afs: Fix whole-volume callback handling

It's possible for an AFS file server to issue a whole-volume notification
that callbacks on all the vnodes in the file have been broken.  This is
done for R/O and backup volumes (which don't have per-file callbacks) and
for things like a volume being taken offline.

Fix callback handling to detect whole-volume notifications, to track it
across operations and to check it during inode validation.

Fixes: c435ee34551e ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>

diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index 0933294..571437d 100644 (file)
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -113,6 +113,7 @@ again:
        old = vnode->cb_interest;
        vnode->cb_interest = cbi;
        vnode->cb_s_break = cbi->server->cb_s_break;
+       vnode->cb_v_break = vnode->volume->cb_v_break;
        clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
 
        write_sequnlock(&vnode->cb_lock);
@@ -195,13 +196,24 @@ static void afs_break_one_callback(struct afs_server *server,
                if (cbi->vid != fid->vid)
                        continue;
 
-               data.volume = NULL;
-               data.fid = *fid;
-               inode = ilookup5_nowait(cbi->sb, fid->vnode, afs_iget5_test, &data);
-               if (inode) {
-                       vnode = AFS_FS_I(inode);
-                       afs_break_callback(vnode);
-                       iput(inode);
+               if (fid->vnode == 0 && fid->unique == 0) {
+                       /* The callback break applies to an entire volume. */
+                       struct afs_super_info *as = AFS_FS_S(cbi->sb);
+                       struct afs_volume *volume = as->volume;
+
+                       write_lock(&volume->cb_break_lock);
+                       volume->cb_v_break++;
+                       write_unlock(&volume->cb_break_lock);
+               } else {
+                       data.volume = NULL;
+                       data.fid = *fid;
+                       inode = ilookup5_nowait(cbi->sb, fid->vnode,
+                                               afs_iget5_test, &data);
+                       if (inode) {
+                               vnode = AFS_FS_I(inode);
+                               afs_break_callback(vnode);
+                               iput(inode);
+                       }
                }
        }
 
@@ -219,6 +231,8 @@ void afs_break_callbacks(struct afs_server *server, size_t count,
        ASSERT(server != NULL);
        ASSERTCMP(count, <=, AFSCBMAX);
 
+       /* TODO: Sort the callback break list by volume ID */
+
        for (; count > 0; callbacks++, count--) {
                _debug("- Fid { vl=%08x n=%u u=%u }  CB { v=%u x=%u t=%u }",
                       callbacks->fid.vid,

diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 2853acd..7d62300 100644 (file)
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -1141,7 +1141,7 @@ static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
        ret = -ERESTARTSYS;
        if (afs_begin_vnode_operation(&fc, dvnode, key)) {
                while (afs_select_fileserver(&fc)) {
-                       fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(dvnode);
                        afs_fs_create(&fc, dentry->d_name.name, mode, data_version,
                                      &newfid, &newstatus, &newcb);
                }
@@ -1211,7 +1211,7 @@ static int afs_rmdir(struct inode *dir, struct dentry *dentry)
        ret = -ERESTARTSYS;
        if (afs_begin_vnode_operation(&fc, dvnode, key)) {
                while (afs_select_fileserver(&fc)) {
-                       fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(dvnode);
                        afs_fs_remove(&fc, dentry->d_name.name, true,
                                      data_version);
                }
@@ -1314,7 +1314,7 @@ static int afs_unlink(struct inode *dir, struct dentry *dentry)
        ret = -ERESTARTSYS;
        if (afs_begin_vnode_operation(&fc, dvnode, key)) {
                while (afs_select_fileserver(&fc)) {
-                       fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(dvnode);
                        afs_fs_remove(&fc, dentry->d_name.name, false,
                                      data_version);
                }
@@ -1371,7 +1371,7 @@ static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
        ret = -ERESTARTSYS;
        if (afs_begin_vnode_operation(&fc, dvnode, key)) {
                while (afs_select_fileserver(&fc)) {
-                       fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(dvnode);
                        afs_fs_create(&fc, dentry->d_name.name, mode, data_version,
                                      &newfid, &newstatus, &newcb);
                }
@@ -1441,8 +1441,8 @@ static int afs_link(struct dentry *from, struct inode *dir,
                }
 
                while (afs_select_fileserver(&fc)) {
-                       fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
-                       fc.cb_break_2 = vnode->cb_break + vnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(dvnode);
+                       fc.cb_break_2 = afs_calc_vnode_cb_break(vnode);
                        afs_fs_link(&fc, vnode, dentry->d_name.name, data_version);
                }
 
