diff mbox series

[11/12] shmem: add file length arg in shmem_get_folio() path

Message ID 20240515055719.32577-12-da.gomez@samsung.com (mailing list archive)
State Accepted, archived
Headers show
Series [01/12] splice: don't check for uptodate if partially uptodate is impl | expand

Commit Message

Daniel Gomez May 15, 2024, 5:57 a.m. UTC
In preparation for large folio in the write and fallocate paths, add
file length argument in shmem_get_folio() path to be able to calculate
the folio order based on the file size. Use of order-0 (PAGE_SIZE) for
read, page cache read, and vm fault.

This enables high order folios in the write and fallocate path once the
folio order is calculated based on the length.

Signed-off-by: Daniel Gomez <da.gomez@samsung.com>
---
 fs/xfs/scrub/xfile.c     |  6 +++---
 fs/xfs/xfs_buf_mem.c     |  3 ++-
 include/linux/shmem_fs.h |  2 +-
 mm/khugepaged.c          |  3 ++-
 mm/shmem.c               | 35 ++++++++++++++++++++---------------
 mm/userfaultfd.c         |  2 +-
 6 files changed, 29 insertions(+), 22 deletions(-)

Comments

kernel test robot May 15, 2024, 5:47 p.m. UTC | #1
Hi Daniel,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on xfs-linux/for-next brauner-vfs/vfs.all linus/master v6.9 next-20240515]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Daniel-Gomez/splice-don-t-check-for-uptodate-if-partially-uptodate-is-impl/20240515-135925
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20240515055719.32577-12-da.gomez%40samsung.com
patch subject: [PATCH 11/12] shmem: add file length arg in shmem_get_folio() path
config: openrisc-defconfig (https://download.01.org/0day-ci/archive/20240516/202405160144.a9ad9CX5-lkp@intel.com/config)
compiler: or1k-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240516/202405160144.a9ad9CX5-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202405160144.a9ad9CX5-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> mm/shmem.c:2382: warning: Function parameter or struct member 'len' not described in 'shmem_get_folio'


vim +2382 mm/shmem.c

^1da177e4c3f41 Linus Torvalds          2005-04-16  2356  
d7468609ee0f90 Christoph Hellwig       2024-02-19  2357  /**
d7468609ee0f90 Christoph Hellwig       2024-02-19  2358   * shmem_get_folio - find, and lock a shmem folio.
d7468609ee0f90 Christoph Hellwig       2024-02-19  2359   * @inode:	inode to search
d7468609ee0f90 Christoph Hellwig       2024-02-19  2360   * @index:	the page index.
d7468609ee0f90 Christoph Hellwig       2024-02-19  2361   * @foliop:	pointer to the folio if found
d7468609ee0f90 Christoph Hellwig       2024-02-19  2362   * @sgp:	SGP_* flags to control behavior
d7468609ee0f90 Christoph Hellwig       2024-02-19  2363   *
d7468609ee0f90 Christoph Hellwig       2024-02-19  2364   * Looks up the page cache entry at @inode & @index.  If a folio is
d7468609ee0f90 Christoph Hellwig       2024-02-19  2365   * present, it is returned locked with an increased refcount.
d7468609ee0f90 Christoph Hellwig       2024-02-19  2366   *
9d8b36744935f8 Christoph Hellwig       2024-02-19  2367   * If the caller modifies data in the folio, it must call folio_mark_dirty()
9d8b36744935f8 Christoph Hellwig       2024-02-19  2368   * before unlocking the folio to ensure that the folio is not reclaimed.
9d8b36744935f8 Christoph Hellwig       2024-02-19  2369   * There is no need to reserve space before calling folio_mark_dirty().
9d8b36744935f8 Christoph Hellwig       2024-02-19  2370   *
d7468609ee0f90 Christoph Hellwig       2024-02-19  2371   * When no folio is found, the behavior depends on @sgp:
8d4dd9d741c330 Akira Yokosawa          2024-02-27  2372   *  - for SGP_READ, *@foliop is %NULL and 0 is returned
8d4dd9d741c330 Akira Yokosawa          2024-02-27  2373   *  - for SGP_NOALLOC, *@foliop is %NULL and -ENOENT is returned
d7468609ee0f90 Christoph Hellwig       2024-02-19  2374   *  - for all other flags a new folio is allocated, inserted into the
d7468609ee0f90 Christoph Hellwig       2024-02-19  2375   *    page cache and returned locked in @foliop.
d7468609ee0f90 Christoph Hellwig       2024-02-19  2376   *
d7468609ee0f90 Christoph Hellwig       2024-02-19  2377   * Context: May sleep.
d7468609ee0f90 Christoph Hellwig       2024-02-19  2378   * Return: 0 if successful, else a negative error code.
d7468609ee0f90 Christoph Hellwig       2024-02-19  2379   */
4e1fc793ad9892 Matthew Wilcox (Oracle  2022-09-02  2380) int shmem_get_folio(struct inode *inode, pgoff_t index, struct folio **foliop,
02efe2fbe45ffd Daniel Gomez            2024-05-15  2381  		enum sgp_type sgp, size_t len)
4e1fc793ad9892 Matthew Wilcox (Oracle  2022-09-02 @2382) {
4e1fc793ad9892 Matthew Wilcox (Oracle  2022-09-02  2383) 	return shmem_get_folio_gfp(inode, index, foliop, sgp,
02efe2fbe45ffd Daniel Gomez            2024-05-15  2384  			mapping_gfp_mask(inode->i_mapping), NULL, NULL, len);
4e1fc793ad9892 Matthew Wilcox (Oracle  2022-09-02  2385) }
d7468609ee0f90 Christoph Hellwig       2024-02-19  2386  EXPORT_SYMBOL_GPL(shmem_get_folio);
4e1fc793ad9892 Matthew Wilcox (Oracle  2022-09-02  2387)
Darrick J. Wong May 17, 2024, 4:17 p.m. UTC | #2
On Wed, May 15, 2024 at 05:57:36AM +0000, Daniel Gomez wrote:
> In preparation for large folio in the write and fallocate paths, add
> file length argument in shmem_get_folio() path to be able to calculate
> the folio order based on the file size. Use of order-0 (PAGE_SIZE) for
> read, page cache read, and vm fault.
> 
> This enables high order folios in the write and fallocate path once the
> folio order is calculated based on the length.
> 
> Signed-off-by: Daniel Gomez <da.gomez@samsung.com>
> ---
>  fs/xfs/scrub/xfile.c     |  6 +++---
>  fs/xfs/xfs_buf_mem.c     |  3 ++-
>  include/linux/shmem_fs.h |  2 +-
>  mm/khugepaged.c          |  3 ++-
>  mm/shmem.c               | 35 ++++++++++++++++++++---------------
>  mm/userfaultfd.c         |  2 +-
>  6 files changed, 29 insertions(+), 22 deletions(-)
> 
> diff --git a/fs/xfs/scrub/xfile.c b/fs/xfs/scrub/xfile.c
> index 8cdd863db585..4905f5e4cb5d 100644
> --- a/fs/xfs/scrub/xfile.c
> +++ b/fs/xfs/scrub/xfile.c
> @@ -127,7 +127,7 @@ xfile_load(
>  		unsigned int	offset;
>  
>  		if (shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
> -				SGP_READ) < 0)
> +				SGP_READ, PAGE_SIZE) < 0)

