kernel/linux.git/fs/nfs/write.c, branch v5.15.208

NFS: check if suid/sgid was cleared after a write as needed

2025-12-06T21:09:27+00:00

[ Upstream commit 9ff022f3820a31507cb93be6661bf5f3ca0609a4 ] I noticed xfstests generic/193 and generic/355 started failing against knfsd after commit e7a8ebc305f2 ("NFSD: Offer write delegation for OPEN with OPEN4_SHARE_ACCESS_WRITE"). I ran those same tests against ONTAP (which has had write delegation support for a lot longer than knfsd) and they fail there too... so while it's a new failure against knfsd, it isn't an entirely new failure. Add the NFS_INO_REVAL_FORCED flag so that the presence of a delegation doesn't keep the inode from being revalidated to fetch the updated mode. Signed-off-by: Scott Mayhew Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin

NFS: Fix a race when updating an existing write

2025-09-04T12:28:44+00:00

commit 76d2e3890fb169168c73f2e4f8375c7cc24a765e upstream. After nfs_lock_and_join_requests() tests for whether the request is still attached to the mapping, nothing prevents a call to nfs_inode_remove_request() from succeeding until we actually lock the page group. The reason is that whoever called nfs_inode_remove_request() doesn't necessarily have a lock on the page group head. So in order to avoid races, let's take the page group lock earlier in nfs_lock_and_join_requests(), and hold it across the removal of the request in nfs_inode_remove_request(). Reported-by: Jeff Layton Tested-by: Joe Quanaim Tested-by: Andrew Steffen Reviewed-by: Jeff Layton Fixes: bd37d6fce184 ("NFSv4: Convert nfs_lock_and_join_requests() to use nfs_page_find_head_request()") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

nfs: fold nfs_page_group_lock_subrequests into nfs_lock_and_join_requests

2025-09-04T12:28:44+00:00

commit 25edbcac6e32eab345e470d56ca9974a577b878b upstream. Fold nfs_page_group_lock_subrequests into nfs_lock_and_join_requests to prepare for future changes to this code, and move the helpers to write.c as well. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Signed-off-by: Anna Schumaker Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

NFS: nfs_async_write_reschedule_io must not recurse into the writeback code

2024-12-14T18:50:38+00:00

commit b1a28f2eb9ea7a5a1763fe53fe699aa0feae4231 upstream. It is not safe to call filemap_fdatawrite_range() from nfs_async_write_reschedule_io(), since we're often calling from a page reclaim context. Just let fsync() redrive the writeback for us. Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

nfs: fix UAF in direct writes

2024-04-10T14:18:40+00:00

[ Upstream commit 17f46b803d4f23c66cacce81db35fef3adb8f2af ] In production we have been hitting the following warning consistently ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 17 PID: 1800359 at lib/refcount.c:28 refcount_warn_saturate+0x9c/0xe0 Workqueue: nfsiod nfs_direct_write_schedule_work [nfs] RIP: 0010:refcount_warn_saturate+0x9c/0xe0 PKRU: 55555554 Call Trace: ? __warn+0x9f/0x130 ? refcount_warn_saturate+0x9c/0xe0 ? report_bug+0xcc/0x150 ? handle_bug+0x3d/0x70 ? exc_invalid_op+0x16/0x40 ? asm_exc_invalid_op+0x16/0x20 ? refcount_warn_saturate+0x9c/0xe0 nfs_direct_write_schedule_work+0x237/0x250 [nfs] process_one_work+0x12f/0x4a0 worker_thread+0x14e/0x3b0 ? ZSTD_getCParams_internal+0x220/0x220 kthread+0xdc/0x120 ? __btf_name_valid+0xa0/0xa0 ret_from_fork+0x1f/0x30 This is because we're completing the nfs_direct_request twice in a row. The source of this is when we have our commit requests to submit, we process them and send them off, and then in the completion path for the commit requests we have if (nfs_commit_end(cinfo.mds)) nfs_direct_write_complete(dreq); However since we're submitting asynchronous requests we sometimes have one that completes before we submit the next one, so we end up calling complete on the nfs_direct_request twice. The only other place we use nfs_generic_commit_list() is in __nfs_commit_inode, which wraps this call in a nfs_commit_begin(); nfs_commit_end(); Which is a common pattern for this style of completion handling, one that is also repeated in the direct code with get_dreq()/put_dreq() calls around where we process events as well as in the completion paths. Fix this by using the same pattern for the commit requests. Before with my 200 node rocksdb stress running this warning would pop every 10ish minutes. With my patch the stress test has been running for several hours without popping. Signed-off-by: Josef Bacik Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

NFS: Use the correct commit info in nfs_join_page_group()

2023-10-06T11:17:59+00:00

[ Upstream commit b193a78ddb5ee7dba074d3f28dc050069ba083c0 ] Ensure that nfs_clear_request_commit() updates the correct counters when it removes them from the commit list. Fixes: ed5d588fe47f ("NFS: Try to join page groups before an O_DIRECT retransmission") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin

NFS: Fix another fsync() issue after a server reboot

2022-09-15T09:30:03+00:00

[ Upstream commit 67f4b5dc49913abcdb5cc736e73674e2f352f81d ] Currently, when the writeback code detects a server reboot, it redirties any pages that were not committed to disk, and it sets the flag NFS_CONTEXT_RESEND_WRITES in the nfs_open_context of the file descriptor that dirtied the file. While this allows the file descriptor in question to redrive its own writes, it violates the fsync() requirement that we should be synchronising all writes to disk. While the problem is infrequent, we do see corner cases where an untimely server reboot causes the fsync() call to abandon its attempt to sync data to disk and causing data corruption issues due to missed error conditions or similar. In order to tighted up the client's ability to deal with this situation without introducing livelocks, add a counter that records the number of times pages are redirtied due to a server reboot-like condition, and use that in fsync() to redrive the sync to disk. Fixes: 2197e9b06c22 ("NFS: Fix up fsync() when the server rebooted") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

NFSv4.1 mark qualified async operations as MOVEABLE tasks

2022-06-09T08:23:17+00:00

[ Upstream commit 118f09eda21d392e1eeb9f8a4bee044958cccf20 ] Mark async operations such as RENAME, REMOVE, COMMIT MOVEABLE for the nfsv4.1+ sessions. Fixes: 85e39feead948 ("NFSv4.1 identify and mark RPC tasks that can move between transports") Signed-off-by: Olga Kornievskaia Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin

NFS: Further fixes to the writeback error handling

2022-06-09T08:23:15+00:00

[ Upstream commit c6fd3511c3397dd9cbc6dc5d105bbedb69bf4061 ] When we handle an error by redirtying the page, we're not corrupting the mapping, so we don't want the error to be recorded in the mapping. If the caller has specified a sync_mode of WB_SYNC_NONE, we can just return AOP_WRITEPAGE_ACTIVATE. However if we're dealing with WB_SYNC_ALL, we need to ensure that retries happen when the errors are non-fatal. Reported-by: Olga Kornievskaia Fixes: 8fc75bed96bb ("NFS: Fix up return value on fatal errors in nfs_page_async_flush()") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin

NFS: Don't report errors from nfs_pageio_complete() more than once

2022-06-09T08:23:15+00:00

[ Upstream commit c5e483b77cc2edb318da152abe07e33006b975fd ] Since errors from nfs_pageio_complete() are already being reported through nfs_async_write_error(), we should not be returning them to the callers of do_writepages() as well. They will end up being reported through the generic mechanism instead. Fixes: 6fbda89b257f ("NFS: Replace custom error reporting mechanism with generic one") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin