| Message ID | 51885E90.3080706@inktank.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 2403098..a7985d9 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -730,9 +730,10 @@ static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk) * Fill an rbd image header with information from the given format 1 * on-disk header. */ -static int rbd_header_from_disk(struct rbd_image_header *header, +static int rbd_header_from_disk(struct rbd_device *rbd_dev, struct rbd_image_header_ondisk *ondisk) { + struct rbd_image_header *header = &rbd_dev->header; bool first_time = header->object_prefix == NULL; struct ceph_snap_context *snapc;
Now that rbd_header_from_disk() only fills in one-time fields once, we can extend it slightly so it releases the other fields before replacing their values. This way there's no need to pass a temporary buffer and then copy all the results in. Just use the rbd device header structure in rbd_header_from_disk() so its values get updated directly. Note that this means we need to take the header semaphore at the point we update things. So pass the rbd_dev rather than the address of its header as its first argument to rbd_header_from_disk(), and have it return an error code. As a result, rbd_dev_v1_header_read() does all the work, rbd_read_header() becomes unnecessary, and rbd_dev_v1_refresh() becomes a very simple wrapper. Signed-off-by: Alex Elder <elder@inktank.com> --- drivers/block/rbd.c | 98 ++++++++++++++------------------------------------- 1 file changed, 27 insertions(+), 71 deletions(-) char *object_prefix = NULL; @@ -802,6 +803,7 @@ static int rbd_header_from_disk(struct rbd_image_header *header, /* We won't fail any more, fill in the header */ + down_write(&rbd_dev->header_rwsem); if (first_time) { header->object_prefix = object_prefix; header->obj_order = ondisk->options.order; @@ -811,6 +813,10 @@ static int rbd_header_from_disk(struct rbd_image_header *header, header->stripe_unit = 0; header->stripe_count = 0; header->features = 0; + } else { + ceph_put_snap_context(header->snapc); + kfree(header->snap_names); + kfree(header->snap_sizes); } /* The remaining fields always get updated (when we refresh) */ @@ -820,6 +826,14 @@ static int rbd_header_from_disk(struct rbd_image_header *header, header->snap_names = snap_names; header->snap_sizes = snap_sizes; + /* Make sure mapping size is consistent with header info */ + + if (rbd_dev->spec->snap_id == CEPH_NOSNAP || first_time) + if (rbd_dev->mapping.size != header->image_size) + rbd_dev->mapping.size = header->image_size; + + up_write(&rbd_dev->header_rwsem); + return 0; out_2big: ret = -EIO; @@ -3032,17 +3046,11 @@ out: } /* - * Read the complete header for the given rbd device. - * - * Returns a pointer to a dynamically-allocated buffer containing - * the complete and validated header. Caller can pass the address - * of a variable that will be filled in with the version of the - * header object at the time it was read. - * - * Returns a pointer-coded errno if a failure occurs. + * Read the complete header for the given rbd device. On successful + * return, the rbd_dev->header field will contain up-to-date + * information about the image. */ -static struct rbd_image_header_ondisk * -rbd_dev_v1_header_read(struct rbd_device *rbd_dev) +static int rbd_dev_v1_header_read(struct rbd_device *rbd_dev) { struct rbd_image_header_ondisk *ondisk = NULL; u32 snap_count = 0; @@ -3067,22 +3075,22 @@ rbd_dev_v1_header_read(struct rbd_device *rbd_dev) size += names_size; ondisk = kmalloc(size, GFP_KERNEL); if (!ondisk) - return ERR_PTR(-ENOMEM); + return -ENOMEM; ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_name, 0, size, ondisk); if (ret < 0) - goto out_err; + goto out; if ((size_t)ret < size) { ret = -ENXIO; rbd_warn(rbd_dev, "short header read (want %zd got %d)", size, ret); - goto out_err; + goto out; } if (!rbd_dev_ondisk_valid(ondisk)) { ret = -ENXIO; rbd_warn(rbd_dev, "invalid header"); - goto out_err; + goto out; } names_size = le64_to_cpu(ondisk->snap_names_len); @@ -3090,27 +3098,8 @@ rbd_dev_v1_header_read(struct rbd_device *rbd_dev) snap_count = le32_to_cpu(ondisk->snap_count); } while (snap_count != want_count); - return ondisk; - -out_err: - kfree(ondisk); - - return ERR_PTR(ret); -} - -/* - * reload the ondisk the header - */ -static int rbd_read_header(struct rbd_device *rbd_dev, - struct rbd_image_header *header) -{ - struct rbd_image_header_ondisk *ondisk; - int ret; - - ondisk = rbd_dev_v1_header_read(rbd_dev); - if (IS_ERR(ondisk)) - return PTR_ERR(ondisk); - ret = rbd_header_from_disk(header, ondisk); + ret = rbd_header_from_disk(rbd_dev, ondisk); +out: kfree(ondisk); return ret; @@ -3121,40 +3110,7 @@ static int rbd_read_header(struct rbd_device *rbd_dev, */ static int rbd_dev_v1_refresh(struct rbd_device *rbd_dev) { - int ret; - struct rbd_image_header h; - - memset(&h, 0, sizeof (h)); - ret = rbd_read_header(rbd_dev, &h); - if (ret < 0) - return ret; - - down_write(&rbd_dev->header_rwsem); - - /* Update image size, and check for resize of mapped image */ - rbd_dev->header.image_size = h.image_size; - if (rbd_dev->spec->snap_id == CEPH_NOSNAP) - if (rbd_dev->mapping.size != rbd_dev->header.image_size) - rbd_dev->mapping.size = rbd_dev->header.image_size; - - /* rbd_dev->header.object_prefix shouldn't change */ - kfree(rbd_dev->header.snap_sizes); - kfree(rbd_dev->header.snap_names); - /* osd requests may still refer to snapc */ - ceph_put_snap_context(rbd_dev->header.snapc); - - rbd_dev->header.image_size = h.image_size; - rbd_dev->header.snapc = h.snapc; - rbd_dev->header.snap_names = h.snap_names; - rbd_dev->header.snap_sizes = h.snap_sizes; - /* Free the extra copy of the object prefix */ - if (strcmp(rbd_dev->header.object_prefix, h.object_prefix)) - rbd_warn(rbd_dev, "object prefix changed (ignoring)"); - kfree(h.object_prefix); - - up_write(&rbd_dev->header_rwsem); - - return ret; + return rbd_dev_v1_header_read(rbd_dev); } /* @@ -4517,7 +4473,7 @@ static int rbd_dev_v1_probe(struct rbd_device *rbd_dev) /* Populate rbd image metadata */ - ret = rbd_read_header(rbd_dev, &rbd_dev->header); + ret = rbd_dev_v1_header_read(rbd_dev); if (ret < 0) goto out_err;