[lvm-devel] LVM2 ./WHATS_NEW lib/activate/activate.c lib/a ...
zkabelac at sourceware.org
zkabelac at sourceware.org
Fri Feb 4 19:14:44 UTC 2011
CVSROOT: /cvs/lvm2
Module name: LVM2
Changes by: zkabelac at sourceware.org 2011-02-04 19:14:41
Modified files:
. : WHATS_NEW
lib/activate : activate.c fs.c
libdm : libdm-common.c
Log message:
Fix operation node stacking for consecutive dm ops
With the ability to stack many operations in one udev transaction -
in same cases we are adding and removing same device at the same time
(i.e. deactivate followed by activate).
This leads to a problem of checking stacked operations:
i.e. remove /dev/node1 followed by create /dev/node1
If the node creation is handled with udev - there is a problem as
stacked operation gives warning about existing node1 and will try to
remove it - while next operation needs to recreate it.
Current code removes all previous stacked operation if the fs op is
FS_DEL - patch adds similar behavior for FS_ADD - it will try to
remove any 'delete' operation if udev is in use.
For FS_RENAME operation it seems to be more complex. But as we
are always stacking FS_READ_AHEAD after FS_ADD operation -
should be safe to remove all previous operation on the node
when udev is running.
Code does same checking for stacking libdm and liblvm operations.
As a very simple optimization counters were added for each stacked ops
type to avoid unneeded list scans if some operation does not exists in
the list.
Enable skipping of fs_unlock() (udev sync) if only DEL operations are staked.
as we do not use lv_info for already deleted nodes.
Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/WHATS_NEW.diff?cvsroot=lvm2&r1=1.1902&r2=1.1903
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/activate/activate.c.diff?cvsroot=lvm2&r1=1.189&r2=1.190
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/activate/fs.c.diff?cvsroot=lvm2&r1=1.58&r2=1.59
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/libdm/libdm-common.c.diff?cvsroot=lvm2&r1=1.108&r2=1.109
--- LVM2/WHATS_NEW 2011/02/03 16:03:13 1.1902
+++ LVM2/WHATS_NEW 2011/02/04 19:14:39 1.1903
@@ -1,5 +1,6 @@
Version 2.02.83 -
===================================
+ Fix operation node stacking for consecutive dm ops.
Increase hash table size to 1024 lv names and 64 pv uuids.
Remove fs_unlock() from lv_resume path.
Fix wipe size when setting up mda.
--- LVM2/lib/activate/activate.c 2011/02/03 01:58:21 1.189
+++ LVM2/lib/activate/activate.c 2011/02/04 19:14:40 1.190
@@ -469,7 +469,7 @@
if (with_open_count) {
if (locking_is_clustered())
sync_local_dev_names(cmd); /* Wait to have udev in sync */
- else //if (fs_has_non_delete_ops())
+ else if (fs_has_non_delete_ops())
fs_unlock(); /* For non clustered - wait if there are non-delete ops */
}
--- LVM2/lib/activate/fs.c 2011/02/03 01:24:46 1.58
+++ LVM2/lib/activate/fs.c 2011/02/04 19:14:40 1.59
@@ -257,7 +257,8 @@
typedef enum {
FS_ADD,
FS_DEL,
- FS_RENAME
+ FS_RENAME,
+ NUM_FS_OPS
} fs_op_t;
static int _do_fs_op(fs_op_t type, const char *dev_dir, const char *vg_name,
@@ -283,12 +284,18 @@
if (!_mk_link(dev_dir, vg_name, lv_name, dev, check_udev))
stack;
+ default:;
}
return 1;
}
static DM_LIST_INIT(_fs_ops);
+/*
+ * Count number of stacked fs_op_t operations to allow to skip dm_list search.