I suppose I /did/ say during LSFMM that for the current users of xfile.c
and xfs_buf_mem.c the order of the folio being returned doesn't really
matter, but why wouldn't the last argument here be "roundup_64(count,
PAGE_SIZE)" ?  Shouldn't we at least hint to the page cache about the
folio order that we actually want instead of limiting it to order-0?

(Also it seems a little odd to me that the @index is in units of pgoff_t
but @len is in bytes.)

>  			break;
>  		if (!folio) {
>  			/*
> @@ -197,7 +197,7 @@ xfile_store(
>  		unsigned int	offset;
>  
>  		if (shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
> -				SGP_CACHE) < 0)
> +				SGP_CACHE, PAGE_SIZE) < 0)
>  			break;
>  		if (filemap_check_wb_err(inode->i_mapping, 0)) {
>  			folio_unlock(folio);
> @@ -268,7 +268,7 @@ xfile_get_folio(
>  
>  	pflags = memalloc_nofs_save();
>  	error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
> -			(flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ);
> +			(flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ, PAGE_SIZE);
>  	memalloc_nofs_restore(pflags);
>  	if (error)
>  		return ERR_PTR(error);
> diff --git a/fs/xfs/xfs_buf_mem.c b/fs/xfs/xfs_buf_mem.c
> index 9bb2d24de709..784c81d35a1f 100644
> --- a/fs/xfs/xfs_buf_mem.c
> +++ b/fs/xfs/xfs_buf_mem.c
> @@ -149,7 +149,8 @@ xmbuf_map_page(
>  		return -ENOMEM;
>  	}
>  
> -	error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio, SGP_CACHE);
> +	error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio, SGP_CACHE,
> +				PAGE_SIZE);

This is ok unless someone wants to use a different XMBUF_BLOCKSIZE.

