| Message ID | 20240429191138.34123-1-ryncsn@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/swap: clean up and optimize swap cache index | expand |
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. > +++ 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.
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,