1 files changed, 92 insertions, 19 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 83107be3dd01..d42dff6d5e98 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -556,6 +556,7 @@ EXPORT_SYMBOL_GPL(nfs_setattr);
  * This is a copy of the common vmtruncate, but with the locking
  * corrected to take into account the fact that NFS requires
  * inode->i_size to be updated under the inode->i_lock.
+ * Note: must be called with inode->i_lock held!
  */
 static int nfs_vmtruncate(struct inode * inode, loff_t offset)
 {
@@ -565,14 +566,14 @@ static int nfs_vmtruncate(struct inode * inode, loff_t offset)
         if (err)
                 goto out;
 
-        spin_lock(&inode->i_lock);
         i_size_write(inode, offset);
         /* Optimisation */
         if (offset == 0)
                 NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_DATA;
-        spin_unlock(&inode->i_lock);
 
+        spin_unlock(&inode->i_lock);
         truncate_pagecache(inode, offset);
+        spin_lock(&inode->i_lock);
 out:
         return err;
 }
@@ -585,10 +586,15 @@ out:
  * Note: we do this in the *proc.c in order to ensure that
  *       it works for things like exclusive creates too.
  */
-void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
+void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
+                struct nfs_fattr *fattr)
 {
+        /* Barrier: bump the attribute generation count. */
+        nfs_fattr_set_barrier(fattr);
+
+        spin_lock(&inode->i_lock);
+        NFS_I(inode)->attr_gencount = fattr->gencount;
         if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
-                spin_lock(&inode->i_lock);
                 if ((attr->ia_valid & ATTR_MODE) != 0) {
                         int mode = attr->ia_mode & S_IALLUGO;
                         mode |= inode->i_mode & ~S_IALLUGO;
@@ -600,12 +606,13 @@ void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
                         inode->i_gid = attr->ia_gid;
                 nfs_set_cache_invalid(inode, NFS_INO_INVALID_ACCESS
                                 | NFS_INO_INVALID_ACL);
-                spin_unlock(&inode->i_lock);
         }
         if ((attr->ia_valid & ATTR_SIZE) != 0) {
                 nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
                 nfs_vmtruncate(inode, attr->ia_size);
         }
+        nfs_update_inode(inode, fattr);
+        spin_unlock(&inode->i_lock);
 }
 EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
 
@@ -1028,6 +1035,7 @@ static int nfs_invalidate_mapping(struct inode *inode, struct address_space *map
 
         if (mapping->nrpages != 0) {
                 if (S_ISREG(inode->i_mode)) {
+                        unmap_mapping_range(mapping, 0, 0, 0);
                         ret = nfs_sync_mapping(mapping);
                         if (ret < 0)
                                 return ret;
@@ -1060,11 +1068,14 @@ static bool nfs_mapping_need_revalidate_inode(struct inode *inode)
 }
 
 /**
- * nfs_revalidate_mapping - Revalidate the pagecache
+ * __nfs_revalidate_mapping - Revalidate the pagecache
  * @inode - pointer to host inode
  * @mapping - pointer to mapping
+ * @may_lock - take inode->i_mutex?
  */
-int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
+static int __nfs_revalidate_mapping(struct inode *inode,
+                struct address_space *mapping,
+                bool may_lock)
 {
         struct nfs_inode *nfsi = NFS_I(inode);
         unsigned long *bitlock = &nfsi->flags;
@@ -1113,7 +1124,12 @@ int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
         nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
         spin_unlock(&inode->i_lock);
         trace_nfs_invalidate_mapping_enter(inode);
-        ret = nfs_invalidate_mapping(inode, mapping);
+        if (may_lock) {
+                mutex_lock(&inode->i_mutex);
+                ret = nfs_invalidate_mapping(inode, mapping);
+                mutex_unlock(&inode->i_mutex);
+        } else
+                ret = nfs_invalidate_mapping(inode, mapping);
         trace_nfs_invalidate_mapping_exit(inode, ret);
 
         clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
@@ -1123,6 +1139,29 @@ out:
         return ret;
 }
 
+/**
+ * nfs_revalidate_mapping - Revalidate the pagecache
+ * @inode - pointer to host inode
+ * @mapping - pointer to mapping
+ */
+int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
+{
+        return __nfs_revalidate_mapping(inode, mapping, false);
+}
+
+/**
+ * nfs_revalidate_mapping_protected - Revalidate the pagecache
+ * @inode - pointer to host inode
+ * @mapping - pointer to mapping
+ *
+ * Differs from nfs_revalidate_mapping() in that it grabs the inode->i_mutex
+ * while invalidating the mapping.
+ */
+int nfs_revalidate_mapping_protected(struct inode *inode, struct address_space *mapping)
+{
+        return __nfs_revalidate_mapping(inode, mapping, true);
+}
+
 static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 {
         struct nfs_inode *nfsi = NFS_I(inode);
@@ -1231,13 +1270,6 @@ static int nfs_ctime_need_update(const struct inode *inode, const struct nfs_fat
         return timespec_compare(&fattr->ctime, &inode->i_ctime) > 0;
 }
 