--D

>  	if (error)
>  		return error;
>  
> diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
> index 3fb18f7eb73e..bc59b4a00228 100644
> --- a/include/linux/shmem_fs.h
> +++ b/include/linux/shmem_fs.h
> @@ -142,7 +142,7 @@ enum sgp_type {
>  };
>  
>  int shmem_get_folio(struct inode *inode, pgoff_t index, struct folio **foliop,
> -		enum sgp_type sgp);
> +		enum sgp_type sgp, size_t len);
>  struct folio *shmem_read_folio_gfp(struct address_space *mapping,
>  		pgoff_t index, gfp_t gfp);
>  
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 38830174608f..947770ded68c 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -1863,7 +1863,8 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr,
>  				xas_unlock_irq(&xas);
>  				/* swap in or instantiate fallocated page */
>  				if (shmem_get_folio(mapping->host, index,
> -						&folio, SGP_NOALLOC)) {
> +						    &folio, SGP_NOALLOC,
> +						    PAGE_SIZE)) {
>  					result = SCAN_FAIL;
>  					goto xa_unlocked;
>  				}
> diff --git a/mm/shmem.c b/mm/shmem.c
> index d531018ffece..fcd2c9befe19 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -1134,7 +1134,7 @@ static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index)
>  	 * (although in some cases this is just a waste of time).
>  	 */
>  	folio = NULL;
> -	shmem_get_folio(inode, index, &folio, SGP_READ);
> +	shmem_get_folio(inode, index, &folio, SGP_READ, PAGE_SIZE);
>  	return folio;
>  }
>  
> @@ -1844,7 +1844,7 @@ static struct folio *shmem_alloc_folio(gfp_t gfp, struct shmem_inode_info *info,
>  
>  static struct folio *shmem_alloc_and_add_folio(gfp_t gfp,
>  		struct inode *inode, pgoff_t index,
> -		struct mm_struct *fault_mm, bool huge)
> +		struct mm_struct *fault_mm, bool huge, size_t len)
>  {
>  	struct address_space *mapping = inode->i_mapping;
>  	struct shmem_inode_info *info = SHMEM_I(inode);
> @@ -2173,7 +2173,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index,
>   */
>  static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
>  		struct folio **foliop, enum sgp_type sgp, gfp_t gfp,
> -		struct vm_fault *vmf, vm_fault_t *fault_type)
> +		struct vm_fault *vmf, vm_fault_t *fault_type, size_t len)
>  {
>  	struct vm_area_struct *vma = vmf ? vmf->vma : NULL;
>  	struct mm_struct *fault_mm;
> @@ -2258,7 +2258,7 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
>  		huge_gfp = vma_thp_gfp_mask(vma);
>  		huge_gfp = limit_gfp_mask(huge_gfp, gfp);
>  		folio = shmem_alloc_and_add_folio(huge_gfp,
> -				inode, index, fault_mm, true);
> +				inode, index, fault_mm, true, len);
>  		if (!IS_ERR(folio)) {
>  			count_vm_event(THP_FILE_ALLOC);
>  			goto alloced;
> @@ -2267,7 +2267,8 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
>  			goto repeat;
>  	}
>  
> -	folio = shmem_alloc_and_add_folio(gfp, inode, index, fault_mm, false);
> +	folio = shmem_alloc_and_add_folio(gfp, inode, index, fault_mm, false,
> +					  len);
>  	if (IS_ERR(folio)) {
>  		error = PTR_ERR(folio);
>  		if (error == -EEXIST)
> @@ -2377,10 +2378,10 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
>   * Return: 0 if successful, else a negative error code.
>   */
>  int shmem_get_folio(struct inode *inode, pgoff_t index, struct folio **foliop,
> -		enum sgp_type sgp)
> +		enum sgp_type sgp, size_t len)
>  {
>  	return shmem_get_folio_gfp(inode, index, foliop, sgp,
> -			mapping_gfp_mask(inode->i_mapping), NULL, NULL);
> +			mapping_gfp_mask(inode->i_mapping), NULL, NULL, len);
>  }
>  EXPORT_SYMBOL_GPL(shmem_get_folio);
>  
> @@ -2475,7 +2476,7 @@ static vm_fault_t shmem_fault(struct vm_fault *vmf)
>  
>  	WARN_ON_ONCE(vmf->page != NULL);
>  	err = shmem_get_folio_gfp(inode, vmf->pgoff, &folio, SGP_CACHE,
> -				  gfp, vmf, &ret);
> +				  gfp, vmf, &ret, PAGE_SIZE);
>  	if (err)
>  		return vmf_error(err);
>  	if (folio) {
> @@ -2954,6 +2955,9 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
>  	struct folio *folio;
>  	int ret = 0;
>  
> +	if (!mapping_large_folio_support(mapping))
> +		len = min_t(size_t, len, PAGE_SIZE - offset_in_page(pos));
> +
>  	/* i_rwsem is held by caller */
>  	if (unlikely(info->seals & (F_SEAL_GROW |
>  				   F_SEAL_WRITE | F_SEAL_FUTURE_WRITE))) {
> @@ -2963,7 +2967,7 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
>  			return -EPERM;
>  	}
>  
> -	ret = shmem_get_folio(inode, index, &folio, SGP_WRITE);
> +	ret = shmem_get_folio(inode, index, &folio, SGP_WRITE, len);
>  	if (ret)
>  		return ret;
>  
> @@ -3083,7 +3087,7 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
>  				break;
>  		}
>  
> -		error = shmem_get_folio(inode, index, &folio, SGP_READ);
> +		error = shmem_get_folio(inode, index, &folio, SGP_READ, PAGE_SIZE);
>  		if (error) {
>  			if (error == -EINVAL)
>  				error = 0;
> @@ -3260,7 +3264,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
>  			break;
>  
>  		error = shmem_get_folio(inode, *ppos / PAGE_SIZE, &folio,
> -					SGP_READ);
> +					SGP_READ, PAGE_SIZE);
>  		if (error) {
>  			if (error == -EINVAL)
>  				error = 0;
> @@ -3469,7 +3473,8 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
>  			error = -ENOMEM;
>  		else
>  			error = shmem_get_folio(inode, index, &folio,
> -						SGP_FALLOC);
> +						SGP_FALLOC,
> +						(end - index) << PAGE_SHIFT);
>  		if (error) {
>  			info->fallocend = undo_fallocend;
>  			/* Remove the !uptodate folios we added */
> @@ -3822,7 +3827,7 @@ static int shmem_symlink(struct mnt_idmap *idmap, struct inode *dir,
>  	} else {
>  		inode_nohighmem(inode);
>  		inode->i_mapping->a_ops = &shmem_aops;
> -		error = shmem_get_folio(inode, 0, &folio, SGP_WRITE);
> +		error = shmem_get_folio(inode, 0, &folio, SGP_WRITE, PAGE_SIZE);
>  		if (error)
>  			goto out_remove_offset;
>  		inode->i_op = &shmem_symlink_inode_operations;
> @@ -3868,7 +3873,7 @@ static const char *shmem_get_link(struct dentry *dentry, struct inode *inode,
>  			return ERR_PTR(-ECHILD);
>  		}
>  	} else {
> -		error = shmem_get_folio(inode, 0, &folio, SGP_READ);
> +		error = shmem_get_folio(inode, 0, &folio, SGP_READ, PAGE_SIZE);
>  		if (error)
>  			return ERR_PTR(error);
>  		if (!folio)
> @@ -5255,7 +5260,7 @@ struct folio *shmem_read_folio_gfp(struct address_space *mapping,
>  	int error;
>  
>  	error = shmem_get_folio_gfp(inode, index, &folio, SGP_CACHE,
> -				    gfp, NULL, NULL);
> +				    gfp, NULL, NULL, PAGE_SIZE);
>  	if (error)
>  		return ERR_PTR(error);
>  
> diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
> index 3c3539c573e7..540a0c2d4325 100644
> --- a/mm/userfaultfd.c
> +++ b/mm/userfaultfd.c
> @@ -359,7 +359,7 @@ static int mfill_atomic_pte_continue(pmd_t *dst_pmd,
>  	struct page *page;
>  	int ret;
>  
> -	ret = shmem_get_folio(inode, pgoff, &folio, SGP_NOALLOC);
> +	ret = shmem_get_folio(inode, pgoff, &folio, SGP_NOALLOC, PAGE_SIZE);
>  	/* Our caller expects us to return -EFAULT if we failed to find folio */
>  	if (ret == -ENOENT)
>  		ret = -EFAULT;
> -- 
> 2.43.0
>
Daniel Gomez May 21, 2024, 11:38 a.m. UTC | #3
On Fri, May 17, 2024 at 09:17:41AM -0700, Darrick J. Wong wrote:
> On Wed, May 15, 2024 at 05:57:36AM +0000, Daniel Gomez wrote:
> > In preparation for large folio in the write and fallocate paths, add
> > file length argument in shmem_get_folio() path to be able to calculate
> > the folio order based on the file size. Use of order-0 (PAGE_SIZE) for
> > read, page cache read, and vm fault.
> > 
> > This enables high order folios in the write and fallocate path once the
> > folio order is calculated based on the length.
> > 
> > Signed-off-by: Daniel Gomez <da.gomez@samsung.com>
> > ---
> >  fs/xfs/scrub/xfile.c     |  6 +++---
> >  fs/xfs/xfs_buf_mem.c     |  3 ++-
> >  include/linux/shmem_fs.h |  2 +-
> >  mm/khugepaged.c          |  3 ++-
> >  mm/shmem.c               | 35 ++++++++++++++++++++---------------
> >  mm/userfaultfd.c         |  2 +-
> >  6 files changed, 29 insertions(+), 22 deletions(-)
> > 
> > diff --git a/fs/xfs/scrub/xfile.c b/fs/xfs/scrub/xfile.c
> > index 8cdd863db585..4905f5e4cb5d 100644
> > --- a/fs/xfs/scrub/xfile.c
> > +++ b/fs/xfs/scrub/xfile.c
> > @@ -127,7 +127,7 @@ xfile_load(
> >  		unsigned int	offset;
> >  
> >  		if (shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
> > -				SGP_READ) < 0)
> > +				SGP_READ, PAGE_SIZE) < 0)
> 
> I suppose I /did/ say during LSFMM that for the current users of xfile.c
> and xfs_buf_mem.c the order of the folio being returned doesn't really
I not sure if I understood you well. Could you please elaborate on this?

