| Message ID | 20210216164527.37745-3-vsementsov@virtuozzo.com |
|---|---|
| State | New |
| Headers | show |
| Series | parallels: load bitmap extension | expand |
On 2/16/21 7:45 PM, Vladimir Sementsov-Ogievskiy wrote: > Actually L1 table entry offset is in 512 bytes sectors. Fix the spec. > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> > --- > docs/interop/parallels.txt | 15 +++++++++------ > 1 file changed, 9 insertions(+), 6 deletions(-) > > diff --git a/docs/interop/parallels.txt b/docs/interop/parallels.txt > index f15bf35bd1..ebbdd1b25b 100644 > --- a/docs/interop/parallels.txt > +++ b/docs/interop/parallels.txt > @@ -209,15 +209,14 @@ of its data area are: > The number of entries in the L1 table of the bitmap. > > variable: l1_table (8 * l1_size bytes) > - L1 offset table (in bytes) this change is unclear. First, we have specified here the size of this table. It is (8 * l1_size bytes). Thus it would be MUCH better to say l1_table (size: 8 * l1_size bytes) or L1 offset table (l1_table), size: 8 * l1_size bytes or something like this. > > A dirty bitmap is stored using a one-level structure for the mapping to host > -clusters - an L1 table. > +clusters - an L1 table. Each L1 table entry is a 64bit integer described > +below: > > -Given an offset in bytes into the bitmap data, the offset in bytes into the > -image file can be obtained as follows: > +Given an offset in bytes into the bitmap data, corresponding L1 entry is > > - offset = l1_table[offset / cluster_size] + (offset % cluster_size) > + l1_table[offset / cluster_size] Dirty bitmap is stored in the array of clusters inside Parallels Image file. Offsets of these clusters are saved in L1 offset table here. > > If an L1 table entry is 0, the corresponding cluster of the bitmap is assumed > to be zero. If L1 table entry is 0, all bits in the corresponding cluster of the bitmap are assumed to be 0. > @@ -225,4 +224,8 @@ to be zero. > If an L1 table entry is 1, the corresponding cluster of the bitmap is assumed > to have all bits set. If L1 table entry is 1, all bits in the corresponding cluster of the bitmap are assumed to be 1. > > -If an L1 table entry is not 0 or 1, it allocates a cluster from the data area. > +If an L1 table entry is not 0 or 1, it contains corresponding cluster offset > +(in 512b sectors). Given an offset in bytes into the bitmap data the offset in > +bytes into the image file can be obtained as follows: > + > + offset = l1_table[offset / cluster_size] * 512 + (offset % cluster_size) looks good
diff --git a/docs/interop/parallels.txt b/docs/interop/parallels.txt index f15bf35bd1..ebbdd1b25b 100644 --- a/docs/interop/parallels.txt +++ b/docs/interop/parallels.txt @@ -209,15 +209,14 @@ of its data area are: The number of entries in the L1 table of the bitmap. variable: l1_table (8 * l1_size bytes) - L1 offset table (in bytes) A dirty bitmap is stored using a one-level structure for the mapping to host -clusters - an L1 table. +clusters - an L1 table. Each L1 table entry is a 64bit integer described +below: -Given an offset in bytes into the bitmap data, the offset in bytes into the -image file can be obtained as follows: +Given an offset in bytes into the bitmap data, corresponding L1 entry is - offset = l1_table[offset / cluster_size] + (offset % cluster_size) + l1_table[offset / cluster_size] If an L1 table entry is 0, the corresponding cluster of the bitmap is assumed to be zero. @@ -225,4 +224,8 @@ to be zero. If an L1 table entry is 1, the corresponding cluster of the bitmap is assumed to have all bits set. -If an L1 table entry is not 0 or 1, it allocates a cluster from the data area. +If an L1 table entry is not 0 or 1, it contains corresponding cluster offset +(in 512b sectors). Given an offset in bytes into the bitmap data the offset in +bytes into the image file can be obtained as follows: + + offset = l1_table[offset / cluster_size] * 512 + (offset % cluster_size)
Actually L1 table entry offset is in 512 bytes sectors. Fix the spec. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> --- docs/interop/parallels.txt | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)