@@ -1510,7 +1510,7 @@ static int afs_symlink(struct inode *dir, struct dentry *dentry,
        ret = -ERESTARTSYS;
        if (afs_begin_vnode_operation(&fc, dvnode, key)) {
                while (afs_select_fileserver(&fc)) {
-                       fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(dvnode);
                        afs_fs_symlink(&fc, dentry->d_name.name,
                                       content, data_version,
                                       &newfid, &newstatus);
@@ -1586,8 +1586,8 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
                        }
                }
                while (afs_select_fileserver(&fc)) {
-                       fc.cb_break = orig_dvnode->cb_break + orig_dvnode->cb_s_break;
-                       fc.cb_break_2 = new_dvnode->cb_break + new_dvnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(orig_dvnode);
+                       fc.cb_break_2 = afs_calc_vnode_cb_break(new_dvnode);
                        afs_fs_rename(&fc, old_dentry->d_name.name,
                                      new_dvnode, new_dentry->d_name.name,
                                      orig_data_version, new_data_version);

diff --git a/fs/afs/file.c b/fs/afs/file.c
index c24c080..7d4f261 100644 (file)
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -238,7 +238,7 @@ int afs_fetch_data(struct afs_vnode *vnode, struct key *key, struct afs_read *de
        ret = -ERESTARTSYS;
        if (afs_begin_vnode_operation(&fc, vnode, key)) {
                while (afs_select_fileserver(&fc)) {
-                       fc.cb_break = vnode->cb_break + vnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(vnode);
                        afs_fs_fetch_data(&fc, desc);
                }
 

diff --git a/fs/afs/flock.c b/fs/afs/flock.c
index 7a0e017..dc62d15 100644 (file)
--- a/fs/afs/flock.c
+++ b/fs/afs/flock.c
@@ -86,7 +86,7 @@ static int afs_set_lock(struct afs_vnode *vnode, struct key *key,
        ret = -ERESTARTSYS;
        if (afs_begin_vnode_operation(&fc, vnode, key)) {
                while (afs_select_fileserver(&fc)) {
-                       fc.cb_break = vnode->cb_break + vnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(vnode);
                        afs_fs_set_lock(&fc, type);
                }
 
@@ -117,7 +117,7 @@ static int afs_extend_lock(struct afs_vnode *vnode, struct key *key)
        ret = -ERESTARTSYS;
        if (afs_begin_vnode_operation(&fc, vnode, key)) {
                while (afs_select_current_fileserver(&fc)) {
-                       fc.cb_break = vnode->cb_break + vnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(vnode);
                        afs_fs_extend_lock(&fc);
                }
 
@@ -148,7 +148,7 @@ static int afs_release_lock(struct afs_vnode *vnode, struct key *key)
        ret = -ERESTARTSYS;
        if (afs_begin_vnode_operation(&fc, vnode, key)) {
                while (afs_select_current_fileserver(&fc)) {
-                       fc.cb_break = vnode->cb_break + vnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(vnode);
                        afs_fs_release_lock(&fc);
                }
 

diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index d16f26c..b273e1d 100644 (file)
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -261,7 +261,7 @@ static void xdr_decode_AFSCallBack(struct afs_call *call,
 
        write_seqlock(&vnode->cb_lock);
 
-       if (call->cb_break == (vnode->cb_break + cbi->server->cb_s_break)) {
+       if (call->cb_break == afs_cb_break_sum(vnode, cbi)) {
                vnode->cb_version       = ntohl(*bp++);
                cb_expiry               = ntohl(*bp++);
                vnode->cb_type          = ntohl(*bp++);

diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index e855c6e..479b7fd 100644 (file)
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -108,7 +108,7 @@ int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool new_inode)
        ret = -ERESTARTSYS;
        if (afs_begin_vnode_operation(&fc, vnode, key)) {
                while (afs_select_fileserver(&fc)) {
-                       fc.cb_break = vnode->cb_break + vnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(vnode);
                        afs_fs_fetch_file_status(&fc, NULL, new_inode);
                }
 
@@ -393,15 +393,18 @@ int afs_validate(struct afs_vnode *vnode, struct key *key)
        read_seqlock_excl(&vnode->cb_lock);
 
        if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
-               if (vnode->cb_s_break != vnode->cb_interest->server->cb_s_break) {
+               if (vnode->cb_s_break != vnode->cb_interest->server->cb_s_break ||
+                   vnode->cb_v_break != vnode->volume->cb_v_break) {
                        vnode->cb_s_break = vnode->cb_interest->server->cb_s_break;
+                       vnode->cb_v_break = vnode->volume->cb_v_break;
+                       valid = false;
                } else if (vnode->status.type == AFS_FTYPE_DIR &&
                           test_bit(AFS_VNODE_DIR_VALID, &vnode->flags) &&
                           vnode->cb_expires_at - 10 > now) {
-                               valid = true;
+                       valid = true;
                } else if (!test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags) &&
                           vnode->cb_expires_at - 10 > now) {
-                               valid = true;
+                       valid = true;
                }
        } else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
                valid = true;
@@ -574,7 +577,7 @@ int afs_setattr(struct dentry *dentry, struct iattr *attr)
        ret = -ERESTARTSYS;
        if (afs_begin_vnode_operation(&fc, vnode, key)) {
                while (afs_select_fileserver(&fc)) {
-                       fc.cb_break = vnode->cb_break + vnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(vnode);
                        afs_fs_setattr(&fc, attr);
                }
 

diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index e75e57e..e3f8a46 100644 (file)
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -461,6 +461,9 @@ struct afs_volume {
        rwlock_t                servers_lock;   /* Lock for ->servers */
        unsigned int            servers_seq;    /* Incremented each time ->servers changes */
 
+       unsigned                cb_v_break;     /* Break-everything counter. */
+       rwlock_t                cb_break_lock;
+
        afs_voltype_t           type;           /* type of volume */
        short                   error;
        char                    type_force;     /* force volume type (suppress R/O -> R/W) */
@@ -521,6 +524,7 @@ struct afs_vnode {
        /* outstanding callback notification on this file */
        struct afs_cb_interest  *cb_interest;   /* Server on which this resides */
        unsigned int            cb_s_break;     /* Mass break counter on ->server */
+       unsigned int            cb_v_break;     /* Mass break counter on ->volume */
        unsigned int            cb_break;       /* Break counter on vnode */
        seqlock_t               cb_lock;        /* Lock for ->cb_interest, ->status, ->cb_*break */
 
@@ -662,6 +666,17 @@ static inline struct afs_cb_interest *afs_get_cb_interest(struct afs_cb_interest
        return cbi;
 }
 
+static inline unsigned int afs_calc_vnode_cb_break(struct afs_vnode *vnode)
+{
+       return vnode->cb_break + vnode->cb_s_break + vnode->cb_v_break;
+}
+
+static inline unsigned int afs_cb_break_sum(struct afs_vnode *vnode,
+                                           struct afs_cb_interest *cbi)
+{
+       return vnode->cb_break + cbi->server->cb_s_break + vnode->volume->cb_v_break;
+}
+
 /*
  * cell.c
  */

diff --git a/fs/afs/security.c b/fs/afs/security.c
index cea2fff..1992b0f 100644 (file)
--- a/fs/afs/security.c
+++ b/fs/afs/security.c
@@ -147,8 +147,7 @@ void afs_cache_permit(struct afs_vnode *vnode, struct key *key,
                                        break;
                                }
 
-                               if (cb_break != (vnode->cb_break +
-                                                vnode->cb_interest->server->cb_s_break)) {
+                               if (cb_break != afs_cb_break_sum(vnode, vnode->cb_interest)) {
                                        changed = true;
                                        break;
                                }
@@ -178,7 +177,7 @@ void afs_cache_permit(struct afs_vnode *vnode, struct key *key,
                }
        }
 
-       if (cb_break != (vnode->cb_break + vnode->cb_interest->server->cb_s_break))
+       if (cb_break != afs_cb_break_sum(vnode, vnode->cb_interest))
                goto someone_else_changed_it;
 
        /* We need a ref on any permits list we want to copy as we'll have to
@@ -257,7 +256,7 @@ found:
 
        spin_lock(&vnode->lock);
        zap = rcu_access_pointer(vnode->permit_cache);
-       if (cb_break == (vnode->cb_break + vnode->cb_interest->server->cb_s_break) &&
+       if (cb_break == afs_cb_break_sum(vnode, vnode->cb_interest) &&
            zap == permits)
                rcu_assign_pointer(vnode->permit_cache, replacement);
        else

diff --git a/fs/afs/super.c b/fs/afs/super.c
index b02838c..9e5d796 100644 (file)
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -688,7 +688,7 @@ static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
        if (afs_begin_vnode_operation(&fc, vnode, key)) {
                fc.flags |= AFS_FS_CURSOR_NO_VSLEEP;
                while (afs_select_fileserver(&fc)) {
-                       fc.cb_break = vnode->cb_break + vnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(vnode);
                        afs_fs_get_volume_status(&fc, &vs);
                }
 

diff --git a/fs/afs/write.c b/fs/afs/write.c
index c164698..8b39e6e 100644 (file)
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -351,7 +351,7 @@ found_key:
        ret = -ERESTARTSYS;
        if (afs_begin_vnode_operation(&fc, vnode, wbk->key)) {
                while (afs_select_fileserver(&fc)) {
-                       fc.cb_break = vnode->cb_break + vnode->cb_s_break;
+                       fc.cb_break = afs_calc_vnode_cb_break(vnode);
                        afs_fs_store_data(&fc, mapping, first, last, offset, to);
                }