> matter, but why wouldn't the last argument here be "roundup_64(count,
> PAGE_SIZE)" ?  Shouldn't we at least hint to the page cache about the
> folio order that we actually want instead of limiting it to order-0?

For v2, I'll include your suggestions. I think we can also enable large folios
in xfile_get_folio(), please check below:

diff --git a/fs/xfs/scrub/xfile.c b/fs/xfs/scrub/xfile.c
index 8cdd863db585..df8b495b4939 100644
--- a/fs/xfs/scrub/xfile.c
+++ b/fs/xfs/scrub/xfile.c
@@ -127,7 +127,7 @@ xfile_load(
                unsigned int    offset;

                if (shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
-                               SGP_READ) < 0)
+                               SGP_READ, roundup_64(count, PAGE_SIZE)) < 0)
                        break;
                if (!folio) {
                        /*
@@ -197,7 +197,7 @@ xfile_store(
                unsigned int    offset;

                if (shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
-                               SGP_CACHE) < 0)
+                               SGP_CACHE, roundup_64(count, PAGE_SIZE)) < 0)
                        break;
                if (filemap_check_wb_err(inode->i_mapping, 0)) {
                        folio_unlock(folio);
@@ -268,7 +268,8 @@ xfile_get_folio(

        pflags = memalloc_nofs_save();
        error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
-                       (flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ);
+                       (flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ,
+                       roundup_64(i_size_read(inode), PAGE_SIZE));
        memalloc_nofs_restore(pflags);
        if (error)
                return ERR_PTR(error);

> 
> (Also it seems a little odd to me that the @index is in units of pgoff_t
> but @len is in bytes.)

