[PATCH v5 08/12] nfs: drop usage of folio_file_pos

Kairui Song
2024-05-10T11:50:26Z

folio_file_pos is only needed for mixed usage of page cache and
swap cache, for pure page cache usage, the caller can just use
folio_pos instead.

After commit e1209d3a7a67 ("mm: introduce ->swap_rw and use it for
reads from SWP_FS_OPS swap-space"), swap cache should never be exposed
to nfs.

So remove the usage of folio_file_pos in following NFS functions / helpers:

- nfs_vm_page_mkwrite

It's only used by nfs_file_vm_ops.page_mkwrite

- trace event helper: nfs_folio_event
- trace event helper: nfs_folio_event_done

These two are used through DEFINE_NFS_FOLIO_EVENT and
DEFINE_NFS_FOLIO_EVENT_DONE, which defined following events:

- trace_nfs_aop_readpage{_done}: only called by nfs_read_folio
- trace_nfs_writeback_folio: only called by nfs_wb_folio
- trace_nfs_invalidate_folio: only called by nfs_invalidate_folio
- trace_nfs_launder_folio_done: only called by nfs_launder_folio

None of them could possibly be used on swap cache folio,
nfs_read_folio only called by:
.write_begin -> nfs_read_folio
.read_folio

nfs_wb_folio only called by nfs mapping:
.release_folio -> nfs_wb_folio
.launder_folio -> nfs_wb_folio
.write_begin -> nfs_read_folio -> nfs_wb_folio
.read_folio -> nfs_wb_folio
.write_end -> nfs_update_folio -> nfs_writepage_setup -> nfs_setup_write_request -> nfs_try_to_update_request -> nfs_wb_folio
.page_mkwrite -> nfs_update_folio -> nfs_writepage_setup -> nfs_setup_write_request -> nfs_try_to_update_request -> nfs_wb_folio
.write_begin -> nfs_flush_incompatible -> nfs_wb_folio
.page_mkwrite -> nfs_vm_page_mkwrite -> nfs_flush_incompatible -> nfs_wb_folio

nfs_invalidate_folio is only called by .invalidate_folio.
nfs_launder_folio is only called by .launder_folio

- nfs_grow_file
- nfs_update_folio

nfs_grow_file is only called by nfs_update_folio, and all
possible callers of them are:

.write_end -> nfs_update_folio
.page_mkwrite -> nfs_update_folio

- nfs_wb_folio_cancel

.invalidate_folio -> nfs_wb_folio_cancel

Also, seeing from the swap side, swap_rw is now the only interface calling
into fs, the offset info is always in iocb.ki_pos now.

So we can remove all these folio_file_pos call safely.

Signed-off-by: Kairui Song <kasong@tencent.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: linux-nfs@vger.kernel.org
---
fs/nfs/file.c | 2 +-
fs/nfs/nfstrace.h | 4 ++--
fs/nfs/write.c | 6 +++---
3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 407c6e15afe2..02741c32e114 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -588,7 +588,7 @@ static vm_fault_t nfs_vm_page_mkwrite(struct vm_fault *vmf)

dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%pD2(%lu), offset %lld)\n",
filp, filp->f_mapping->host->i_ino,
- (long long)folio_file_pos(folio));
+ (long long)folio_pos(folio));

sb_start_pagefault(inode->i_sb);

diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h
index afedb449b54f..d249741452e1 100644
--- a/fs/nfs/nfstrace.h
+++ b/fs/nfs/nfstrace.h
@@ -960,7 +960,7 @@ DECLARE_EVENT_CLASS(nfs_folio_event,
__entry->fileid = nfsi->fileid;
__entry->fhandle = nfs_fhandle_hash(&nfsi->fh);
__entry->version = inode_peek_iversion_raw(inode);
- __entry->offset = folio_file_pos(folio);
+ __entry->offset = folio_pos(folio);
__entry->count = nfs_folio_length(folio);
),

@@ -1008,7 +1008,7 @@ DECLARE_EVENT_CLASS(nfs_folio_event_done,
__entry->fileid = nfsi->fileid;
__entry->fhandle = nfs_fhandle_hash(&nfsi->fh);
__entry->version = inode_peek_iversion_raw(inode);
- __entry->offset = folio_file_pos(folio);
+ __entry->offset = folio_pos(folio);
__entry->count = nfs_folio_length(folio);
__entry->ret = ret;
),
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 5de85d725fb9..fc782d889449 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -281,7 +281,7 @@ static void nfs_grow_file(struct folio *folio, unsigned int offset,
end_index = ((i_size - 1) >> folio_shift(folio)) << folio_order(folio);
if (i_size > 0 && folio_index(folio) < end_index)
goto out;
- end = folio_file_pos(folio) + (loff_t)offset + (loff_t)count;
+ end = folio_pos(folio) + (loff_t)offset + (loff_t)count;
if (i_size >= end)
goto out;
trace_nfs_size_grow(inode, end);
@@ -1362,7 +1362,7 @@ int nfs_update_folio(struct file *file, struct folio *folio,
nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);

dprintk("NFS: nfs_update_folio(%pD2 %d@%lld)\n", file, count,
- (long long)(folio_file_pos(folio) + offset));
+ (long long)(folio_pos(folio) + offset));

if (!count)
goto out;
@@ -2073,7 +2073,7 @@ int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio)
*/
int nfs_wb_folio(struct inode *inode, struct folio *folio)
{
- loff_t range_start = folio_file_pos(folio);
+ loff_t range_start = folio_pos(folio);
loff_t range_end = range_start + (loff_t)folio_size(folio) - 1;
struct writeback_control wbc = {
.sync_mode = WB_SYNC_ALL,
--
2.45.0