counting helpers: > + * - fids used for any length of time should always be referenced through > + * p9_fid_get(), and released with p9_fid_put() > + * - v9fs_fid_lookup() or similar will automatically call get for you > + * and also require a put > + * - the *_fid_add() helpers will stash the fid in the inode, > + * at which point it is the responsibility of evict_inode() > + * to call the put > + * - the last put will automatically send a clunk to the server > + */ > +static inline struct p9_fid *p9_fid_get(struct p9_fid *fid) > +{ > + refcount_inc(&fid->count); > + > + return fid; > +} > + > +static inline int p9_fid_put(struct p9_fid *fid) > +{ > + if (!fid || IS_ERR(fid)) > + return 0; > + > + if (!refcount_dec_and_test(&fid->count)) > + return 0; > + > + return p9_client_clunk(fid); > +} > + > void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status); > > int p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, > diff --git a/net/9p/client.c b/net/9p/client.c > index 8bba0d9cf975..f3eb280c7d9d 100644 > --- a/net/9p/client.c > +++ b/net/9p/client.c > @@ -1228,7 +1228,7 @@ struct p9_fid *p9_client_walk(struct p9_fid *oldfid, > uint16_t nwname, > > clunk_fid: > kfree(wqids); > - p9_client_clunk(fid); > + p9_fid_put(fid); > fid = NULL; > > error: > @@ -1459,15 +1459,6 @@ int p9_client_clunk(struct p9_fid *fid) > struct p9_req_t *req; > int retries = 0; > > - if (!fid || IS_ERR(fid)) { > - pr_warn("%s (%d): Trying to clunk with invalid fid\n", > - __func__, task_pid_nr(current)); > - dump_stack(); > - return 0; > - } > - if (!refcount_dec_and_test(&fid->count)) > - return 0; > - I probably would have moved (and that way preserved) that sanity warning to p9_fid_put(), but anyway LGTM. Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> > again: > p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", > fid->fid, retries); > @@ -1519,7 +1510,7 @@ int p9_client_remove(struct p9_fid *fid) > p9_tag_remove(clnt, req); > error: > if (err == -ERESTARTSYS) > - p9_client_clunk(fid); > + p9_fid_put(fid); > else > p9_fid_destroy(fid); > return err; > @@ -2042,7 +2033,7 @@ struct p9_fid *p9_client_xattrwalk(struct p9_fid > *file_fid, attr_fid->fid, *attr_size); > return attr_fid; > clunk_fid: > - p9_client_clunk(attr_fid); > + p9_fid_put(attr_fid); > attr_fid = NULL; > error: > if (attr_fid && attr_fid != file_fid)
Christian Schoenebeck wrote on Wed, Jun 15, 2022 at 03:00:19PM +0200: > > - if (!fid || IS_ERR(fid)) { > > - pr_warn("%s (%d): Trying to clunk with invalid fid\n", > > - __func__, task_pid_nr(current)); > > - dump_stack(); > > - return 0; > > - } > > - if (!refcount_dec_and_test(&fid->count)) > > - return 0; > > - > > I probably would have moved (and that way preserved) that sanity warning to > p9_fid_put(), but anyway LGTM. The existing code was careful not to call clunk on error, but I consider put() calls to be kind of like free in that it's better to make these easy to call: this allowed patch 6 reworked most fs/ functions getting a ref to just initialize fids to NULL and inconditionally call p9_fid_put() before return. I guess it's just a matter of preference ultimately, but I think that'll make it a bit easier to not leak fids. Time will tell if this works :) > Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Thanks for this and other reviews! -- Dominique
