imrcpan/freebsd
1
0 Fork 0
mirror of https://github.com/freebsd/freebsd-src.git synced 2026-10-28 19:34:43 +01:00
Code Issues Packages Projects Releases Wiki Activity

Overflowing refreservation is bad

Browse Source 
Someone came to me and pointed out that you could pretty
readily cause the refreservation calculation to exceed
2**64, given the 2**17 multiplier in it, and produce
refreservations wildly less than the actual volsize in cases where
it should have failed.

Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Rich Ercolani <[email protected]>
Closes #15996
This commit is contained in:
Rich Ercolani authored and GitHub committed 2024-04-29 11:32:49 -07:00
1 parent 4840f023af
commit db499e68f9
1 file changed
+14 -1
Download Patch File Download Diff File Expand all files Collapse all files
lib/libzfs/libzfs_dataset.c
+14 -1
View File
@@ -5565,8 +5565,21 @@ volsize_from_vdevs(zpool_handle_t *zhp, uint64_t nblocks, uint64_t blksize)
/*
* Scale this size down as a ratio of 128k / tsize.
* See theory statement above.
*
* Bitshift is to avoid the case of nblocks * asize < tsize
* producing a size of 0.
*/
volsize = nblocks * asize * SPA_OLD_MAXBLOCKSIZE / tsize;
volsize = (nblocks * asize) / (tsize >> SPA_MINBLOCKSHIFT);
/*
* If we would blow UINT64_MAX with this next multiplication,
* don't.
*/
if (volsize >
(UINT64_MAX / (SPA_OLD_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT)))
volsize = UINT64_MAX;
else
volsize *= (SPA_OLD_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
if (volsize > ret) {
ret = volsize;
}