+ * FIXME: handling of FS_RENAME
+ */
+static int _count_fs_ops[NUM_FS_OPS];
struct fs_op_parms {
struct dm_list list;
@@ -309,15 +316,84 @@
*pos += strlen(*ptr) + 1;
}
+static void _del_fs_op(struct fs_op_parms *fsp)
+{
+ _count_fs_ops[fsp->type]--;
+ dm_list_del(&fsp->list);
+ dm_free(fsp);
+}
+
+/* Check if there is other the type of fs operation stacked */
+static int _other_fs_ops(fs_op_t type)
+{
+ int i;
+
+ for (i = 0; i < NUM_FS_OPS; i++)
+ if (type != i && _count_fs_ops[i])
+ return 1;
+ return 0;
+}
+
+/* Check if udev is supposed to create nodes */
+static int _check_udev(int check_udev)
+{
+ return check_udev && dm_udev_get_sync_support() && dm_udev_get_checking();
+}
+
+/* FIXME: duplication of the code from libdm-common.c */
static int _stack_fs_op(fs_op_t type, const char *dev_dir, const char *vg_name,
const char *lv_name, const char *dev,
const char *old_lv_name, int check_udev)
{
+ struct dm_list *fsph, *fspht;
struct fs_op_parms *fsp;
size_t len = strlen(dev_dir) + strlen(vg_name) + strlen(lv_name) +
strlen(dev) + strlen(old_lv_name) + 5;
char *pos;
+ if ((type == FS_DEL) && _other_fs_ops(type))
+ /*
+ * Ignore any outstanding operations on the fs_op if deleting it.
+ */
+ dm_list_iterate_safe(fsph, fspht, &_fs_ops) {
+ fsp = dm_list_item(fsph, struct fs_op_parms);
+ if (!strcmp(lv_name, fsp->lv_name) &&
+ !strcmp(vg_name, fsp->vg_name)) {
+ _del_fs_op(fsp);
+ if (!_other_fs_ops(type))
+ break; /* no other non DEL ops */
+ }
+ }
+ else if ((type == FS_ADD) && _count_fs_ops[FS_DEL] && _check_udev(check_udev))
+ /*
+ * If udev is running ignore previous DEL operation on added fs_op.
+ * (No other operations for this device then DEL could be staked here).
+ */
+ dm_list_iterate_safe(fsph, fspht, &_fs_ops) {
+ fsp = dm_list_item(fsph, struct fs_op_parms);
+ if ((fsp->type == FS_DEL) &&
+ !strcmp(lv_name, fsp->lv_name) &&
+ !strcmp(vg_name, fsp->vg_name)) {
+ _del_fs_op(fsp);
+ break; /* no other DEL ops */
+ }
+ }
+ else if ((type == FS_RENAME) && _check_udev(check_udev))
+ /*
+ * If udev is running ignore any outstanding operations if renaming it.
+ *
+ * Currently RENAME operation happens through 'suspend -> resume'.
+ * On 'resume' device is added with read_ahead settings, so it
+ * safe to remove any stacked ADD, RENAME, READ_AHEAD operation
+ * There cannot be any DEL operation on the renamed device.
+ */
+ dm_list_iterate_safe(fsph, fspht, &_fs_ops) {
+ fsp = dm_list_item(fsph, struct fs_op_parms);
+ if (!strcmp(old_lv_name, fsp->lv_name) &&
+ !strcmp(vg_name, fsp->vg_name))
+ _del_fs_op(fsp);
+ }
+
if (!(fsp = dm_malloc(sizeof(*fsp) + len))) {
log_error("No space to stack fs operation");
return 0;
@@ -333,6 +409,7 @@
_store_str(&pos, &fsp->dev, dev);
_store_str(&pos, &fsp->old_lv_name, old_lv_name);
+ _count_fs_ops[type]++;
dm_list_add(&_fs_ops, &fsp->list);
return 1;
@@ -347,8 +424,7 @@
fsp = dm_list_item(fsph, struct fs_op_parms);
_do_fs_op(fsp->type, fsp->dev_dir, fsp->vg_name, fsp->lv_name,
fsp->dev, fsp->old_lv_name, fsp->check_udev);
- dm_list_del(&fsp->list);
- dm_free(fsp);
+ _del_fs_op(fsp);
}
}
@@ -423,9 +499,7 @@
_fs_cookie = cookie;
}
-#if 0
int fs_has_non_delete_ops(void)
{
return _other_fs_ops(FS_DEL);
}
-#endif
--- LVM2/libdm/libdm-common.c 2011/02/04 16:08:12 1.108
+++ LVM2/libdm/libdm-common.c 2011/02/04 19:14:40 1.109
@@ -725,7 +725,8 @@
