kernel/linux.git/fs/nfs/flexfilelayout, branch v6.12.101

NFSv4/flexfiles: honor FF_FLAGS_NO_IO_THRU_MDS in pg_get_mirror_count_write

2026-07-24T14:11:07+00:00

[ Upstream commit 1d62e659c0bf11649cf48e002c2a55d148f2610a ] The FF_FLAGS_NO_IO_THRU_MDS flag lives on each lseg, so any fallback decision made when there is no current lseg (e.g. between LAYOUTRETURN and the next LAYOUTGET) cannot run the per-lseg check. Introduce a sticky hdr-level ditto for FF_FLAGS_NO_IO_THRU_MDS in struct nfs4_flexfile_layout::flags (NFS4_FF_HDR_NO_IO_THRU_MDS bit), set whenever ff_layout_alloc_lseg() parses an lseg with the flag. The bit is never cleared for the lifetime of the layout hdr; the server is assumed to be consistent in its no-fallback policy per file. kzalloc() in ff_layout_alloc_layout_hdr() zero-initializes the field. Use the new ff_layout_hdr_no_fallback_to_mds() helper to gate ff_layout_pg_get_mirror_count_write(): when pnfs_update_layout() returns NULL (e.g. NFS_LAYOUT_BULK_RECALL, pnfs_layout_io_test_failed, pnfs_layoutgets_blocked) the existing code unconditionally calls nfs_pageio_reset_write_mds(). This is a source of unwanted WRITE to MDS. Fix it by checking NFS4_FF_HDR_NO_IO_THRU_MDS bit, and if set surface -EAGAIN instead; the writepage-side caller (nfs_do_writepage() for buffered, nfs_direct_write_reschedule() for O_DIRECT) then redirties the request so writeback retries via pNFS. Fixes: 260074cd8413 ("pNFS/flexfiles: Add support for FF_FLAGS_NO_IO_THRU_MDS") Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Mike Snitzer Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin

NFSv4/flexfiles: honor FF_FLAGS_NO_IO_THRU_MDS on fatal DS connect errors

2026-07-24T14:11:07+00:00

[ Upstream commit 7a375cafc14ed151508f908ea5681caf0a9cc1d6 ] Commit f06bedfa62d5 ("pNFS/flexfiles: don't attempt pnfs on fatal DS errors") teaches ff_layout_{read,write}_pagelist() to return PNFS_NOT_ATTEMPTED when nfs4_ff_layout_prepare_ds() fails with a nfs_error_is_fatal() errno (e.g. -ETIMEDOUT from a SOFTCONN connect deadline, -ENOMEM, -ERESTARTSYS), so that the client gives up instead of spinning. pnfs_do_{read,write}() then dispatches the I/O through pnfs_{read,write}_through_mds() → nfs_pageio_reset_{read,write}_mds(). That fallback is unconditional and silently violates FF_FLAGS_NO_IO_THRU_MDS: when the layout segment carries the flag (typically single-mirror appliance layouts where MDS I/O is explicitly forbidden), the out_failed: path's \`&& !ds_fatal_error\` clause overrides the flag's short-circuit through ff_layout_avoid_mds_available_ds() and routes the I/O to the MDS file handle anyway. This is reachable in practice during a data-server restart: SOFTCONN exhaustion produces -ETIMEDOUT, which is fatal per nfs_error_is_fatal(), which triggers PNFS_NOT_ATTEMPTED, which silently goes to MDS. Preserve the upstream "don't spin on fatal errors" intent for layouts that permit MDS fallback. For layouts with FF_FLAGS_NO_IO_THRU_MDS set, mark the layout for return and request PNFS_TRY_AGAIN instead; if the server cannot supply a usable layout the failure now surfaces cleanly via pnfs_update_layout(), rather than via silent MDS I/O that contradicts the flag. Fixes: f06bedfa62d5 ("pNFS/flexfiles: don't attempt pnfs on fatal DS errors") Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Mike Snitzer Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin

NFSv4/flexfiles: reject zero filehandle version count

2026-07-18T14:51:55+00:00

[ Upstream commit 2c6bb3c40bc24f6aa8dfbe6fe98c3ad6389203f2 ] ff_layout_alloc_lseg() decodes the filehandle-version array count from the flexfiles layout body. The value is used as the count for kzalloc_objs(), and the current code only rejects NULL. A zero count yields ZERO_SIZE_PTR, which can be stored in dss_info->fh_versions even though later flexfiles paths assume that at least one filehandle version exists. Reject fh_count == 0 before the allocation, matching the existing zero version_count validation in the flexfiles GETDEVICEINFO parser. A QEMU/KASAN run with a malformed flexfiles layout hit: KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:ff_layout_encode_ff_layoutupdate.isra.0+0x15f/0x750 ff_layout_encode_layoutreturn+0x683/0x970 nfs4_xdr_enc_layoutreturn+0x278/0x3a0 Kernel panic - not syncing: Fatal exception The patched kernel rejects the malformed layout without KASAN/oops/panic, and a valid fh_count=1 regression still opens, reads, and unmounts cleanly. Cc: stable@vger.kernel.org Fixes: d67ae825a59d ("pnfs/flexfiles: Add the FlexFile Layout Driver") Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

NFSv4/flexfiles: Add data structure support for striped layouts

2026-07-18T14:51:55+00:00

[ Upstream commit d442670c0f63c46b7f348f68fb2002af597708f2 ] Adds a new struct nfs4_ff_layout_ds_stripe that represents a data server stripe within a layout. A new dynamically allocated array of this type has been added to nfs4_ff_layout_mirror and per stripe configuration information has been moved from the mirror type to the stripe based on the RFC. Signed-off-by: Jonathan Curley Signed-off-by: Anna Schumaker Stable-dep-of: 2c6bb3c40bc2 ("NFSv4/flexfiles: reject zero filehandle version count") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

NFSv4/flexfiles: Remove cred local variable dependency

2026-07-18T14:51:55+00:00

[ Upstream commit fec80afc41afa3016421115427df8d00dc491ee5 ] No-op preparation change to remove dependency on cred local variable. Subsequent striping diff has a cred per stripe so this local variable can't be trusted to be the same. Signed-off-by: Jonathan Curley Signed-off-by: Anna Schumaker Stable-dep-of: 2c6bb3c40bc2 ("NFSv4/flexfiles: reject zero filehandle version count") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

pnfs/flexfiles: Fix memory leak in nfs4_ff_alloc_deviceid_node()

2026-01-23T10:18:36+00:00

[ Upstream commit 0c728083654f0066f5e10a1d2b0bd0907af19a58 ] In nfs4_ff_alloc_deviceid_node(), if the allocation for ds_versions fails, the function jumps to the out_scratch label without freeing the already allocated dsaddrs list, leading to a memory leak. Fix this by jumping to the out_err_drain_dsaddrs label, which properly frees the dsaddrs list before cleaning up other resources. Fixes: d67ae825a59d6 ("pnfs/flexfiles: Add the FlexFile Layout Driver") Signed-off-by: Zilin Guan Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

NFSv4/flexfiles: Fix layout merge mirror check.

2025-09-19T14:35:44+00:00

[ Upstream commit dd2fa82473453661d12723c46c9f43d9876a7efd ] Typo in ff_lseg_match_mirrors makes the diff ineffective. This results in merge happening all the time. Merge happening all the time is problematic because it marks lsegs invalid. Marking lsegs invalid causes all outstanding IO to get restarted with EAGAIN and connections to get closed. Closing connections constantly triggers race conditions in the RDMA implementation... Fixes: 660d1eb22301c ("pNFS/flexfile: Don't merge layout segments if the mirrors don't match") Signed-off-by: Jonathan Curley Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

flexfiles/pNFS: fix NULL checks on result of ff_layout_choose_ds_for_read

2025-09-19T14:35:43+00:00

[ Upstream commit 5a46d2339a5ae268ede53a221f20433d8ea4f2f9 ] Recent commit f06bedfa62d5 ("pNFS/flexfiles: don't attempt pnfs on fatal DS errors") has changed the error return type of ff_layout_choose_ds_for_read() from NULL to an error pointer. However, not all code paths have been updated to match the change. Thus, some non-NULL checks will accept error pointers as a valid return value. Reported-by: Dan Carpenter Suggested-by: Dan Carpenter Fixes: f06bedfa62d5 ("pNFS/flexfiles: don't attempt pnfs on fatal DS errors") Signed-off-by: Tigran Mkrtchyan Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

pNFS/flexfiles: don't attempt pnfs on fatal DS errors

2025-08-15T10:14:04+00:00

[ Upstream commit f06bedfa62d57f7b67d44aacd6badad2e13a803f ] When an applications get killed (SIGTERM/SIGINT) while pNFS client performs a connection to DS, client ends in an infinite loop of connect-disconnect. This source of the issue, it that flexfilelayoutdev#nfs4_ff_layout_prepare_ds gets an error on nfs4_pnfs_ds_connect with status ERESTARTSYS, which is set by rpc_signal_task, but the error is treated as transient, thus retried. The issue is reproducible with Ctrl+C the following script(there should be ~1000 files in a directory, client should must not have any connections to DSes): ``` echo 3 > /proc/sys/vm/drop_caches for i in * do head -1 $i done ``` The change aims to propagate the nfs4_ff_layout_prepare_ds error state to the caller that can decide whatever this is a retryable error or not. Signed-off-by: Tigran Mkrtchyan Link: https://lore.kernel.org/r/20250627071751.189663-1-tigran.mkrtchyan@desy.de Fixes: 260f32adb88d ("pNFS/flexfiles: Check the result of nfs4_pnfs_ds_connect") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

NFSv4/flexfiles: Fix handling of NFS level errors in I/O

2025-07-10T14:05:09+00:00

[ Upstream commit 38074de35b015df5623f524d6f2b49a0cd395c40 ] Allow the flexfiles error handling to recognise NFS level errors (as opposed to RPC level errors) and handle them separately. The main motivator is the NFSERR_PERM errors that get returned if the NFS client connects to the data server through a port number that is lower than 1024. In that case, the client should disconnect and retry a READ on a different data server, or it should retry a WRITE after reconnecting. Reviewed-by: Tigran Mkrtchyan Fixes: d67ae825a59d ("pnfs/flexfiles: Add the FlexFile Layout Driver") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin