Attachment 15290 Details for Bug 13972 – patch for master

[patch] patch for master

patch-fix-bug-13972.patch (text/plain), 6.55 KB, created by Michael Adam on 2019-07-07 12:04:47 UTC

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Creator: Michael Adam

Created: 2019-07-07 12:04:47 UTC

Size: 6.55 KB

patch

obsolete

>From 52ef5a39f70ad191b752eb9d5b8d0d26108fe19d Mon Sep 17 00:00:00 2001
>From: Michael Adam <obnox@samba.org>
>Date: Sat, 18 May 2019 11:28:54 +0200
>Subject: [PATCH] vfs:glusterfs_fuse: ensure fileids are constant across nodes
>
>Instead of adding a new gluster-specific mode to the fileid module,
>this patches provides a fileid algorithm as part of the glusterfs_fuse
>vfs module. This can not be configured further, simply adding the
>glusterfs_fuse vfs module to the vfs objects configuration will enable
>the new fileid mode.
>
>BUG: https://bugzilla.samba.org/show_bug.cgi?id=13972
>
>Signed-off-by: Michael Adam <obnox@samba.org>
>Signed-off-by: Guenther Deschner <gd@samba.org>
>---
> docs-xml/manpages/vfs_glusterfs_fuse.8.xml |   8 +
> source3/modules/vfs_glusterfs_fuse.c       | 193 ++++++++++++++++++++-
> 2 files changed, 200 insertions(+), 1 deletion(-)
>
>diff --git a/docs-xml/manpages/vfs_glusterfs_fuse.8.xml b/docs-xml/manpages/vfs_glusterfs_fuse.8.xml
>index b9f7f42c6f2..f2aa624353e 100644
>--- a/docs-xml/manpages/vfs_glusterfs_fuse.8.xml
>+++ b/docs-xml/manpages/vfs_glusterfs_fuse.8.xml
>@@ -48,6 +48,14 @@
> 		case of an exisiting filename.
> 	</para>
> 
>+	<para>
>+		Furthermore, this module implements a substitute file-id
>+		mechanism. The default file-id mechanism is not working
>+		correctly for gluster fuse mount re-exports, so in order to
>+		avoid data loss, users exporting gluster fuse mounts with
>+		Samba should enable this module.
>+	</para>
>+
> 	<para>
> 		This module can be combined with other modules, but it
> 		should be the last module in the <command>vfs objects</command>
>diff --git a/source3/modules/vfs_glusterfs_fuse.c b/source3/modules/vfs_glusterfs_fuse.c
>index 51515aa0df4..c621f9abf8e 100644
>--- a/source3/modules/vfs_glusterfs_fuse.c
>+++ b/source3/modules/vfs_glusterfs_fuse.c
>@@ -59,10 +59,201 @@ static int vfs_gluster_fuse_get_real_filename(struct vfs_handle_struct *handle,
> 	return 0;
> }
> 
>+struct device_mapping_entry {
>+	SMB_DEV_T device;       /* the local device, for reference */
>+	uint64_t mapped_device; /* the mapped device */
>+};
>+
>+struct vfs_glusterfs_fuse_handle_data {
>+	unsigned num_mapped_devices;
>+	struct device_mapping_entry *mapped_devices;
>+};
>+
>+/* a 64 bit hash, based on the one in tdb, copied from vfs_fileied */
>+static uint64_t vfs_glusterfs_fuse_uint64_hash(const uint8_t *s, size_t len)
>+{
>+	uint64_t value; /* Used to compute the hash value.  */
>+	uint32_t i;     /* Used to cycle through random values. */
>+
>+	/* Set the initial value from the key size. */
>+	for (value = 0x238F13AFLL * len, i=0; i < len; i++)
>+		value = (value + (((uint64_t)s[i]) << (i*5 % 24)));
>+
>+	return (1103515243LL * value + 12345LL);
>+}
>+
>+static void vfs_glusterfs_fuse_load_devices(
>+		struct vfs_glusterfs_fuse_handle_data *data)
>+{
>+	FILE *f;
>+	struct mntent *m;
>+
>+	data->num_mapped_devices = 0;
>+	TALLOC_FREE(data->mapped_devices);
>+
>+	f = setmntent("/etc/mtab", "r");
>+	if (!f) {
>+		return;
>+	}
>+
>+	while ((m = getmntent(f))) {
>+		struct stat st;
>+		char *p;
>+		uint64_t mapped_device;
>+
>+		if (stat(m->mnt_dir, &st) != 0) {
>+			/* TODO: log? */
>+			continue;
>+		}
>+
>+		/* strip the host part off of the fsname */
>+		p = strrchr(m->mnt_fsname, ':');
>+		if (p == NULL) {
>+			p = m->mnt_fsname;
>+		} else {
>+			/* TODO: consider the case of '' ? */
