[lvm-devel] master - thin: reworked thin feature detection
Zdenek Kabelac
zkabelac at fedoraproject.org
Mon Dec 3 10:57:58 UTC 2012
Gitweb: http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=5ec20e267fdc627e3bf50679b748c937fe3d79fb
Commit: 5ec20e267fdc627e3bf50679b748c937fe3d79fb
Parent: 99018b37ee9e916662ebd482ac8fe0f36bbd7ac8
Author: Zdenek Kabelac <zkabelac at redhat.com>
AuthorDate: Mon Dec 3 11:52:04 2012 +0100
Committer: Zdenek Kabelac <zkabelac at redhat.com>
CommitterDate: Mon Dec 3 11:57:40 2012 +0100
thin: reworked thin feature detection
Rework thin feature detection to support runtime
section to allow to disable them selectively.
New lvm.conf option is born: global/thin_disabled_features
---
WHATS_NEW | 1 +
doc/example.conf.in | 10 ++++++
lib/thin/thin.c | 91 ++++++++++++++++++++++++++++++++++++--------------
3 files changed, 76 insertions(+), 26 deletions(-)
diff --git a/WHATS_NEW b/WHATS_NEW
index ceb2295..cff005d 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
Version 2.02.99 -
===================================
+ Add lvm.conf option global/thin_disabled_features.
Add lvconvert support to swap thin pool metadata volume.
Implement internal function detach_pool_metadata_lv().
Fix lvm2app to return all property sizes in bytes.
diff --git a/doc/example.conf.in b/doc/example.conf.in
index 1a3ee1b..872d6ef 100644
--- a/doc/example.conf.in
+++ b/doc/example.conf.in
@@ -524,6 +524,16 @@ global {
# String with options passed with thin_check command. By default,
# option '-q' is for quiet output.
thin_check_options = [ "-q" ]
+
+ # If set, given features are not used by thin driver.
+ # This can be helpful not just for testing, but i.e. allows to avoid
+ # using problematic implementation of some thin feature.
+ # Features:
+ # block_size
+ # discards
+ # discards_non_power_2
+ #
+ # thin_disabled_features = [ "discards", "block_size" ]
}
activation {
diff --git a/lib/thin/thin.c b/lib/thin/thin.c
index f6ac437..18b819b 100644
--- a/lib/thin/thin.c
+++ b/lib/thin/thin.c
@@ -37,6 +37,24 @@
log_error(t " segment %s of logical volume %s.", ## p, \
dm_config_parent_name(sn), seg->lv->name), 0;
+/* List of features with their kernel target version */
+static const struct feature {
+ uint32_t maj;
+ uint32_t min;
+ unsigned thin_feature;
+ const char *feature;
+} _features[] = {
+ { 1, 1, THIN_FEATURE_DISCARDS, "discards" },
+ { 1, 1, THIN_FEATURE_EXTERNAL_ORIGIN, "external_origin" },
+ { 1, 4, THIN_FEATURE_BLOCK_SIZE, "block_size" },
+ { 1, 5, THIN_FEATURE_DISCARDS_NON_POWER_2, "discards_non_power_2" },
+};
+
+static const char _lvmconf[] = "global/thin_disabled_features";
+/* TODO: using static field heer, maybe should be part of segment_type */
+static unsigned _feature_mask;
+static int _log_feature_mask;
+
static int _thin_target_present(struct cmd_context *cmd,
const struct lv_segment *seg,
unsigned *attributes);
@@ -541,8 +559,9 @@ static int _thin_target_present(struct cmd_context *cmd,
{
static int _checked = 0;
static int _present = 0;
- static int _attrs = 0;
+ static unsigned _attrs = 0;
uint32_t maj, min, patchlevel;
+ unsigned i;
if (!_checked) {
_present = target_present(cmd, THIN_MODULE, 1);
@@ -552,35 +571,27 @@ static int _thin_target_present(struct cmd_context *cmd,
return 0;
}
- if (maj >=1 && min >= 1)
- _attrs |= THIN_FEATURE_DISCARDS;
- else
- /* FIXME Log this as WARNING later only if the user asked for the feature to be used but it's not present */
- log_debug("Target " THIN_MODULE " does not support discards.");
-
- if (maj >=1 && min >= 1)
- _attrs |= THIN_FEATURE_EXTERNAL_ORIGIN;
- else
- /* FIXME Log this as WARNING later only if the user asked for the feature to be used but it's not present */
- log_debug("Target " THIN_MODULE " does not support external origins.");
-
- if (maj >=1 && min >= 4)
- _attrs |= THIN_FEATURE_BLOCK_SIZE;
- else
- /* FIXME Log this as WARNING later only if the user asked for the feature to be used but it's not present */
- log_debug("Target " THIN_MODULE " does not support non power of 2 block sizes.");
-
- if (maj >=1 && min >= 5)
- _attrs |= THIN_FEATURE_DISCARDS_NON_POWER_2;
- else
- /* FIXME Log this as WARNING later only if the user asked for the feature to be used but it's not present */
- log_debug("Target " THIN_MODULE " does not support discards for non power of 2 block sizes.");
+ for (i = 0; i < sizeof(_features)/sizeof(*_features); i++)
+ if (maj >= _features[i].maj && min >= _features[i].min)
+ _attrs |= _features[i].thin_feature;
+ else
+ log_very_verbose("Target " THIN_MODULE " does not support %s.",
+ _features[i].feature);
_checked = 1;
}
- if (attributes)
- *attributes = _attrs;
+ if (attributes) {
+ if (_log_feature_mask) {
+ for (i = 0; i < sizeof(_features)/sizeof(*_features); i++)
+ if ((_attrs & _features[i].thin_feature) &&
+ !(_feature_mask & _features[i].thin_feature))
+ log_very_verbose("Target "THIN_MODULE " %s support disabled by %s",
+ _features[i].feature, _lvmconf);
+ _log_feature_mask = 0; /* log just once */
+ }
+ *attributes = _attrs & _feature_mask;
+ }
return _present;
}
@@ -653,7 +664,11 @@ int init_multiple_segtypes(struct cmd_context *cmd, struct segtype_library *segl
};
struct segment_type *segtype;
+ const struct dm_config_node *cn;
+ const struct dm_config_value *cv;
+ const char *str;
unsigned i;
+ unsigned mask = 0;
for (i = 0; i < sizeof(reg_segtypes)/sizeof(reg_segtypes[0]); ++i) {
segtype = dm_zalloc(sizeof(*segtype));
@@ -682,5 +697,29 @@ int init_multiple_segtypes(struct cmd_context *cmd, struct segtype_library *segl
log_very_verbose("Initialised segtype: %s", segtype->name);
}
+ /* Support runtime lvm.conf changes */
+ if ((cn = find_config_tree_node(cmd, _lvmconf))) {
+ for (cv = cn->v; cv; cv = cv->next) {
+ if (cv->type != DM_CFG_STRING) {
+ log_error("Ignoring invalid string in config file %s.",
+ _lvmconf);
+ continue;
+ }
+ str = cv->v.str;
+ if (!*str) {
+ log_error("Ignoring empty string in config file %s.",
+ _lvmconf);
+ continue;
+ }
+ for (i = 0; i < sizeof(_features)/sizeof(*_features); i++)
+ if (strcasecmp(str, _features[i].feature) == 0)
+ mask |= _features[i].thin_feature;
+ }
+ _log_feature_mask = (mask != 0);
+ }
+
+ /* Store as 'and' mask in static field */
+ _feature_mask = ~mask;
+
return 1;
}
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