I extended the shmem_get_folio() with @len to calculate folio order based on
size (bytes). This is sent to ilog2() although I'm planning to use get_order()
instead (after fixing the issues mentioned during the discussion). @index is
used for __ffs() (same as in filemap).

Would you use lofft for @len instead? Or what's your suggestion?

Thanks,
Daniel

> 
> >  			break;
> >  		if (!folio) {
> >  			/*
> > @@ -197,7 +197,7 @@ xfile_store(
> >  		unsigned int	offset;
> >  
> >  		if (shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
> > -				SGP_CACHE) < 0)
> > +				SGP_CACHE, PAGE_SIZE) < 0)
> >  			break;
> >  		if (filemap_check_wb_err(inode->i_mapping, 0)) {
> >  			folio_unlock(folio);
> > @@ -268,7 +268,7 @@ xfile_get_folio(
> >  
> >  	pflags = memalloc_nofs_save();
> >  	error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
> > -			(flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ);
> > +			(flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ, PAGE_SIZE);
> >  	memalloc_nofs_restore(pflags);
> >  	if (error)
> >  		return ERR_PTR(error);
> > diff --git a/fs/xfs/xfs_buf_mem.c b/fs/xfs/xfs_buf_mem.c
> > index 9bb2d24de709..784c81d35a1f 100644
> > --- a/fs/xfs/xfs_buf_mem.c
> > +++ b/fs/xfs/xfs_buf_mem.c
> > @@ -149,7 +149,8 @@ xmbuf_map_page(
> >  		return -ENOMEM;
> >  	}
> >  
> > -	error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio, SGP_CACHE);
> > +	error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio, SGP_CACHE,
> > +				PAGE_SIZE);
> 
> This is ok unless someone wants to use a different XMBUF_BLOCKSIZE.
> 
> --D
> 
> >  	if (error)
> >  		return error;
> >  
> > diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
> > index 3fb18f7eb73e..bc59b4a00228 100644
> > --- a/include/linux/shmem_fs.h
> > +++ b/include/linux/shmem_fs.h
> > @@ -142,7 +142,7 @@ enum sgp_type {
> >  };
> >  
> >  int shmem_get_folio(struct inode *inode, pgoff_t index, struct folio **foliop,
> > -		enum sgp_type sgp);
> > +		enum sgp_type sgp, size_t len);
> >  struct folio *shmem_read_folio_gfp(struct address_space *mapping,
> >  		pgoff_t index, gfp_t gfp);
> >  
> > diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> > index 38830174608f..947770ded68c 100644
> > --- a/mm/khugepaged.c
> > +++ b/mm/khugepaged.c
> > @@ -1863,7 +1863,8 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr,
> >  				xas_unlock_irq(&xas);
> >  				/* swap in or instantiate fallocated page */
> >  				if (shmem_get_folio(mapping->host, index,
> > -						&folio, SGP_NOALLOC)) {
> > +						    &folio, SGP_NOALLOC,
> > +						    PAGE_SIZE)) {
> >  					result = SCAN_FAIL;
> >  					goto xa_unlocked;
> >  				}
> > diff --git a/mm/shmem.c b/mm/shmem.c
> > index d531018ffece..fcd2c9befe19 100644
> > --- a/mm/shmem.c
> > +++ b/mm/shmem.c
> > @@ -1134,7 +1134,7 @@ static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index)
> >  	 * (although in some cases this is just a waste of time).
> >  	 */
> >  	folio = NULL;
> > -	shmem_get_folio(inode, index, &folio, SGP_READ);
> > +	shmem_get_folio(inode, index, &folio, SGP_READ, PAGE_SIZE);
> >  	return folio;
> >  }
> >  
> > @@ -1844,7 +1844,7 @@ static struct folio *shmem_alloc_folio(gfp_t gfp, struct shmem_inode_info *info,
> >  
> >  static struct folio *shmem_alloc_and_add_folio(gfp_t gfp,
> >  		struct inode *inode, pgoff_t index,
> > -		struct mm_struct *fault_mm, bool huge)
> > +		struct mm_struct *fault_mm, bool huge, size_t len)
> >  {
> >  	struct address_space *mapping = inode->i_mapping;
> >  	struct shmem_inode_info *info = SHMEM_I(inode);
> > @@ -2173,7 +2173,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index,
> >   */
> >  static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
> >  		struct folio **foliop, enum sgp_type sgp, gfp_t gfp,
> > -		struct vm_fault *vmf, vm_fault_t *fault_type)
> > +		struct vm_fault *vmf, vm_fault_t *fault_type, size_t len)
> >  {
> >  	struct vm_area_struct *vma = vmf ? vmf->vma : NULL;
> >  	struct mm_struct *fault_mm;
> > @@ -2258,7 +2258,7 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
> >  		huge_gfp = vma_thp_gfp_mask(vma);
> >  		huge_gfp = limit_gfp_mask(huge_gfp, gfp);
> >  		folio = shmem_alloc_and_add_folio(huge_gfp,
> > -				inode, index, fault_mm, true);
> > +				inode, index, fault_mm, true, len);
> >  		if (!IS_ERR(folio)) {
> >  			count_vm_event(THP_FILE_ALLOC);
> >  			goto alloced;
> > @@ -2267,7 +2267,8 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
> >  			goto repeat;
> >  	}
> >  
> > -	folio = shmem_alloc_and_add_folio(gfp, inode, index, fault_mm, false);
> > +	folio = shmem_alloc_and_add_folio(gfp, inode, index, fault_mm, false,
> > +					  len);
> >  	if (IS_ERR(folio)) {
> >  		error = PTR_ERR(folio);
> >  		if (error == -EEXIST)
> > @@ -2377,10 +2378,10 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
> >   * Return: 0 if successful, else a negative error code.
> >   */
> >  int shmem_get_folio(struct inode *inode, pgoff_t index, struct folio **foliop,
> > -		enum sgp_type sgp)
> > +		enum sgp_type sgp, size_t len)
> >  {
> >  	return shmem_get_folio_gfp(inode, index, foliop, sgp,
> > -			mapping_gfp_mask(inode->i_mapping), NULL, NULL);
> > +			mapping_gfp_mask(inode->i_mapping), NULL, NULL, len);
> >  }
> >  EXPORT_SYMBOL_GPL(shmem_get_folio);
> >  
