From: Kairui Song <kasong@tencent.com>
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 is never exposed to
nfs and it can't be a swap cache page here, so just drop it and
use folio_pos instead.
Signed-off-by: Kairui Song <kasong@tencent.com>
---
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,
--
2.44.0On Tue, Apr 30, 2024 at 03:11:34AM +0800, Kairui Song wrote:
> +++ 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));
Yes, we can't call page_mkwrite() on a swapcache page.
> +++ 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);
These two I don't know about.
> +++ 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;
This one concerns me. Are we sure we can't call nfs_grow_file()
for a swapfile?
> @@ -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;
Likewise here. Are we absolutely certain that swap I/O can't call this
function?
On Tue, Apr 30, 2024 at 3:21 AM Matthew Wilcox <willy@infradead.org> wrote:
>
> On Tue, Apr 30, 2024 at 03:11:34AM +0800, Kairui Song wrote:
> > +++ 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));
>
> Yes, we can't call page_mkwrite() on a swapcache page.
>
> > +++ 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);
>
> These two I don't know about.
I can add a more detailed call chain for this in the commit message to
make it look more convincing.
> > +++ 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;
>
> This one concerns me. Are we sure we can't call nfs_grow_file()
> for a swapfile?
Right, I did a audit of the code, all callers of nfs_grow_file are listed below:
.write_end -> nfs_write_end -> nfs_update_folio -> nfs_writepage_setup
-> nfs_grow_file
.page_mkwrite -> nfs_vm_page_mkwrite -> nfs_update_folio ->
nfs_writepage_setup -> nfs_grow_file
>
> > @@ -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;
>
> Likewise here. Are we absolutely certain that swap I/O can't call this
> function?
Similar above:
.release_folio -> nfs_release_folio -> nfs_wb_folio
.launder_folio -> nfs_launder_folio -> nfs_wb_folio
.write_begin -> nfs_write_begin -> nfs_read_folio -> nfs_wb_folio
.read_folio -> nfs_read_folio -> nfs_wb_folio
nfs_update_folio (listed above) -> nfs_writepage_setup ->
nfs_setup_write_request -> nfs_try_to_update_request -> nfs_wb_folio--
.write_begin -> nfs_write_begin -> nfs_flush_incompatible -> nfs_wb_folio
.page_mkwrite -> nfs_vm_page_mkwrite -> nfs_flush_incompatible -> nfs_wb_folio
And nothing from the swap mapping side can call into fs, except
swap_rw, none of the helpers are called by that.
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