diff --git a/fs/9p/fid.c b/fs/9p/fid.c index e8fad28fc5bd..d792499349c4 100644 --- a/fs/9p/fid.c +++ b/fs/9p/fid.c @@ -56,7 +56,7 @@ static struct p9_fid *v9fs_fid_find_inode(struct inode *inode, kuid_t uid) h = (struct hlist_head *)&inode->i_private; hlist_for_each_entry(fid, h, ilist) { if (uid_eq(fid->uid, uid)) { - refcount_inc(&fid->count); + p9_fid_get(fid); ret = fid; break; } @@ -104,7 +104,7 @@ static struct p9_fid *v9fs_fid_find(struct dentry *dentry, kuid_t uid, int any) hlist_for_each_entry(fid, h, dlist) { if (any || uid_eq(fid->uid, uid)) { ret = fid; - refcount_inc(&ret->count); + p9_fid_get(ret); break; } } @@ -172,7 +172,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry, old_fid = fid; fid = p9_client_walk(old_fid, 1, &dentry->d_name.name, 1); - p9_client_clunk(old_fid); + p9_fid_put(old_fid); goto fid_out; } up_read(&v9ses->rename_sem); @@ -194,7 +194,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry, if (IS_ERR(root_fid)) return root_fid; - refcount_inc(&root_fid->count); + p9_fid_get(root_fid); v9fs_fid_add(dentry->d_sb->s_root, root_fid); } /* If we are root ourself just return that */ @@ -225,7 +225,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry, old_fid == root_fid /* clone */); /* non-cloning walk will return the same fid */ if (fid != old_fid) { - p9_client_clunk(old_fid); + p9_fid_put(old_fid); old_fid = fid; } if (IS_ERR(fid)) { @@ -240,11 +240,11 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry, spin_lock(&dentry->d_lock); if (d_unhashed(dentry)) { spin_unlock(&dentry->d_lock); - p9_client_clunk(fid); + p9_fid_put(fid); fid = ERR_PTR(-ENOENT); } else { __add_fid(dentry, fid); - refcount_inc(&fid->count); + p9_fid_get(fid); spin_unlock(&dentry->d_lock); } } @@ -301,7 +301,7 @@ struct p9_fid *v9fs_writeback_fid(struct dentry *dentry) fid = clone_fid(ofid); if (IS_ERR(fid)) goto error_out; - p9_client_clunk(ofid); + p9_fid_put(ofid); /* * writeback fid will only be used to write back the * dirty pages. We always request for the open fid in read-write @@ -310,7 +310,7 @@ struct p9_fid *v9fs_writeback_fid(struct dentry *dentry) */ err = p9_client_open(fid, O_RDWR); if (err < 0) { - p9_client_clunk(fid); + p9_fid_put(fid); fid = ERR_PTR(err); goto error_out; } diff --git a/fs/9p/fid.h b/fs/9p/fid.h index f7f33509e169..3168dfad510e 100644 --- a/fs/9p/fid.h +++ b/fs/9p/fid.h @@ -29,7 +29,7 @@ static inline struct p9_fid *v9fs_fid_clone(struct dentry *dentry) return fid; nfid = clone_fid(fid); - p9_client_clunk(fid); + p9_fid_put(fid); return nfid; } #endif diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c index 7f924e671e3e..c5f71eeb28b6 100644 --- a/fs/9p/vfs_addr.c +++ b/fs/9p/vfs_addr.c @@ -70,7 +70,7 @@ static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file) BUG_ON(!fid); - refcount_inc(&fid->count); + p9_fid_get(fid); rreq->netfs_priv = fid; return 0; } @@ -83,7 +83,7 @@ static void v9fs_free_request(struct netfs_io_request *rreq) { struct p9_fid *fid = rreq->netfs_priv; - p9_client_clunk(fid); + p9_fid_put(fid); } /** diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c index 1c609e99d280..f89f01734587 100644 --- a/fs/9p/vfs_dentry.c +++ b/fs/9p/vfs_dentry.c @@ -54,7 +54,7 @@ static void v9fs_dentry_release(struct dentry *dentry) p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n", dentry, dentry); hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata) - p9_client_clunk(hlist_entry(p, struct p9_fid, dlist)); + p9_fid_put(hlist_entry(p, struct p9_fid, dlist)); dentry->d_fsdata = NULL; } @@ -85,7 +85,7 @@ static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags) retval = v9fs_refresh_inode_dotl(fid, inode); else retval = v9fs_refresh_inode(fid, inode); - p9_client_clunk(fid); + p9_fid_put(fid); if (retval == -ENOENT) return 0; diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c index 958680f7f23e..000fbaae9b18 100644 --- a/fs/9p/vfs_dir.c +++ b/fs/9p/vfs_dir.c @@ -218,7 +218,7 @@ int v9fs_dir_release(struct inode *inode, struct file *filp) spin_lock(&inode->i_lock); hlist_del(&fid->ilist); spin_unlock(&inode->i_lock); - p9_client_clunk(fid); + p9_fid_put(fid); } if ((filp->f_mode & FMODE_WRITE)) { diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 2573c08f335c..8276f3af35d7 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -63,7 +63,7 @@ int v9fs_file_open(struct inode *inode, struct file *file) err = p9_client_open(fid, omode); if (err < 0) { - p9_client_clunk(fid); + p9_fid_put(fid); return err; } if ((file->f_flags & O_APPEND) && @@ -98,7 +98,7 @@ int v9fs_file_open(struct inode *inode, struct file *file) v9fs_open_fid_add(inode, fid); return 0; out_error: - p9_client_clunk(file->private_data); + p9_fid_put(file->private_data); file->private_data = NULL; return err; } diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 3d8297714772..bde18776f0c7 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -400,7 +400,7 @@ void v9fs_evict_inode(struct inode *inode) fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false); /* clunk the fid stashed in writeback_fid */ if (v9inode->writeback_fid) { - p9_client_clunk(v9inode->writeback_fid); + p9_fid_put(v9inode->writeback_fid); v9inode->writeback_fid = NULL; } } @@ -569,7 +569,7 @@ static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags) if (v9fs_proto_dotl(v9ses)) retval = p9_client_unlinkat(dfid, dentry->d_name.name, v9fs_at_to_dotl_flags(flags)); - p9_client_clunk(dfid); + p9_fid_put(dfid); if (retval == -EOPNOTSUPP) { /* Try the one based on path */ v9fid = v9fs_fid_clone(dentry); @@ -633,14 +633,14 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir, if (IS_ERR(ofid)) { err = PTR_ERR(ofid); p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err); - p9_client_clunk(dfid); + p9_fid_put(dfid); return ERR_PTR(err); } err = p9_client_fcreate(ofid, name, perm, mode, extension); if (err < 0) { p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err); - p9_client_clunk(dfid); + p9_fid_put(dfid); goto error; } @@ -652,7 +652,7 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir, p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err); fid = NULL; - p9_client_clunk(dfid); + p9_fid_put(dfid); goto error; } /* @@ -663,20 +663,20 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir, err = PTR_ERR(inode); p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n", err); - p9_client_clunk(dfid); + p9_fid_put(dfid); goto error; } v9fs_fid_add(dentry, fid); d_instantiate(dentry, inode); } - p9_client_clunk(dfid); + p9_fid_put(dfid); return ofid; error: if (ofid) - p9_client_clunk(ofid); + p9_fid_put(ofid); if (fid) - p9_client_clunk(fid); + p9_fid_put(fid); return ERR_PTR(err); } @@ -708,7 +708,7 @@ v9fs_vfs_create(struct user_namespace *mnt_userns, struct inode *dir, return PTR_ERR(fid); v9fs_invalidate_inode_attr(dir); - p9_client_clunk(fid); + p9_fid_put(fid); return 0; } @@ -744,7 +744,7 @@ static int v9fs_vfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir, } if (fid) - p9_client_clunk(fid); + p9_fid_put(fid); return err; } @@ -785,7 +785,7 