gfapi: provide stable st_dev in stat structure

Samba depends on st_dev being unique and stable for different
filesystems (it uses st_dev+st_ino as key to store metadata of
a file).

Change-Id: Ia022fabadfb5ef3fc9724c1b1ca86f1a20f98af9
BUG: 953694
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/5045
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>

3 files changed, 16 insertions, 4 deletions

diff --git a/api/src/glfs-fops.c b/api/src/glfs-fops.c
index 0bea82a04cb..dadaf4b4d10 100644
--- a/api/src/glfs-fops.c
+++ b/api/src/glfs-fops.c
@@ -52,6 +52,14 @@ glfs_loc_link (loc_t *loc, struct iatt *iatt)
 }
 
 
+static void
+glfs_iatt_to_stat (struct glfs *fs, struct iatt *iatt, struct stat *stat)
+{
+	iatt_to_stat (iatt, stat);
+	stat->st_dev = fs->dev_id;
+}
+
+
 static int
 glfs_loc_unlink (loc_t *loc)
 {
@@ -172,7 +180,7 @@ retry:
 	ESTALE_RETRY (ret, errno, reval, &loc, retry);
 
 	if (ret == 0 && stat)
-		iatt_to_stat (&iatt, stat);
+		glfs_iatt_to_stat (fs, &iatt, stat);
 out:
 	loc_wipe (&loc);
 
@@ -203,7 +211,7 @@ retry:
 	ESTALE_RETRY (ret, errno, reval, &loc, retry);
 
 	if (ret == 0 && stat)
-		iatt_to_stat (&iatt, stat);
+		glfs_iatt_to_stat (fs, &iatt, stat);
 out:
 	loc_wipe (&loc);
 
@@ -230,7 +238,7 @@ glfs_fstat (struct glfs_fd *glfd, struct stat *stat)
 	ret = syncop_fstat (subvol, glfd->fd, &iatt);
 
 	if (ret == 0 && stat)
-		iatt_to_stat (&iatt, stat);
+		glfs_iatt_to_stat (glfd->fs, &iatt, stat);
 out:
 	return ret;
 }
@@ -1705,7 +1713,7 @@ glfs_readdirplus_r (struct glfs_fd *glfd, struct stat *stat, struct dirent *buf,
 	if (entry) {
 		gf_dirent_to_dirent (entry, buf);
 		if (stat)
-			iatt_to_stat (&entry->d_stat, stat);
+			glfs_iatt_to_stat (glfd->fs, &entry->d_stat, stat);
 	}
 out:
 	return ret;
diff --git a/api/src/glfs-internal.h b/api/src/glfs-internal.h
index 7c622637da0..d658ce2ae19 100644
--- a/api/src/glfs-internal.h
+++ b/api/src/glfs-internal.h
@@ -38,6 +38,8 @@ struct glfs {
 	ssize_t             oldvollen;
 
 	inode_t            *cwd;
+
+	uint32_t            dev_id; /* Used to fill st_dev in struct stat */
 };
 
 struct glfs_fd {
diff --git a/api/src/glfs.c b/api/src/glfs.c
index ac55628bd55..3962a39da44 100644
--- a/api/src/glfs.c
+++ b/api/src/glfs.c
@@ -52,6 +52,7 @@
 
 #include "glfs.h"
 #include "glfs-internal.h"
+#include "hashfn.h"
 
 
 static gf_boolean_t
@@ -577,6 +578,7 @@ glfs_init_common (struct glfs *fs)
 	if (ret)
 		return ret;
 
+	fs->dev_id = gf_dm_hashfn (fs->volname, strlen (fs->volname));
 	return ret;
 }