On Wed, Jul 18, 2018 at 7:30 AM, Austin S. Hemmelgarn <ahferro...@gmail.com> wrote:
> > I'm not sure. In this particular case, this will fail on BTRFS for any X > larger than just short of one third of the total free space. I would expect > it to fail for any X larger than just short of half instead. I'm confused. I can't get it to fail when X is 3/4 of free space. lvcreate -V 2g -T vg/thintastic -n btrfstest mkfs.btrfs -M /dev/mapper/vg-btrfstest mount /dev/mapper/vg-btrfstest /mnt/btrfs cd /mnt/btrfs fallocate -l 1500m tmp dd if=/dev/zero of=/mnt/btrfs/tmp bs=1M count=1450 Succeeds. No enospc. This is on kernel 4.17.6. Copied from terminal: [chris@f28s btrfs]$ df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg-btrfstest 2.0G 17M 2.0G 1% /mnt/btrfs [chris@f28s btrfs]$ sudo fallocate -l 1500m /mnt/btrfs/tmp [chris@f28s btrfs]$ filefrag -v tmp Filesystem type is: 9123683e File size of tmp is 1572864000 (384000 blocks of 4096 bytes) ext: logical_offset: physical_offset: length: expected: flags: 0: 0.. 32767: 16400.. 49167: 32768: unwritten 1: 32768.. 65535: 56576.. 89343: 32768: 49168: unwritten 2: 65536.. 98303: 109824.. 142591: 32768: 89344: unwritten 3: 98304.. 131071: 163072.. 195839: 32768: 142592: unwritten 4: 131072.. 163839: 216320.. 249087: 32768: 195840: unwritten 5: 163840.. 196607: 269568.. 302335: 32768: 249088: unwritten 6: 196608.. 229375: 322816.. 355583: 32768: 302336: unwritten 7: 229376.. 262143: 376064.. 408831: 32768: 355584: unwritten 8: 262144.. 294911: 429312.. 462079: 32768: 408832: unwritten 9: 294912.. 327679: 482560.. 515327: 32768: 462080: unwritten 10: 327680.. 344063: 89344.. 105727: 16384: 515328: unwritten 11: 344064.. 360447: 142592.. 158975: 16384: 105728: unwritten 12: 360448.. 376831: 195840.. 212223: 16384: 158976: unwritten 13: 376832.. 383999: 249088.. 256255: 7168: 212224: last,unwritten,eof tmp: 14 extents found [chris@f28s btrfs]$ df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg-btrfstest 2.0G 1.5G 543M 74% /mnt/btrfs [chris@f28s btrfs]$ sudo dd if=/dev/zero of=/mnt/btrfs/tmp bs=1M count=1450 1450+0 records in 1450+0 records out 1520435200 bytes (1.5 GB, 1.4 GiB) copied, 13.4757 s, 113 MB/s [chris@f28s btrfs]$ df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg-btrfstest 2.0G 1.5G 591M 72% /mnt/btrfs [chris@f28s btrfs]$ filefrag -v tmp Filesystem type is: 9123683e File size of tmp is 1520435200 (371200 blocks of 4096 bytes) ext: logical_offset: physical_offset: length: expected: flags: 0: 0.. 16383: 302336.. 318719: 16384: 1: 16384.. 32767: 355584.. 371967: 16384: 318720: 2: 32768.. 49151: 408832.. 425215: 16384: 371968: 3: 49152.. 65535: 462080.. 478463: 16384: 425216: 4: 65536.. 73727: 515328.. 523519: 8192: 478464: 5: 73728.. 86015: 3328.. 15615: 12288: 523520: 6: 86016.. 98303: 256256.. 268543: 12288: 15616: 7: 98304.. 104959: 49168.. 55823: 6656: 268544: 8: 104960.. 109047: 105728.. 109815: 4088: 55824: 9: 109048.. 113143: 158976.. 163071: 4096: 109816: 10: 113144.. 117239: 212224.. 216319: 4096: 163072: 11: 117240.. 121335: 318720.. 322815: 4096: 216320: 12: 121336.. 125431: 371968.. 376063: 4096: 322816: 13: 125432.. 128251: 425216.. 428035: 2820: 376064: 14: 128252.. 131071: 478464.. 481283: 2820: 428036: 15: 131072.. 132409: 1460.. 2797: 1338: 481284: 16: 132410.. 165177: 322816.. 355583: 32768: 2798: 17: 165178.. 197945: 376064.. 408831: 32768: 355584: 18: 197946.. 230713: 429312.. 462079: 32768: 408832: 19: 230714.. 263481: 482560.. 515327: 32768: 462080: 20: 263482.. 296249: 16400.. 49167: 32768: 515328: 21: 296250.. 327687: 56576.. 88013: 31438: 49168: 22: 327688.. 328711: 428036.. 429059: 1024: 88014: 23: 328712.. 361479: 109824.. 142591: 32768: 429060: 24: 361480.. 371199: 88014.. 97733: 9720: 142592: last,eof tmp: 25 extents found [chris@f28s btrfs]$ *shrug* -- Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