NODE_ADD,
NODE_DEL,
NODE_RENAME,
- NODE_READ_AHEAD
+ NODE_READ_AHEAD,
+ NUM_NODES
} node_op_t;
static int _do_node_op(node_op_t type, const char *dev_name, uint32_t major,
@@ -744,12 +745,14 @@
case NODE_READ_AHEAD:
return _set_dev_node_read_ahead(dev_name, read_ahead,
read_ahead_flags);
+ default:;
}
return 1;
}
static DM_LIST_INIT(_node_ops);
+static int _count_node_ops[NUM_NODES];
struct node_op_parms {
struct dm_list list;
@@ -774,6 +777,31 @@
*pos += strlen(*ptr) + 1;
}
+static void _del_node_op(struct node_op_parms *nop)
+{
+ _count_node_ops[nop->type]--;
+ dm_list_del(&nop->list);
+ dm_free(nop);
+
+}
+
+/* Check if there is other the type of node operation stacked */
+static int _other_node_ops(node_op_t type)
+{
+ int i;
+
+ for (i = 0; i < NUM_NODES; i++)
+ if (type != i && _count_node_ops[i])
+ return 1;
+ return 0;
+}
+
+/* Check if udev is supposed to create nodes */
+static int _check_udev(int check_udev)
+{
+ return check_udev && dm_udev_get_sync_support() && dm_udev_get_checking();
+}
+
static int _stack_node_op(node_op_t type, const char *dev_name, uint32_t major,
uint32_t minor, uid_t uid, gid_t gid, mode_t mode,
const char *old_name, uint32_t read_ahead,
@@ -785,17 +813,47 @@
char *pos;
/*
- * Ignore any outstanding operations on the node if deleting it
+ * Note: check_udev must have valid content
*/
- if (type == NODE_DEL) {
+ if ((type == NODE_DEL) && _other_node_ops(type))
+ /*
+ * Ignore any outstanding operations on the node if deleting it.
+ */
dm_list_iterate_safe(noph, nopht, &_node_ops) {
nop = dm_list_item(noph, struct node_op_parms);
if (!strcmp(dev_name, nop->dev_name)) {
- dm_list_del(&nop->list);
- dm_free(nop);
+ _del_node_op(nop);
+ if (!_other_node_ops(type))
+ break; /* no other non DEL ops */
}
}
- }
+ else if ((type == NODE_ADD) && _count_node_ops[NODE_DEL] && _check_udev(check_udev))
+ /*
+ * If udev is running ignore previous DEL operation on added node.
+ * (No other operations for this device then DEL could be staked here).
+ */
+ dm_list_iterate_safe(noph, nopht, &_node_ops) {
+ nop = dm_list_item(noph, struct node_op_parms);
+ if ((nop->type == NODE_DEL) &&
+ !strcmp(dev_name, nop->dev_name)) {
+ _del_node_op(nop);
+ break; /* no other DEL ops */
+ }
+ }
+ else if ((type == NODE_RENAME) && _check_udev(check_udev))
+ /*
+ * If udev is running ignore any outstanding operations if renaming it.
+ *
+ * Currently RENAME operation happens through 'suspend -> resume'.
+ * On 'resume' device is added with read_ahead settings, so it is
+ * safe to remove any stacked ADD, RENAME, READ_AHEAD operation
+ * There cannot be any DEL operation on the renamed device.
+ */
+ dm_list_iterate_safe(noph, nopht, &_node_ops) {
+ nop = dm_list_item(noph, struct node_op_parms);
+ if (!strcmp(old_name, nop->dev_name))
+ _del_node_op(nop);
+ }
if (!(nop = dm_malloc(sizeof(*nop) + len))) {
log_error("Insufficient memory to stack mknod operation");
@@ -816,6 +874,7 @@
_store_str(&pos, &nop->dev_name, dev_name);
_store_str(&pos, &nop->old_name, old_name);
+ _count_node_ops[type]++;
dm_list_add(&_node_ops, &nop->list);
return 1;
@@ -832,8 +891,7 @@
nop->uid, nop->gid, nop->mode, nop->old_name,
nop->read_ahead, nop->read_ahead_flags,
nop->check_udev);
- dm_list_del(&nop->list);
- dm_free(nop);
+ _del_node_op(nop);
}
}
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