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, */ name = dentry->d_name.name; fid = p9_client_walk(dfid, 1, &name, 1); - p9_client_clunk(dfid); + p9_fid_put(dfid); if (fid == ERR_PTR(-ENOENT)) inode = NULL; else if (IS_ERR(fid)) @@ -808,7 +808,7 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, else if (!IS_ERR(res)) v9fs_fid_add(res, fid); else - p9_client_clunk(fid); + p9_fid_put(fid); } return res; } @@ -891,7 +891,7 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, error: if (fid) - p9_client_clunk(fid); + p9_fid_put(fid); goto out; } @@ -959,7 +959,7 @@ v9fs_vfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir, dfid = v9fs_parent_fid(old_dentry); olddirfid = clone_fid(dfid); if (dfid && !IS_ERR(dfid)) - p9_client_clunk(dfid); + p9_fid_put(dfid); if (IS_ERR(olddirfid)) { retval = PTR_ERR(olddirfid); @@ -968,7 +968,7 @@ v9fs_vfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir, dfid = v9fs_parent_fid(new_dentry); newdirfid = clone_fid(dfid); - p9_client_clunk(dfid); + p9_fid_put(dfid); if (IS_ERR(newdirfid)) { retval = PTR_ERR(newdirfid); @@ -1020,13 +1020,13 @@ v9fs_vfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir, d_move(old_dentry, new_dentry); } up_write(&v9ses->rename_sem); - p9_client_clunk(newdirfid); + p9_fid_put(newdirfid); clunk_olddir: - p9_client_clunk(olddirfid); + p9_fid_put(olddirfid); done: - p9_client_clunk(oldfid); + p9_fid_put(oldfid); return retval; } @@ -1060,7 +1060,7 @@ v9fs_vfs_getattr(struct user_namespace *mnt_userns, const struct path *path, return PTR_ERR(fid); st = p9_client_stat(fid); - p9_client_clunk(fid); + p9_fid_put(fid); if (IS_ERR(st)) return PTR_ERR(st); @@ -1136,7 +1136,7 @@ static int v9fs_vfs_setattr(struct user_namespace *mnt_userns, retval = p9_client_wstat(fid, &wstat); if (use_dentry) - p9_client_clunk(fid); + p9_fid_put(fid); if (retval < 0) return retval; @@ -1261,7 +1261,7 @@ static const char *v9fs_vfs_get_link(struct dentry *dentry, return ERR_CAST(fid); st = p9_client_stat(fid); - p9_client_clunk(fid); + p9_fid_put(fid); if (IS_ERR(st)) return ERR_CAST(st); @@ -1308,7 +1308,7 @@ static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry, return PTR_ERR(fid); v9fs_invalidate_inode_attr(dir); - p9_client_clunk(fid); + p9_fid_put(fid); return 0; } @@ -1364,7 +1364,7 @@ v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir, v9fs_refresh_inode(oldfid, d_inode(old_dentry)); v9fs_invalidate_inode_attr(dir); } - p9_client_clunk(oldfid); + p9_fid_put(oldfid); return retval; } diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c index b6eb1160296c..09b124fe349c 100644 --- a/fs/9p/vfs_inode_dotl.c +++ b/fs/9p/vfs_inode_dotl.c @@ -274,7 +274,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry, if (IS_ERR(ofid)) { err = PTR_ERR(ofid); p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err); - p9_client_clunk(dfid); + p9_fid_put(dfid); goto out; } @@ -286,7 +286,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry, if (err) { p9_debug(P9_DEBUG_VFS, "Failed to get acl values in creat %d\n", err); - p9_client_clunk(dfid); + p9_fid_put(dfid); goto error; } err = p9_client_create_dotl(ofid, name, v9fs_open_to_dotl_flags(flags), @@ -294,14 +294,14 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry, if (err < 0) { p9_debug(P9_DEBUG_VFS, "p9_client_open_dotl failed in creat %d\n", err); - p9_client_clunk(dfid); + p9_fid_put(dfid); goto error; } v9fs_invalidate_inode_attr(dir); /* instantiate inode and assign the unopened fid to