> > @@ -2475,7 +2476,7 @@ static vm_fault_t shmem_fault(struct vm_fault *vmf)
> >  
> >  	WARN_ON_ONCE(vmf->page != NULL);
> >  	err = shmem_get_folio_gfp(inode, vmf->pgoff, &folio, SGP_CACHE,
> > -				  gfp, vmf, &ret);
> > +				  gfp, vmf, &ret, PAGE_SIZE);
> >  	if (err)
> >  		return vmf_error(err);
> >  	if (folio) {
> > @@ -2954,6 +2955,9 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
> >  	struct folio *folio;
> >  	int ret = 0;
> >  
> > +	if (!mapping_large_folio_support(mapping))
> > +		len = min_t(size_t, len, PAGE_SIZE - offset_in_page(pos));
> > +
> >  	/* i_rwsem is held by caller */
> >  	if (unlikely(info->seals & (F_SEAL_GROW |
> >  				   F_SEAL_WRITE | F_SEAL_FUTURE_WRITE))) {
> > @@ -2963,7 +2967,7 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
> >  			return -EPERM;
> >  	}
> >  
> > -	ret = shmem_get_folio(inode, index, &folio, SGP_WRITE);
> > +	ret = shmem_get_folio(inode, index, &folio, SGP_WRITE, len);
> >  	if (ret)
> >  		return ret;
> >  
> > @@ -3083,7 +3087,7 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
> >  				break;
> >  		}
> >  
> > -		error = shmem_get_folio(inode, index, &folio, SGP_READ);
> > +		error = shmem_get_folio(inode, index, &folio, SGP_READ, PAGE_SIZE);
> >  		if (error) {
> >  			if (error == -EINVAL)
> >  				error = 0;
> > @@ -3260,7 +3264,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
> >  			break;
> >  
> >  		error = shmem_get_folio(inode, *ppos / PAGE_SIZE, &folio,
> > -					SGP_READ);
> > +					SGP_READ, PAGE_SIZE);
> >  		if (error) {
> >  			if (error == -EINVAL)
> >  				error = 0;
> > @@ -3469,7 +3473,8 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
> >  			error = -ENOMEM;
> >  		else
> >  			error = shmem_get_folio(inode, index, &folio,
> > -						SGP_FALLOC);
> > +						SGP_FALLOC,
> > +						(end - index) << PAGE_SHIFT);
> >  		if (error) {
> >  			info->fallocend = undo_fallocend;
> >  			/* Remove the !uptodate folios we added */
> > @@ -3822,7 +3827,7 @@ static int shmem_symlink(struct mnt_idmap *idmap, struct inode *dir,
> >  	} else {
> >  		inode_nohighmem(inode);
> >  		inode->i_mapping->a_ops = &shmem_aops;
> > -		error = shmem_get_folio(inode, 0, &folio, SGP_WRITE);
> > +		error = shmem_get_folio(inode, 0, &folio, SGP_WRITE, PAGE_SIZE);
> >  		if (error)
> >  			goto out_remove_offset;
> >  		inode->i_op = &shmem_symlink_inode_operations;
> > @@ -3868,7 +3873,7 @@ static const char *shmem_get_link(struct dentry *dentry, struct inode *inode,
> >  			return ERR_PTR(-ECHILD);
> >  		}
> >  	} else {
> > -		error = shmem_get_folio(inode, 0, &folio, SGP_READ);
> > +		error = shmem_get_folio(inode, 0, &folio, SGP_READ, PAGE_SIZE);
> >  		if (error)
> >  			return ERR_PTR(error);
> >  		if (!folio)
> > @@ -5255,7 +5260,7 @@ struct folio *shmem_read_folio_gfp(struct address_space *mapping,
> >  	int error;
> >  
> >  	error = shmem_get_folio_gfp(inode, index, &folio, SGP_CACHE,
> > -				    gfp, NULL, NULL);
> > +				    gfp, NULL, NULL, PAGE_SIZE);
> >  	if (error)
> >  		return ERR_PTR(error);
> >  
> > diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
> > index 3c3539c573e7..540a0c2d4325 100644
> > --- a/mm/userfaultfd.c
> > +++ b/mm/userfaultfd.c
> > @@ -359,7 +359,7 @@ static int mfill_atomic_pte_continue(pmd_t *dst_pmd,
> >  	struct page *page;
> >  	int ret;
> >  
> > -	ret = shmem_get_folio(inode, pgoff, &folio, SGP_NOALLOC);
> > +	ret = shmem_get_folio(inode, pgoff, &folio, SGP_NOALLOC, PAGE_SIZE);
> >  	/* Our caller expects us to return -EFAULT if we failed to find folio */
> >  	if (ret == -ENOENT)
> >  		ret = -EFAULT;
> > -- 
> > 2.43.0
> >
Darrick J. Wong May 21, 2024, 4:36 p.m. UTC | #4
On Tue, May 21, 2024 at 11:38:33AM +0000, Daniel Gomez wrote:
> On Fri, May 17, 2024 at 09:17:41AM -0700, Darrick J. Wong wrote:
> > On Wed, May 15, 2024 at 05:57:36AM +0000, Daniel Gomez wrote:
> > > In preparation for large folio in the write and fallocate paths, add
> > > file length argument in shmem_get_folio() path to be able to calculate
> > > the folio order based on the file size. Use of order-0 (PAGE_SIZE) for
> > > read, page cache read, and vm fault.
> > > 
> > > This enables high order folios in the write and fallocate path once the
> > > folio order is calculated based on the length.
> > > 
> > > Signed-off-by: Daniel Gomez <da.gomez@samsung.com>
> > > ---
> > >  fs/xfs/scrub/xfile.c     |  6 +++---
> > >  fs/xfs/xfs_buf_mem.c     |  3 ++-
> > >  include/linux/shmem_fs.h |  2 +-
> > >  mm/khugepaged.c          |  3 ++-
> > >  mm/shmem.c               | 35 ++++++++++++++++++++---------------
> > >  mm/userfaultfd.c         |  2 +-
> > >  6 files changed, 29 insertions(+), 22 deletions(-)
> > > 
> > > diff --git a/fs/xfs/scrub/xfile.c b/fs/xfs/scrub/xfile.c
> > > index 8cdd863db585..4905f5e4cb5d 100644
> > > --- a/fs/xfs/scrub/xfile.c
> > > +++ b/fs/xfs/scrub/xfile.c
> > > @@ -127,7 +127,7 @@ xfile_load(
> > >  		unsigned int	offset;
> > >  
> > >  		if (shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
> > > -				SGP_READ) < 0)
> > > +				SGP_READ, PAGE_SIZE) < 0)
> > 
> > I suppose I /did/ say during LSFMM that for the current users of xfile.c
> > and xfs_buf_mem.c the order of the folio being returned doesn't really
> I not sure if I understood you well. Could you please elaborate on this?

