Bitrot Stub

Bitrot stub implements object versioning required for identifying
signature freshness. More details about versioning is explained
as a part of the "bitrot feature documentation" patch.

Change-Id: I2ad70d9eb109ba4a12148ab8d81336afda529ad9
BUG: 1170075
Signed-off-by: Venky Shankar <vshankar@redhat.com>
Reviewed-on: http://review.gluster.org/9709
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

3 files changed, 96 insertions, 0 deletions

diff --git a/xlators/storage/posix/src/posix-helpers.c b/xlators/storage/posix/src/posix-helpers.c
index edbf0241f26..4a062970f7d 100644
--- a/xlators/storage/posix/src/posix-helpers.c
+++ b/xlators/storage/posix/src/posix-helpers.c
@@ -1855,3 +1855,73 @@ posix_fsyncer (void *d)
                 }
         }
 }
+
+/**
+ * fetch on-disk ongoing version and object signature extended
+ * attribute.
+ */
+int32_t
+posix_get_objectsignature (char *real_path, dict_t *xattr)
+{
+        int32_t  op_ret    = 0;
+        char    *memptr    = NULL;
+        ssize_t  xattrsize = 0;
+        ssize_t  allocsize = 0;
+
+        op_ret = -EINVAL;
+        xattrsize = sys_lgetxattr (real_path,
+                                   BITROT_CURRENT_VERSION_KEY, NULL, 0);
+        if (xattrsize == -1)
+                goto error_return;
+        allocsize += xattrsize;
+
+        xattrsize = sys_lgetxattr (real_path,
+                                   BITROT_SIGNING_VERSION_KEY, NULL, 0);
+        if (xattrsize == -1)
+                goto error_return;
+        allocsize += xattrsize;
+
+        op_ret = -ENOMEM;
+        /* bulk alloc */
+        memptr = GF_CALLOC (allocsize + 2, sizeof (char), gf_posix_mt_char);
+        if (!memptr)
+                goto error_return;
+
+        op_ret = sys_lgetxattr (real_path, BITROT_CURRENT_VERSION_KEY,
+                                memptr, allocsize - xattrsize);
+        if (op_ret == -1) {
+                op_ret = -errno;
+                goto dealloc_mem;
+        }
+
+        xattrsize = op_ret; /* save for correct _in_ memory pointing */
+
+        op_ret = sys_lgetxattr (real_path, BITROT_SIGNING_VERSION_KEY,
+                                (memptr + op_ret + 1), allocsize - op_ret);
+        if (op_ret == -1) {
+                op_ret = -errno;
+                goto dealloc_mem;
+        }
+
+        /* this is a dynamic set */
+        op_ret = dict_set_dynptr (xattr, BITROT_CURRENT_VERSION_KEY,
+                                  memptr, allocsize);
+        if (op_ret < 0)
+                goto dealloc_mem;
+
+        /* rest all should be static */
+        op_ret = dict_set_static_ptr (xattr, BITROT_SIGNING_VERSION_KEY,
+                                      memptr + xattrsize + 1);
+        if (op_ret < 0)
+                goto delkey;
+
+        return allocsize;
+
+ delkey:
+        dict_del (xattr, BITROT_CURRENT_VERSION_KEY);
+ dealloc_mem:
+        GF_FREE (memptr);
+ error_return:
+        return op_ret;
+
+}
diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index 8001f238614..ae08adcc8e0 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -3882,6 +3882,18 @@ posix_getxattr (call_frame_t *frame, xlator_t *this,
                 goto done;
         }
 
+        if (loc->inode && name
+             && (strncmp (name, GLUSTERFS_GET_OBJECT_SIGNATURE,
+                          strlen (GLUSTERFS_GET_OBJECT_SIGNATURE)) == 0)) {
+                op_ret = posix_get_objectsignature (real_path, dict);
+                if (op_ret < 0) {
+                        op_errno = -op_ret;
+                        op_ret = -1;
+                }
+
+                goto done;
+        }
+
         if (name) {
                 strcpy (keybuffer, name);
                 char *key = keybuffer;
@@ -4316,6 +4328,17 @@ posix_fsetxattr (call_frame_t *frame, xlator_t *this,
                 op_ret = -1;
         }
 
+        if (!ret && xdata && dict_get (xdata, GLUSTERFS_DURABLE_OP)) {
+                op_ret = fsync (_fd);
+                if (op_ret < 0) {
+                        op_ret = -1;
+                        op_errno = errno;
+                        gf_log (this->name, GF_LOG_WARNING,
+                                "could not satisfy durability request: "
+                                "reason (%s)", strerror (errno));
+                }
+        }
+
 out:
         SET_TO_OLD_FS_ID ();
 
diff --git a/xlators/storage/posix/src/posix.h b/xlators/storage/posix/src/posix.h
index bdb56b1d59d..452248dd794 100644
--- a/xlators/storage/posix/src/posix.h
+++ b/xlators/storage/posix/src/posix.h
@@ -242,4 +242,7 @@ posix_pacl_set (const char *path, const char *key, const char *acl_s);
 int
 posix_pacl_get (const char *path, const char *key, char **acl_s);
 
+int32_t
+posix_get_objectsignature (char *, dict_t *);
+
 #endif /* _POSIX_H */