Re: [RFC 0/7] ext4: Allocator changes for atomic write support with DIO

From: John Garry
Date: Wed Dec 13 2023 - 04:25:22 EST


On 13/12/2023 06:42, Ojaswin Mujoo wrote:
Hi John,

So I don't seem to be able to hit the warn on:

$ touch mnt/testfile
$ ./test-pwritev2 -a -d -p 0 -l 4096 mnt/testfile

file=mnt/testfile write_size=4096 offset=0 o_flags=0x4002 wr_flags=0x24
main wrote 4096 bytes at offset 0

$ filefrag -v mnt/testfile

Filesystem type is: ef53
File size of testfile is 4096 (1 block of 4096 bytes)
ext: logical_offset: physical_offset: length: expected: flags:
0: 0.. 0: 32900.. 32900: 1: last,eof

$ ./test-pwritev2 -a -d -p 8192 -l 8192 mnt/testfile

file=mnt/testfile write_size=8192 offset=8192 o_flags=0x4002 wr_flags=0x24
main wrote 8192 bytes at offset 8192

$ filefrag -v mnt/testfile

Filesystem type is: ef53
File size of mnt/testfile is 16384 (4 blocks of 4096 bytes)
ext: logical_offset: physical_offset: length: expected: flags:
0: 0.. 0: 32900.. 32900: 1:
1: 2.. 3: 33288.. 33289: 2: 32902: last,eof
mnt/testfile: 2 extents found

Not sure why you are hitting the WARN_ON. The tree I used is:

Latest ted/dev + your atomic patchset v1 + this patchset

What commit/tree is ted/dev exactly?

Anyway, my v2 series is at https://github.com/johnpgarry/linux/commits/atomic-writes-v6.7-v2-blk

I'll try that later for ext4.

Thanks,
John