diff options
| author | Benjamin Coddington <ben.coddington@hammerspace.com> | 2026-09-15 08:22:09 -0400 |
|---|---|---|
| committer | Anna Schumaker <anna.schumaker@hammerspace.com> | 2026-10-05 09:46:43 -0400 |
| commit | 7f2d221b01f356b6bb3bb6efef998f8b28339824 (patch) | |
| tree | ce1288a3b3b4b9c5be2b741e2591b87fb64f3e70 | |
| parent | a84c62c4f03706b2c2f01dcc5fe614a4233ee75d (diff) | |
NFSv4/filelayout: Anchor page coalescing on pattern_offset
filelayout_pg_test() bounds page coalescing to a single stripe unit
using an offset relative to pls_range.offset, but the data server is
selected by nfs4_fl_calc_j_index() using an offset relative to
pattern_offset. When a segment's pattern_offset and range offset are
not congruent modulo the stripe unit, the coalescing window is shifted
off the DS-selection grid, so a coalesced I/O can straddle a stripe
boundary and send the bytes past it to the wrong data server.
Anchor coalescing on pattern_offset to match nfs4_fl_calc_j_index().
Stripe-congruent segments, including the common whole-file pattern_offset
0 case, are unchanged.
Fixes: c6194271f94b ("pnfs: filelayout: support non page aligned layouts")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Benjamin Coddington <bcodding@hammerspace.com>
Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>
| -rw-r--r-- | fs/nfs/filelayout/filelayout.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c index 72e20b56fbc7..0d53277f972e 100644 --- a/fs/nfs/filelayout/filelayout.c +++ b/fs/nfs/filelayout/filelayout.c @@ -796,7 +796,7 @@ filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, unsigned int size; u64 p_stripe, r_stripe; u32 stripe_offset; - u64 segment_offset = pgio->pg_lseg->pls_range.offset; + u64 pattern_offset = FILELAYOUT_LSEG(pgio->pg_lseg)->pattern_offset; u32 stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit; /* calls nfs_generic_pg_test */ @@ -808,8 +808,8 @@ filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, /* see if req and prev are in the same stripe */ if (prev) { - p_stripe = (u64)req_offset(prev) - segment_offset; - r_stripe = (u64)req_offset(req) - segment_offset; + p_stripe = (u64)req_offset(prev) - pattern_offset; + r_stripe = (u64)req_offset(req) - pattern_offset; do_div(p_stripe, stripe_unit); do_div(r_stripe, stripe_unit); @@ -818,7 +818,7 @@ filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, } /* calculate remaining bytes in the current stripe */ - div_u64_rem((u64)req_offset(req) - segment_offset, + div_u64_rem((u64)req_offset(req) - pattern_offset, stripe_unit, &stripe_offset); WARN_ON_ONCE(stripe_offset > stripe_unit); |