Yes, I'll restate what I said in the session last week for those who
weren't there:

Currently, xfile.c and xfs_buf_mem.c are only used by online repair to
stage a recordset while rebuilding an ondisk btree index.  IOWs, they're
ephemeral, so we don't care or need to optimize folio sizing.  Some day
they might be adapted for longer-term usage though, so we might as well
try not to leave too many papercuts.

xfs_buf_mem.c creates in-memory btrees that mimic the ondisk btrees,
albeit with blocksize == PAGE_SIZE, regardless of the fs blocksize.
For this case we probably aren't ever going to care about large folios.

xfile.c is currently used to store fixed-size recordsets, names for
rebuilding directories, and name/value pairs for rebuilding xattr
structures.  Records aren't allowed to be larger than PAGE_SIZE, names
cannot be larger than MAXNAMELEN (255), and xattr values can't be larger
than 64k.

For that last case maybe it might be nice to get a large folio to reduce
processing overhead, but huge xattrs aren't that common.

> > matter, but why wouldn't the last argument here be "roundup_64(count,
> > PAGE_SIZE)" ?  Shouldn't we at least hint to the page cache about the
> > folio order that we actually want instead of limiting it to order-0?
> 
> For v2, I'll include your suggestions. I think we can also enable large folios
> in xfile_get_folio(), please check below:
> 
> diff --git a/fs/xfs/scrub/xfile.c b/fs/xfs/scrub/xfile.c
> index 8cdd863db585..df8b495b4939 100644
> --- a/fs/xfs/scrub/xfile.c
> +++ b/fs/xfs/scrub/xfile.c
> @@ -127,7 +127,7 @@ xfile_load(
>                 unsigned int    offset;
> 
>                 if (shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
> -                               SGP_READ) < 0)
> +                               SGP_READ, roundup_64(count, PAGE_SIZE)) < 0)
>                         break;
>                 if (!folio) {
>                         /*
> @@ -197,7 +197,7 @@ xfile_store(
>                 unsigned int    offset;
> 
>                 if (shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
> -                               SGP_CACHE) < 0)
> +                               SGP_CACHE, roundup_64(count, PAGE_SIZE)) < 0)
>                         break;
>                 if (filemap_check_wb_err(inode->i_mapping, 0)) {
>                         folio_unlock(folio);
> @@ -268,7 +268,8 @@ xfile_get_folio(
> 
>         pflags = memalloc_nofs_save();
>         error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
> -                       (flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ);
> +                       (flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ,
> +                       roundup_64(i_size_read(inode), PAGE_SIZE));

I'm not sure why you picked i_size_read here; the xfile could be several
gigabytes long.  xfile_get_folio want to look at a subset of the xfile,
not all of it.

roundup_64(len, PAGE_SIZE) perhaps?

