9 files changed, 319 insertions, 8 deletions

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 7219a86d34c..e15fc7d5082 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -244,6 +244,10 @@ static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
         .flags          = 0,
 };
 
+static struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = {
+        .flags          = 0,
+};
+
 static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
         .get_osb        = ocfs2_get_dentry_osb,
         .post_unlock    = ocfs2_dentry_post_unlock,
@@ -622,6 +626,17 @@ static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
                                    &ocfs2_rename_lops, osb);
 }
 
+static void ocfs2_nfs_sync_lock_res_init(struct ocfs2_lock_res *res,
+                                         struct ocfs2_super *osb)
+{
+        /* nfs_sync lockres doesn't come from a slab so we call init
+         * once on it manually.  */
+        ocfs2_lock_res_init_once(res);
+        ocfs2_build_lock_name(OCFS2_LOCK_TYPE_NFS_SYNC, 0, 0, res->l_name);
+        ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_NFS_SYNC,
+                                   &ocfs2_nfs_sync_lops, osb);
+}
+
 void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
                               struct ocfs2_file_private *fp)
 {
@@ -2417,6 +2432,34 @@ void ocfs2_rename_unlock(struct ocfs2_super *osb)
                 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
 }
 
+int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex)
+{
+        int status;
+        struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
+
+        if (ocfs2_is_hard_readonly(osb))
+                return -EROFS;
+
+        if (ocfs2_mount_local(osb))
+                return 0;
+
+        status = ocfs2_cluster_lock(osb, lockres, ex ? LKM_EXMODE : LKM_PRMODE,
+                                    0, 0);
+        if (status < 0)
+                mlog(ML_ERROR, "lock on nfs sync lock failed %d\n", status);
+
+        return status;
+}
+
+void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex)
+{
+        struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
+
+        if (!ocfs2_mount_local(osb))
+                ocfs2_cluster_unlock(osb, lockres,
+                                     ex ? LKM_EXMODE : LKM_PRMODE);
+}
+
 int ocfs2_dentry_lock(struct dentry *dentry, int ex)
 {
         int ret;
@@ -2798,6 +2841,7 @@ int ocfs2_dlm_init(struct ocfs2_super *osb)
 local:
         ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
         ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
+        ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb);
 
         osb->cconn = conn;
 
@@ -2833,6 +2877,7 @@ void ocfs2_dlm_shutdown(struct ocfs2_super *osb,
 
         ocfs2_lock_res_free(&osb->osb_super_lockres);
         ocfs2_lock_res_free(&osb->osb_rename_lockres);
+        ocfs2_lock_res_free(&osb->osb_nfs_sync_lockres);
 
         ocfs2_cluster_disconnect(osb->cconn, hangup_pending);
         osb->cconn = NULL;
@@ -3015,6 +3060,7 @@ static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
 {
         ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres);
         ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres);
+        ocfs2_simple_drop_lockres(osb, &osb->osb_nfs_sync_lockres);
 }
 
 int ocfs2_drop_inode_locks(struct inode *inode)
diff --git a/fs/ocfs2/dlmglue.h b/fs/ocfs2/dlmglue.h
index 3f8d9986b8e..e1fd5721cd7 100644
--- a/fs/ocfs2/dlmglue.h
+++ b/fs/ocfs2/dlmglue.h
@@ -115,6 +115,8 @@ void ocfs2_super_unlock(struct ocfs2_super *osb,
                         int ex);
 int ocfs2_rename_lock(struct ocfs2_super *osb);
 void ocfs2_rename_unlock(struct ocfs2_super *osb);
+int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex);
+void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex);
 int ocfs2_dentry_lock(struct dentry *dentry, int ex);
 void ocfs2_dentry_unlock(struct dentry *dentry, int ex);
 int ocfs2_file_lock(struct file *file, int ex, int trylock);
diff --git a/fs/ocfs2/export.c b/fs/ocfs2/export.c
index 2f27b332d8b..de3da8eb558 100644
--- a/fs/ocfs2/export.c
+++ b/fs/ocfs2/export.c
@@ -31,6 +31,7 @@
 
 #include "ocfs2.h"
 
+#include "alloc.h"
 #include "dir.h"
 #include "dlmglue.h"
 #include "dcache.h"
@@ -38,6 +39,7 @@
 #include "inode.h"
 