>+			p++;
>+		}
>+
>+		mapped_device = vfs_glusterfs_fuse_uint64_hash(
>+						(const uint8_t *)p,
>+						strlen(p));
>+
>+		data->mapped_devices = talloc_realloc(data,
>+						data->mapped_devices,
>+						struct device_mapping_entry,
>+						data->num_mapped_devices + 1);
>+		if (data->mapped_devices == NULL) {
>+			goto nomem;
>+		}
>+
>+		data->mapped_devices[data->num_mapped_devices].device =
>+								st.st_dev;
>+		data->mapped_devices[data->num_mapped_devices].mapped_device =
>+								mapped_device;
>+
>+		data->num_mapped_devices++;
>+	}
>+
>+	endmntent(f);
>+	return;
>+
>+nomem:
>+	data->num_mapped_devices = 0;
>+	TALLOC_FREE(data->mapped_devices);
>+
>+	endmntent(f);
>+	return;
>+}
>+
>+static int vfs_glusterfs_fuse_map_device_cached(
>+				struct vfs_glusterfs_fuse_handle_data *data,
>+				SMB_DEV_T device,
>+				uint64_t *mapped_device)
>+{
>+	unsigned i;
>+
>+	for (i = 0; i < data->num_mapped_devices; i++) {
>+		if (data->mapped_devices[i].device == device) {
>+			*mapped_device = data->mapped_devices[i].mapped_device;
>+			return 0;
>+		}
>+	}
>+
>+	return -1;
>+}
>+
>+static int vfs_glusterfs_fuse_map_device(
>+				struct vfs_glusterfs_fuse_handle_data *data,
>+				SMB_DEV_T device,
>+				uint64_t *mapped_device)
>+{
>+	int ret;
>+
>+	ret = vfs_glusterfs_fuse_map_device_cached(data, device, mapped_device);
>+	if (ret == 0) {
>+		return 0;
>+	}
>+
>+	vfs_glusterfs_fuse_load_devices(data);
>+
>+	ret = vfs_glusterfs_fuse_map_device_cached(data, device, mapped_device);
>+
>+	return ret;
>+}
>+
>+static struct file_id vfs_glusterfs_fuse_file_id_create(
>+			struct vfs_handle_struct *handle,
>+			const SMB_STRUCT_STAT *sbuf)
>+{
>+	struct vfs_glusterfs_fuse_handle_data *data;
>+	struct file_id id;
>+	uint64_t mapped_device;
>+	int ret;
>+
>+	ZERO_STRUCT(id);
>+
>+	id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, sbuf);
>+
>+	SMB_VFS_HANDLE_GET_DATA(handle, data,
>+				struct vfs_glusterfs_fuse_handle_data,
>+				return id);
>+
>+	ret = vfs_glusterfs_fuse_map_device(data, sbuf->st_ex_dev,
>+					    &mapped_device);
>+	if (ret == 0) {
>+		id.devid = mapped_device;
>+	} else {
>+		DBG_WARNING("Failed to map device [%jx], falling back to "
>+			    "standard file_id [%jx]",
>+			    (uintmax_t)sbuf->st_ex_dev,
>+			    (uintmax_t)id.devid);
>+	}
>+
>+	DBG_DEBUG("Returning dev [%jx] inode [%jx]\n",
>+		  (uintmax_t)id.devid, (uintmax_t)id.inode);
>+
>+	return id;
>+}
>+
>+static int vfs_glusterfs_fuse_connect(struct vfs_handle_struct *handle,
>+				      const char *service, const char *user)
>+{
>+	struct vfs_glusterfs_fuse_handle_data *data;
>+	int ret = SMB_VFS_NEXT_CONNECT(handle, service, user);
>+
>+	if (ret < 0) {
>+		return ret;
>+	}
>+
>+	data = talloc_zero(handle->conn, struct vfs_glusterfs_fuse_handle_data);
>+	if (data == NULL) {
>+		DBG_ERR("talloc_zero() failed.\n");
>+		SMB_VFS_NEXT_DISCONNECT(handle);
>+		return -1;
>+	}
>+
>+	/*
>+	 * Fill the cache in the tree connect, so that the first file/dir access
>+	 * has chances of being fast...
>+	 */
>+	vfs_glusterfs_fuse_load_devices(data);
>+
>+	SMB_VFS_HANDLE_SET_DATA(handle, data, NULL,
>+				struct vfs_glusterfs_fuse_handle_data,
>+				return -1);
>+
>+	DBG_DEBUG("vfs_glusterfs_fuse_connect(): connected to service[%s]\n",
>+		  service);
>+
>+	return 0;
>+}
>+
> struct vfs_fn_pointers glusterfs_fuse_fns = {
> 
>-	/* File Operations */
>+	.connect_fn = vfs_glusterfs_fuse_connect,
> 	.get_real_filename_fn = vfs_gluster_fuse_get_real_filename,
>+	.file_id_create_fn = vfs_glusterfs_fuse_file_id_create,
> };
> 
> static_decl_vfs;
>-- 
>2.21.0
>

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Attachments on bug 13972: 15290 | 15365 | 15366 | 15419 | 15428