| Message ID | 504A4A17.8060008@inktank.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Reviewed-by: Josh Durgin <josh.durgin@inktank.com> On 09/07/2012 12:25 PM, Alex Elder wrote: > Create a function that encapsulates looking up the name, size and > features related to a given snapshot, which is indicated by its > index in an rbd device's snapshot context array of snapshot ids. > > This interface will be used to hide differences between the format 1 > and format 2 images. > > At the moment this (looking up the name anyway) is slightly less > efficient than what's done currently, but we may be able to optimize > this a bit later on by cacheing the last lookup if it proves to be a > problem. > > Signed-off-by: Alex Elder <elder@inktank.com> > --- > drivers/block/rbd.c | 36 ++++++++++++++++++++++++++++++------ > 1 file changed, 30 insertions(+), 6 deletions(-) > > diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c > index c62d3f4..e6b8fa6 100644 > --- a/drivers/block/rbd.c > +++ b/drivers/block/rbd.c > @@ -2097,6 +2097,25 @@ err: > return ERR_PTR(ret); > } > > +static char *rbd_dev_v1_snap_info(struct rbd_device *rbd_dev, u32 which, > + u64 *snap_size, u64 *snap_features) > +{ > + char *snap_name; > + > + rbd_assert(which < rbd_dev->header.snapc->num_snaps); > + > + *snap_size = rbd_dev->header.snap_sizes[which]; > + *snap_features = 0; /* No features for v1 */ > + > + /* Skip over names until we find the one we are looking for */ > + > + snap_name = rbd_dev->header.snap_names; > + while (which--) > + snap_name += strlen(snap_name) + 1; > + > + return snap_name; > +} > + > /* > * Scan the rbd device's current snapshot list and compare it to the > * newly-received snapshot context. Remove any existing snapshots > @@ -2113,7 +2132,6 @@ static int rbd_dev_snaps_update(struct rbd_device > *rbd_dev) > { > struct ceph_snap_context *snapc = rbd_dev->header.snapc; > const u32 snap_count = snapc->num_snaps; > - char *snap_name = rbd_dev->header.snap_names; > struct list_head *head = &rbd_dev->snaps; > struct list_head *links = head->next; > u32 index = 0; > @@ -2122,6 +2140,9 @@ static int rbd_dev_snaps_update(struct rbd_device > *rbd_dev) > while (index < snap_count || links != head) { > u64 snap_id; > struct rbd_snap *snap; > + char *snap_name; > + u64 snap_size = 0; > + u64 snap_features = 0; > > snap_id = index < snap_count ? snapc->snaps[index] > : CEPH_NOSNAP; > @@ -2148,16 +2169,20 @@ static int rbd_dev_snaps_update(struct > rbd_device *rbd_dev) > continue; > } > > + snap_name = rbd_dev_v1_snap_info(rbd_dev, index, > + &snap_size, &snap_features); > + if (IS_ERR(snap_name)) > + return PTR_ERR(snap_name); > + > dout("entry %u: snap_id = %llu\n", (unsigned int) snap_count, > (unsigned long long) snap_id); > if (!snap || (snap_id != CEPH_NOSNAP && snap->id < snap_id)) { > - struct rbd_image_header *header = &rbd_dev->header; > struct rbd_snap *new_snap; > > /* We haven't seen this snapshot before */ > > new_snap = __rbd_add_snap_dev(rbd_dev, snap_name, > - snap_id, header->snap_sizes[index], 0); > + snap_id, snap_size, snap_features); > if (IS_ERR(new_snap)) { > int err = PTR_ERR(new_snap); > > @@ -2178,9 +2203,9 @@ static int rbd_dev_snaps_update(struct rbd_device > *rbd_dev) > > dout(" already present\n"); > > - rbd_assert(snap->size == > - rbd_dev->header.snap_sizes[index]); > + rbd_assert(snap->size == snap_size); > rbd_assert(!strcmp(snap->name, snap_name)); > + rbd_assert(snap->features == snap_features); > > /* Done with this list entry; advance */ > > @@ -2190,7 +2215,6 @@ static int rbd_dev_snaps_update(struct rbd_device > *rbd_dev) > /* Advance to the next entry in the snapshot context */ > > index++; > - snap_name += strlen(snap_name) + 1; > } > dout("%s: done\n", __func__); > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index c62d3f4..e6b8fa6 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -2097,6 +2097,25 @@ err: return ERR_PTR(ret); } +static char *rbd_dev_v1_snap_info(struct rbd_device *rbd_dev, u32 which, + u64 *snap_size, u64 *snap_features) +{ + char *snap_name; + + rbd_assert(which < rbd_dev->header.snapc->num_snaps); + + *snap_size = rbd_dev->header.snap_sizes[which]; + *snap_features = 0; /* No features for v1 */ + + /* Skip over names until we find the one we are looking for */ + + snap_name = rbd_dev->header.snap_names; + while (which--) + snap_name += strlen(snap_name) + 1; + + return snap_name; +} + /* * Scan the rbd device's current snapshot list and compare it to the * newly-received snapshot context. Remove any existing snapshots @@ -2113,7 +2132,6 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev) { struct ceph_snap_context *snapc = rbd_dev->header.snapc; const u32 snap_count = snapc->num_snaps; - char *snap_name = rbd_dev->header.snap_names; struct list_head *head = &rbd_dev->snaps; struct list_head *links = head->next;
Create a function that encapsulates looking up the name, size and features related to a given snapshot, which is indicated by its index in an rbd device's snapshot context array of snapshot ids. This interface will be used to hide differences between the format 1 and format 2 images. At the moment this (looking up the name anyway) is slightly less efficient than what's done currently, but we may be able to optimize this a bit later on by cacheing the last lookup if it proves to be a problem. Signed-off-by: Alex Elder <elder@inktank.com> --- drivers/block/rbd.c | 36 ++++++++++++++++++++++++++++++------ 1 file changed, 30 insertions(+), 6 deletions(-) u32 index = 0; @@ -2122,6 +2140,9 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev) while (index < snap_count || links != head) { u64 snap_id; struct rbd_snap *snap; + char *snap_name; + u64 snap_size = 0; + u64 snap_features = 0; snap_id = index < snap_count ? snapc->snaps[index] : CEPH_NOSNAP; @@ -2148,16 +2169,20 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev) continue; } + snap_name = rbd_dev_v1_snap_info(rbd_dev, index, + &snap_size, &snap_features); + if (IS_ERR(snap_name)) + return PTR_ERR(snap_name); + dout("entry %u: snap_id = %llu\n", (unsigned int) snap_count, (unsigned long long) snap_id); if (!snap || (snap_id != CEPH_NOSNAP && snap->id < snap_id)) { - struct rbd_image_header *header = &rbd_dev->header; struct rbd_snap *new_snap; /* We haven't seen this snapshot before */ new_snap = __rbd_add_snap_dev(rbd_dev, snap_name, - snap_id, header->snap_sizes[index], 0); + snap_id, snap_size, snap_features); if (IS_ERR(new_snap)) { int err = PTR_ERR(new_snap); @@ -2178,9 +2203,9 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev) dout(" already present\n"); - rbd_assert(snap->size == - rbd_dev->header.snap_sizes[index]); + rbd_assert(snap->size == snap_size); rbd_assert(!strcmp(snap->name, snap_name)); + rbd_assert(snap->features == snap_features); /* Done with this list entry; advance */ @@ -2190,7 +2215,6 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev) /* Advance to the next entry in the snapshot context */ index++; - snap_name += strlen(snap_name) + 1; } dout("%s: done\n", __func__);