Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add functions to read/write plain old data (POD) types. #117

Merged
merged 1 commit into from
Mar 21, 2021
Merged

Conversation

wedsonaf
Copy link

Other minor changes:

  • Made UserSlicePtr::new public. This is to allow drivers to access user
    buffers that don't come directly from file operations.
  • Ability to clone UserSlicePtr. This is for cases when we need to read
    then write; so we clone before creating a reader/writer.

rust/kernel/user_ptr.rs Outdated Show resolved Hide resolved
rust/kernel/user_ptr.rs Outdated Show resolved Hide resolved
rust/kernel/user_ptr.rs Outdated Show resolved Hide resolved
Other minor changes:
* Made UserSlicePtr::new public. This is to allow drivers to access user
buffers that don't come directly from file operations.
* Added a function to get both a reader and a writer from UserSlicePtr.
@wedsonaf
Copy link
Author

@ojeda -- would you be able to push wedsonaf@176ba9e to this PR for me again?

Hopefully we can push this and everything else will be through my fork.

@ojeda
Copy link
Member

ojeda commented Mar 21, 2021

No problem at all -- done!

@ojeda ojeda merged commit 832575d into rust Mar 21, 2021
@ojeda ojeda deleted the user_ptr branch March 21, 2021 17:54
ojeda pushed a commit that referenced this pull request Apr 10, 2023
XFS allows CoW on non-shared extents to combat fragmentation[1].  The old
non-shared extent could be mwrited before, its dax entry is marked dirty. 

This results in a WARNing:

[   28.512349] ------------[ cut here ]------------
[   28.512622] WARNING: CPU: 2 PID: 5255 at fs/dax.c:390 dax_insert_entry+0x342/0x390
[   28.513050] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs lockd grace fscache netfs nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables
[   28.515462] CPU: 2 PID: 5255 Comm: fsstress Kdump: loaded Not tainted 6.3.0-rc1-00001-g85e1481e19c1-dirty #117
[   28.515902] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Arch Linux 1.16.1-1-1 04/01/2014
[   28.516307] RIP: 0010:dax_insert_entry+0x342/0x390
[   28.516536] Code: 30 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 8b 45 20 48 83 c0 01 e9 e2 fe ff ff 48 8b 45 20 48 83 c0 01 e9 cd fe ff ff <0f> 0b e9 53 ff ff ff 48 8b 7c 24 08 31 f6 e8 1b 61 a1 00 eb 8c 48
[   28.517417] RSP: 0000:ffffc9000845fb18 EFLAGS: 00010086
[   28.517721] RAX: 0000000000000053 RBX: 0000000000000155 RCX: 000000000018824b
[   28.518113] RDX: 0000000000000000 RSI: ffffffff827525a6 RDI: 00000000ffffffff
[   28.518515] RBP: ffffea00062092c0 R08: 0000000000000000 R09: ffffc9000845f9c8
[   28.518905] R10: 0000000000000003 R11: ffffffff82ddb7e8 R12: 0000000000000155
[   28.519301] R13: 0000000000000000 R14: 000000000018824b R15: ffff88810cfa76b8
[   28.519703] FS:  00007f14a0c94740(0000) GS:ffff88817bd00000(0000) knlGS:0000000000000000
[   28.520148] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   28.520472] CR2: 00007f14a0c8d000 CR3: 000000010321c004 CR4: 0000000000770ee0
[   28.520863] PKRU: 55555554
[   28.521043] Call Trace:
[   28.521219]  <TASK>
[   28.521368]  dax_fault_iter+0x196/0x390
[   28.521595]  dax_iomap_pte_fault+0x19b/0x3d0
[   28.521852]  __xfs_filemap_fault+0x234/0x2b0
[   28.522116]  __do_fault+0x30/0x130
[   28.522334]  do_fault+0x193/0x340
[   28.522586]  __handle_mm_fault+0x2d3/0x690
[   28.522975]  handle_mm_fault+0xe6/0x2c0
[   28.523259]  do_user_addr_fault+0x1bc/0x6f0
[   28.523521]  exc_page_fault+0x60/0x140
[   28.523763]  asm_exc_page_fault+0x22/0x30
[   28.524001] RIP: 0033:0x7f14a0b589ca
[   28.524225] Code: c5 fe 7f 07 c5 fe 7f 47 20 c5 fe 7f 47 40 c5 fe 7f 47 60 c5 f8 77 c3 66 0f 1f 84 00 00 00 00 00 40 0f b6 c6 48 89 d1 48 89 fa <f3> aa 48 89 d0 c5 f8 77 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90
[   28.525198] RSP: 002b:00007fff1dea1c98 EFLAGS: 00010202
[   28.525505] RAX: 000000000000001e RBX: 000000000014a000 RCX: 0000000000006046
[   28.525895] RDX: 00007f14a0c82000 RSI: 000000000000001e RDI: 00007f14a0c8d000
[   28.526290] RBP: 000000000000006f R08: 0000000000000004 R09: 000000000014a000
[   28.526681] R10: 0000000000000008 R11: 0000000000000246 R12: 028f5c28f5c28f5c
[   28.527067] R13: 8f5c28f5c28f5c29 R14: 0000000000011046 R15: 00007f14a0c946c0
[   28.527449]  </TASK>
[   28.527600] ---[ end trace 0000000000000000 ]---


To be able to delete this entry, clear its dirty mark before
invalidate_inode_pages2_range().

[1] https://lore.kernel.org/linux-xfs/20230321151339.GA11376@frogsfrogsfrogs/

Link: https://lkml.kernel.org/r/[email protected]
Fixes: f80e166 ("fsdax: invalidate pages when CoW")
Signed-off-by: Shiyang Ruan <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Darrick J. Wong <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Development

Successfully merging this pull request may close these issues.

3 participants