the dentry */ fid = p9_client_walk(dfid, 1, &name, 1); - p9_client_clunk(dfid); + p9_fid_put(dfid); if (IS_ERR(fid)) { err = PTR_ERR(fid); p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err); @@ -358,10 +358,10 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry, error: if (fid) - p9_client_clunk(fid); + p9_fid_put(fid); err_clunk_old_fid: if (ofid) - p9_client_clunk(ofid); + p9_fid_put(ofid); goto out; } @@ -458,9 +458,9 @@ static int v9fs_vfs_mkdir_dotl(struct user_namespace *mnt_userns, v9fs_invalidate_inode_attr(dir); error: if (fid) - p9_client_clunk(fid); + p9_fid_put(fid); v9fs_put_acl(dacl, pacl); - p9_client_clunk(dfid); + p9_fid_put(dfid); return err; } @@ -489,7 +489,7 @@ v9fs_vfs_getattr_dotl(struct user_namespace *mnt_userns, */ st = p9_client_getattr_dotl(fid, P9_STATS_ALL); - p9_client_clunk(fid); + p9_fid_put(fid); if (IS_ERR(st)) return PTR_ERR(st); @@ -603,7 +603,7 @@ int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns, retval = p9_client_setattr(fid, &p9attr); if (retval < 0) { if (use_dentry) - p9_client_clunk(fid); + p9_fid_put(fid); return retval; } @@ -619,12 +619,12 @@ int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns, retval = v9fs_acl_chmod(inode, fid); if (retval < 0) { if (use_dentry) - p9_client_clunk(fid); + p9_fid_put(fid); return retval; } } if (use_dentry) - p9_client_clunk(fid); + p9_fid_put(fid); return 0; } @@ -771,9 +771,9 @@ v9fs_vfs_symlink_dotl(struct user_namespace *mnt_userns, struct inode *dir, error: if (fid) - p9_client_clunk(fid); + p9_fid_put(fid); - p9_client_clunk(dfid); + p9_fid_put(dfid); return err; } @@ -803,14 +803,14 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir, oldfid = v9fs_fid_lookup(old_dentry); if (IS_ERR(oldfid)) { - p9_client_clunk(dfid); + p9_fid_put(dfid); return PTR_ERR(oldfid); } err = p9_client_link(dfid, oldfid, dentry->d_name.name); - p9_client_clunk(dfid); - p9_client_clunk(oldfid); + p9_fid_put(dfid); + p9_fid_put(oldfid); if (err < 0) { p9_debug(P9_DEBUG_VFS, "p9_client_link failed %d\n", err); return err; @@ -826,7 +826,7 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir, return PTR_ERR(fid); v9fs_refresh_inode_dotl(fid, d_inode(old_dentry)); - p9_client_clunk(fid); + p9_fid_put(fid); } ihold(d_inode(old_dentry)); d_instantiate(dentry, d_inode(old_dentry)); @@ -924,9 +924,9 @@ v9fs_vfs_mknod_dotl(struct user_namespace *mnt_userns, struct inode *dir, } error: if (fid) - p9_client_clunk(fid); + p9_fid_put(fid); v9fs_put_acl(dacl, pacl); - p9_client_clunk(dfid); + p9_fid_put(dfid); return err; } @@ -956,7 +956,7 @@ v9fs_vfs_get_link_dotl(struct dentry *dentry, if (IS_ERR(fid)) return ERR_CAST(fid); retval = p9_client_readlink(fid, &target); - p9_client_clunk(fid); + p9_fid_put(fid); if (retval) return ERR_PTR(retval); set_delayed_call(done, kfree_link, target); diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c index 97e23b4e6982..bf350fad9500 100644 --- a/fs/9p/vfs_super.c +++ b/fs/9p/vfs_super.c @@ -190,7 +190,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, return dget(sb->s_root); clunk_fid: - p9_client_clunk(fid); + p9_fid_put(fid); v9fs_session_close(v9ses); free_session: kfree(v9ses); @@ -203,7 +203,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, * attached the fid to dentry so it won't get clunked * automatically. */ - p9_client_clunk(fid); + p9_fid_put(fid); deactivate_locked_super(sb); return ERR_PTR(retval); } @@ -270,7 +270,7 @@ static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) } res = simple_statfs(dentry, buf); done: - p9_client_clunk(fid); + p9_fid_put(fid); return res; } diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c index a824441b95a2..1f9298a4bd42 100644 --- a/fs/9p/xattr.c +++ b/fs/9p/xattr.c @@ -44,7 +44,7 @@ ssize_t v9fs_fid_xattr_get(struct p9_fid *fid, const char *name, if (err) retval = err; } - p9_client_clunk(attr_fid); + p9_fid_put(attr_fid); return retval; } @@ -71,7 +71,7 @@ ssize_t v9fs_xattr_get(struct dentry *dentry, const char *name, if (IS_ERR(fid)) return PTR_ERR(fid); ret = v9fs_fid_xattr_get(fid, name, buffer, buffer_size); - p9_client_clunk(fid); + p9_fid_put(fid); return ret; } @@ -98,7 +98,7 @@ int v9fs_xattr_set(struct dentry *dentry, const char *name, if (IS_ERR(fid)) return PTR_ERR(fid); ret = v9fs_fid_xattr_set(fid, name, value, value_len, flags); - p9_client_clunk(fid); + p9_fid_put(fid); return ret; } @@ -128,7 +128,7 @@ int v9fs_fid_xattr_set(struct p9_fid *fid, const char *name, retval); else p9_client_write(fid, 0, &from, &retval); - err = p9_client_clunk(fid); + err = p9_fid_put(fid); if (!retval && err) retval = err; return retval; diff --git a/include/net/9p/client.h b/include/net/9p/client.h index ec1d1706f43c..eabb53992350 100644 --- a/include/net/9p/client.h +++ b/include/net/9p/client.h @@ -237,6 +237,34 @@ static inline int p9_req_try_get(struct p9_req_t *r) int p9_req_put(struct p9_req_t *r); +/* fid reference counting helpers: + * - fids used for any length of time should always be referenced through + * p9_fid_get(), and released with p9_fid_put() + * - v9fs_fid_lookup() or similar will automatically call get for you + * and also require a put + * - the *_fid_add() helpers will stash the fid in the inode, + * at which point it is the responsibility of evict_inode() + * to call the put + * - the last put will automatically send a clunk to the server + */ +static inline struct p9_fid *p9_fid_get(struct p9_fid *fid) +{ + refcount_inc(&fid->count); + + return fid; +} + +static inline int p9_fid_put(struct p9_fid *fid) +{ + if (!fid || IS_ERR(fid)) + return 0; + + if (!refcount_dec_and_test(&fid->count)) + return 0; + + return p9_client_clunk(fid); +} + void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status); int p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, diff --git a/net/9p/client.c b/net/9p/client.c index 8bba0d9cf975..f3eb280c7d9d 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -1228,7 +1228,7 @@ struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname, clunk_fid: kfree(wqids); - p9_client_clunk(fid); + p9_fid_put(fid); fid = NULL; error: @@ -1459,15 +1459,6 @@ int p9_client_clunk(struct p9_fid *fid) struct p9_req_t *req; int retries = 0; - if (!fid || IS_ERR(fid)) { - pr_warn("%s (%d): Trying to clunk with invalid fid\n", - __func__, task_pid_nr(current)); - dump_stack(); - return 0; - } - if (!refcount_dec_and_test(&fid->count)) - return 0; - again: p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid, retries); @@ -1519,7 +1510,7 @@ int p9_client_remove(struct p9_fid *fid) p9_tag_remove(clnt, req); error: if (err == -ERESTARTSYS) - p9_client_clunk(fid); + p9_fid_put(fid); else p9_fid_destroy(fid); return err; @@ -2042,7 +2033,7 @@ struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid, attr_fid->fid, *attr_size); return attr_fid; clunk_fid: - p9_client_clunk(attr_fid); + p9_fid_put(attr_fid); attr_fid = NULL; error: if (attr_fid && attr_fid != file_fid)