-static int nfs_size_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
-{
-        if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
-                return 0;
-        return nfs_size_to_loff_t(fattr->size) > i_size_read(inode);
-}
-
 static atomic_long_t nfs_attr_generation_counter;
 
 static unsigned long nfs_read_attr_generation_counter(void)
@@ -1249,6 +1281,7 @@ unsigned long nfs_inc_attr_generation_counter(void)
 {
         return atomic_long_inc_return(&nfs_attr_generation_counter);
 }
+EXPORT_SYMBOL_GPL(nfs_inc_attr_generation_counter);
 
 void nfs_fattr_init(struct nfs_fattr *fattr)
 {
@@ -1260,6 +1293,22 @@ void nfs_fattr_init(struct nfs_fattr *fattr)
 }
 EXPORT_SYMBOL_GPL(nfs_fattr_init);
 
+/**
+ * nfs_fattr_set_barrier
+ * @fattr: attributes
+ *
+ * Used to set a barrier after an attribute was updated. This
+ * barrier ensures that older attributes from RPC calls that may
+ * have raced with our update cannot clobber these new values.
+ * Note that you are still responsible for ensuring that other
+ * operations which change the attribute on the server do not
+ * collide.
+ */
+void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
+{
+        fattr->gencount = nfs_inc_attr_generation_counter();
+}
+
 struct nfs_fattr *nfs_alloc_fattr(void)
 {
         struct nfs_fattr *fattr;
@@ -1370,7 +1419,6 @@ static int nfs_inode_attrs_need_update(const struct inode *inode, const struct n
 
         return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
                 nfs_ctime_need_update(inode, fattr) ||
-                nfs_size_need_update(inode, fattr) ||
                 ((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
 }
 
@@ -1460,6 +1508,7 @@ int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
         int status;
 
         spin_lock(&inode->i_lock);
+        nfs_fattr_set_barrier(fattr);
         status = nfs_post_op_update_inode_locked(inode, fattr);
         spin_unlock(&inode->i_lock);
 
@@ -1468,7 +1517,7 @@ int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
 
 /**
- * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
+ * nfs_post_op_update_inode_force_wcc_locked - update the inode attribute cache
  * @inode - pointer to inode
  * @fattr - updated attributes
  *
@@ -1478,11 +1527,10 @@ EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
  *
  * This function is mainly designed to be used by the ->write_done() functions.
  */
-int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
+int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr)
 {
         int status;
 
-        spin_lock(&inode->i_lock);
         /* Don't do a WCC update if these attributes are already stale */
         if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
                         !nfs_inode_attrs_need_update(inode, fattr)) {
@@ -1514,6 +1562,27 @@ int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fa
         }
 out_noforce:
         status = nfs_post_op_update_inode_locked(inode, fattr);
+        return status;
+}
+
+/**
+ * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
+ * @inode - pointer to inode
+ * @fattr - updated attributes
+ *
+ * After an operation that has changed the inode metadata, mark the
+ * attribute cache as being invalid, then try to update it. Fake up
+ * weak cache consistency data, if none exist.
+ *
+ * This function is mainly designed to be used by the ->write_done() functions.
+ */
+int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
+{
+        int status;
+
+        spin_lock(&inode->i_lock);
+        nfs_fattr_set_barrier(fattr);
+        status = nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
         spin_unlock(&inode->i_lock);
         return status;
 }
@@ -1715,6 +1784,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                 nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
                 nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
                 nfsi->attrtimeo_timestamp = now;
+                /* Set barrier to be more recent than all outstanding updates */
                 nfsi->attr_gencount = nfs_inc_attr_generation_counter();
         } else {
                 if (!time_in_range_open(now, nfsi->attrtimeo_timestamp, nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
@@ -1722,6 +1792,9 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                                 nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
                         nfsi->attrtimeo_timestamp = now;
                 }
+                /* Set the barrier to be more recent than this fattr */
+                if ((long)fattr->gencount - (long)nfsi->attr_gencount > 0)
+                        nfsi->attr_gencount = fattr->gencount;
         }
         invalid &= ~NFS_INO_INVALID_ATTR;
         /* Don't invalidate the data if we were to blame */