 #include "buffer_head_io.h"
+#include "suballoc.h"
 
 struct ocfs2_inode_handle
 {
@@ -49,29 +51,97 @@ static struct dentry *ocfs2_get_dentry(struct super_block *sb,
                 struct ocfs2_inode_handle *handle)
 {
         struct inode *inode;
+        struct ocfs2_super *osb = OCFS2_SB(sb);
+        u64 blkno = handle->ih_blkno;
+        int status, set;
         struct dentry *result;
 
         mlog_entry("(0x%p, 0x%p)\n", sb, handle);
 
-        if (handle->ih_blkno == 0) {
-                mlog_errno(-ESTALE);
-                return ERR_PTR(-ESTALE);
+        if (blkno == 0) {
+                mlog(0, "nfs wants inode with blkno: 0\n");
+                result = ERR_PTR(-ESTALE);
+                goto bail;
+        }
+
+        inode = ocfs2_ilookup(sb, blkno);
+        /*
+         * If the inode exists in memory, we only need to check it's
+         * generation number
+         */
+        if (inode)
+                goto check_gen;
+
+        /*
+         * This will synchronize us against ocfs2_delete_inode() on
+         * all nodes
+         */
+        status = ocfs2_nfs_sync_lock(osb, 1);
+        if (status < 0) {
+                mlog(ML_ERROR, "getting nfs sync lock(EX) failed %d\n", status);
+                goto check_err;
+        }
+
+        status = ocfs2_test_inode_bit(osb, blkno, &set);
+        if (status < 0) {
+                if (status == -EINVAL) {
+                        /*
+                         * The blkno NFS gave us doesn't even show up
+                         * as an inode, we return -ESTALE to be
+                         * nice
+                         */
+                        mlog(0, "test inode bit failed %d\n", status);
+                        status = -ESTALE;
+                } else {
+                        mlog(ML_ERROR, "test inode bit failed %d\n", status);
+                }
+                goto unlock_nfs_sync;
+        }
+
+        /* If the inode allocator bit is clear, this inode must be stale */
+        if (!set) {
+                mlog(0, "inode %llu suballoc bit is clear\n", blkno);
+                status = -ESTALE;
+                goto unlock_nfs_sync;
         }
 
-        inode = ocfs2_iget(OCFS2_SB(sb), handle->ih_blkno, 0, 0);
+        inode = ocfs2_iget(osb, blkno, 0, 0);
 
-        if (IS_ERR(inode))
-                return (void *)inode;
+unlock_nfs_sync:
+        ocfs2_nfs_sync_unlock(osb, 1);
 
+check_err:
+        if (status < 0) {
+                if (status == -ESTALE) {
+                        mlog(0, "stale inode ino: %llu generation: %u\n",
+                             blkno, handle->ih_generation);
+                }
+                result = ERR_PTR(status);
+                goto bail;
+        }
+
+        if (IS_ERR(inode)) {
+                mlog_errno(PTR_ERR(inode));
+                result = (void *)inode;
+                goto bail;
+        }
+
+check_gen:
         if (handle->ih_generation != inode->i_generation) {
                 iput(inode);
-                return ERR_PTR(-ESTALE);
+                mlog(0, "stale inode ino: %llu generation: %u\n", blkno,
+                     handle->ih_generation);
+                result = ERR_PTR(-ESTALE);
+                goto bail;
         }
 
         result = d_obtain_alias(inode);
         if (!IS_ERR(result))
                 result->d_op = &ocfs2_dentry_ops;
+        else
+                mlog_errno(PTR_ERR(result));
 
+bail:
         mlog_exit_ptr(result);
         return result;
 }
diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index 4a88bce3507..10e1fa87396 100644
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -113,6 +113,17 @@ void ocfs2_get_inode_flags(struct ocfs2_inode_info *oi)
                 oi->ip_attr |= OCFS2_DIRSYNC_FL;
 }
 
+struct inode *ocfs2_ilookup(struct super_block *sb, u64 blkno)
+{
+        struct ocfs2_find_inode_args args;
+
+        args.fi_blkno = blkno;
+        args.fi_flags = 0;
+        args.fi_ino = ino_from_blkno(sb, blkno);
+        args.fi_sysfile_type = 0;
+
+        return ilookup5(sb, blkno, ocfs2_find_actor, &args);
+}
 struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 blkno, unsigned flags,
                          int sysfile_type)
 {
@@ -961,6 +972,17 @@ void ocfs2_delete_inode(struct inode *inode)
                 goto bail;
         }
 
+        /*
+         * Synchronize us against ocfs2_get_dentry. We take this in
+         * shared mode so that all nodes can still concurrently
+         * process deletes.
+         */
+        status = ocfs2_nfs_sync_lock(OCFS2_SB(inode->i_sb), 0);
+        if (status < 0) {
+                mlog(ML_ERROR, "getting nfs sync lock(PR) failed %d\n", status);
+                ocfs2_cleanup_delete_inode(inode, 0);
+                goto bail_unblock;
+        }
         /* Lock down the inode. This gives us an up to date view of
          * it's metadata (for verification), and allows us to
          * serialize delete_inode on multiple nodes.
@@ -974,7 +996,7 @@ void ocfs2_delete_inode(struct inode *inode)
                 if (status != -ENOENT)
                         mlog_errno(status);
                 ocfs2_cleanup_delete_inode(inode, 0);
-                goto bail_unblock;
+                goto bail_unlock_nfs_sync;
         }
 
         /* Query the cluster. This will be the final decision made
@@ -1017,6 +1039,10 @@ void ocfs2_delete_inode(struct inode *inode)
 bail_unlock_inode:
         ocfs2_inode_unlock(inode, 1);
         brelse(di_bh);
+
+bail_unlock_nfs_sync:
+        ocfs2_nfs_sync_unlock(OCFS2_SB(inode->i_sb), 0);
+
 bail_unblock:
         status = sigprocmask(SIG_SETMASK, &oldset, NULL);
         if (status < 0)
diff --git a/fs/ocfs2/inode.h b/fs/ocfs2/inode.h
index e1978acbf65..ea71525aad4 100644
--- a/fs/ocfs2/inode.h
+++ b/fs/ocfs2/inode.h
@@ -128,6 +128,7 @@ void ocfs2_drop_inode(struct inode *inode);
 /* Flags for ocfs2_iget() */
 #define OCFS2_FI_FLAG_SYSFILE           0x1
 #define OCFS2_FI_FLAG_ORPHAN_RECOVERY   0x2
+struct inode *ocfs2_ilookup(struct super_block *sb, u64 feoff);
 struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 feoff, unsigned flags,
                          int sysfile_type);
 int ocfs2_inode_init_private(struct inode *inode);
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index b65d19c9756..558bd2709e0 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -300,6 +300,7 @@ struct ocfs2_super
         struct ocfs2_cluster_connection *cconn;
         struct ocfs2_lock_res osb_super_lockres;
         struct ocfs2_lock_res osb_rename_lockres;
+        struct ocfs2_lock_res osb_nfs_sync_lockres;
         struct ocfs2_dlm_debug *osb_dlm_debug;
 
         struct dentry *osb_debug_root;
diff --git a/fs/ocfs2/ocfs2_lockid.h b/fs/ocfs2/ocfs2_lockid.h
index eb6f50c9cec..a53ce87481b 100644
--- a/fs/ocfs2/ocfs2_lockid.h
+++ b/fs/ocfs2/ocfs2_lockid.h
@@ -47,6 +47,7 @@ enum ocfs2_lock_type {
         OCFS2_LOCK_TYPE_OPEN,
         OCFS2_LOCK_TYPE_FLOCK,
         OCFS2_LOCK_TYPE_QINFO,
+        OCFS2_LOCK_TYPE_NFS_SYNC,
         OCFS2_NUM_LOCK_TYPES
 };
 
@@ -81,6 +82,9 @@ static inline char ocfs2_lock_type_char(enum ocfs2_lock_type type)
                 case OCFS2_LOCK_TYPE_QINFO:
                         c = 'Q';
                         break;
+                case OCFS2_LOCK_TYPE_NFS_SYNC:
+                        c = 'Y';
+                        break;
                 default:
                         c = '\0';
         }
diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 4c1399cc03f..b4ca5911caa 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -2185,3 +2185,162 @@ out:
 
         return ret;
 }
+
+/*
+ * Read the inode specified by blkno to get suballoc_slot and
+ * suballoc_bit.
+ */
+static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
+                                       u16 *suballoc_slot, u16 *suballoc_bit)
+{
+        int status;
+        struct buffer_head *inode_bh = NULL;
+        struct ocfs2_dinode *inode_fe;
+
+        mlog_entry("blkno: %llu\n", blkno);
+
+        /* dirty read disk */
+        status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
+        if (status < 0) {
+                mlog(ML_ERROR, "read block %llu failed %d\n", blkno, status);
+                goto bail;
+        }
+
+        inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
+        if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
+                mlog(ML_ERROR, "invalid inode %llu requested\n", blkno);
+                status = -EINVAL;
+                goto bail;
+        }
+
+        if (le16_to_cpu(inode_fe->i_suballoc_slot) != OCFS2_INVALID_SLOT &&
+            (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
+                mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
+                     blkno, (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
+                status = -EINVAL;
+                goto bail;
+        }
+
+        if (suballoc_slot)
+                *suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
+        if (suballoc_bit)
+                *suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
+
+bail:
+        brelse(inode_bh);
+
+        mlog_exit(status);
+        return status;
+}
+
+/*
+ * test whether bit is SET in allocator bitmap or not.  on success, 0
+ * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
+ * is returned and *res is meaningless.  Call this after you have
+ * cluster locked against suballoc, or you may get a result based on
+ * non-up2date contents
+ */
+static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
+                                   struct inode *suballoc,
+                                   struct buffer_head *alloc_bh, u64 blkno,
+                                   u16 bit, int *res)
+{
+        struct ocfs2_dinode *alloc_fe;
+        struct ocfs2_group_desc *group;
+        struct buffer_head *group_bh = NULL;
+        u64 bg_blkno;
+        int status;
+
+        mlog_entry("blkno: %llu bit: %u\n", blkno, (unsigned int)bit);
+
+        alloc_fe = (struct ocfs2_dinode *)alloc_bh->b_data;
+        if ((bit + 1) > ocfs2_bits_per_group(&alloc_fe->id2.i_chain)) {
+                mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
+                     (unsigned int)bit,
+                     ocfs2_bits_per_group(&alloc_fe->id2.i_chain));
+                status = -EINVAL;
+                goto bail;
+        }
+
+        bg_blkno = ocfs2_which_suballoc_group(blkno, bit);
+        status = ocfs2_read_group_descriptor(suballoc, alloc_fe, bg_blkno,
+                                             &group_bh);
+        if (status < 0) {
+                mlog(ML_ERROR, "read group %llu failed %d\n", bg_blkno, status);
+                goto bail;
+        }
+
+        group = (struct ocfs2_group_desc *) group_bh->b_data;
+        *res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
+
+bail:
+        brelse(group_bh);
+
+        mlog_exit(status);
+        return status;
+}
+
+/*
+ * Test if the bit representing this inode (blkno) is set in the
+ * suballocator.
+ *
+ * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
+ *
+ * In the event of failure, a negative value is returned and *res is
+ * meaningless.
+ *
+ * Callers must make sure to hold nfs_sync_lock to prevent
+ * ocfs2_delete_inode() on another node from accessing the same
+ * suballocator concurrently.
+ */
+int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
+{
+        int status;
+        u16 suballoc_bit = 0, suballoc_slot = 0;
+        struct inode *inode_alloc_inode;
+        struct buffer_head *alloc_bh = NULL;
+
+        mlog_entry("blkno: %llu", blkno);
+
+        status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
+                                             &suballoc_bit);
+        if (status < 0) {
+                mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
+                goto bail;
+        }
+
+        inode_alloc_inode =
+                ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
+                                            suballoc_slot);
+        if (!inode_alloc_inode) {
+                /* the error code could be inaccurate, but we are not able to
+                 * get the correct one. */
+                status = -EINVAL;
+                mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
+                     (u32)suballoc_slot);
+                goto bail;
+        }
+
+        mutex_lock(&inode_alloc_inode->i_mutex);
+        status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
+        if (status < 0) {
+                mutex_unlock(&inode_alloc_inode->i_mutex);
+                mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
+                     (u32)suballoc_slot, status);
+                goto bail;
+        }
+
+        status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
+                                         blkno, suballoc_bit, res);
+        if (status < 0)
+                mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
+
+        ocfs2_inode_unlock(inode_alloc_inode, 0);
+        mutex_unlock(&inode_alloc_inode->i_mutex);
+
+        iput(inode_alloc_inode);
+        brelse(alloc_bh);
+bail:
+        mlog_exit(status);
+        return status;
+}
diff --git a/fs/ocfs2/suballoc.h b/fs/ocfs2/suballoc.h
index ea85a4c8b4b..8c9a78a4316 100644
--- a/fs/ocfs2/suballoc.h
+++ b/fs/ocfs2/suballoc.h
@@ -188,4 +188,6 @@ int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_extent_tree *et,
                           u32 clusters_to_add, u32 extents_to_split,
                           struct ocfs2_alloc_context **data_ac,
                           struct ocfs2_alloc_context **meta_ac);
+
+int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res);
 #endif /* _CHAINALLOC_H_ */