Also, should the rounding be done inside the shmem code so that callers
don't have to know about that detail?

>         memalloc_nofs_restore(pflags);
>         if (error)
>                 return ERR_PTR(error);
> 
> > 
> > (Also it seems a little odd to me that the @index is in units of pgoff_t
> > but @len is in bytes.)
> 
> I extended the shmem_get_folio() with @len to calculate folio order based on
> size (bytes). This is sent to ilog2() although I'm planning to use get_order()
> instead (after fixing the issues mentioned during the discussion). @index is
> used for __ffs() (same as in filemap).
> 
> Would you use lofft for @len instead? Or what's your suggestion?

I was reacting to @index, not @len.  I might've shifted @index to
"loff_t pos" but looking at the existing callsites it doesn't seem worth
the churn.

--D

> Thanks,
> Daniel
> 
> > 
> > >  			break;
> > >  		if (!folio) {
> > >  			/*
> > > @@ -197,7 +197,7 @@ xfile_store(
> > >  		unsigned int	offset;
> > >  
> > >  		if (shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
> > > -				SGP_CACHE) < 0)
> > > +				SGP_CACHE, PAGE_SIZE) < 0)
> > >  			break;
> > >  		if (filemap_check_wb_err(inode->i_mapping, 0)) {
> > >  			folio_unlock(folio);
> > > @@ -268,7 +268,7 @@ xfile_get_folio(
> > >  
> > >  	pflags = memalloc_nofs_save();
> > >  	error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
> > > -			(flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ);
> > > +			(flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ, PAGE_SIZE);
> > >  	memalloc_nofs_restore(pflags);
> > >  	if (error)
> > >  		return ERR_PTR(error);
> > > diff --git a/fs/xfs/xfs_buf_mem.c b/fs/xfs/xfs_buf_mem.c
> > > index 9bb2d24de709..784c81d35a1f 100644
> > > --- a/fs/xfs/xfs_buf_mem.c
> > > +++ b/fs/xfs/xfs_buf_mem.c
> > > @@ -149,7 +149,8 @@ xmbuf_map_page(
> > >  		return -ENOMEM;
> > >  	}
> > >  
> > > -	error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio, SGP_CACHE);
> > > +	error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio, SGP_CACHE,
> > > +				PAGE_SIZE);
> > 
> > This is ok unless someone wants to use a different XMBUF_BLOCKSIZE.
> > 
> > --D
> > 
> > >  	if (error)
> > >  		return error;
> > >  
> > > diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
> > > index 3fb18f7eb73e..bc59b4a00228 100644
> > > --- a/include/linux/shmem_fs.h
> > > +++ b/include/linux/shmem_fs.h
> > > @@ -142,7 +142,7 @@ enum sgp_type {
> > >  };
> > >  
> > >  int shmem_get_folio(struct inode *inode, pgoff_t index, struct folio **foliop,
> > > -		enum sgp_type sgp);
> > > +		enum sgp_type sgp, size_t len);
> > >  struct folio *shmem_read_folio_gfp(struct address_space *mapping,
> > >  		pgoff_t index, gfp_t gfp);
> > >  
> > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> > > index 38830174608f..947770ded68c 100644
> > > --- a/mm/khugepaged.c
> > > +++ b/mm/khugepaged.c
> > > @@ -1863,7 +1863,8 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr,
> > >  				xas_unlock_irq(&xas);
> > >  				/* swap in or instantiate fallocated page */
> > >  				if (shmem_get_folio(mapping->host, index,
> > > -						&folio, SGP_NOALLOC)) {
> > > +						    &folio, SGP_NOALLOC,
> > > +						    PAGE_SIZE)) {
> > >  					result = SCAN_FAIL;
> > >  					goto xa_unlocked;
> > >  				}
> > > diff --git a/mm/shmem.c b/mm/shmem.c
> > > index d531018ffece..fcd2c9befe19 100644
> > > --- a/mm/shmem.c
> > > +++ b/mm/shmem.c
> > > @@ -1134,7 +1134,7 @@ static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index)
> > >  	 * (although in some cases this is just a waste of time).
> > >  	 */
> > >  	folio = NULL;
> > > -	shmem_get_folio(inode, index, &folio, SGP_READ);
> > > +	shmem_get_folio(inode, index, &folio, SGP_READ, PAGE_SIZE);
> > >  	return folio;
> > >  }
> > >  
> > > @@ -1844,7 +1844,7 @@ static struct folio *shmem_alloc_folio(gfp_t gfp, struct shmem_inode_info *info,
> > >  
> > >  static struct folio *shmem_alloc_and_add_folio(gfp_t gfp,
> > >  		struct inode *inode, pgoff_t index,
> > > -		struct mm_struct *fault_mm, bool huge)
> > > +		struct mm_struct *fault_mm, bool huge, size_t len)
> > >  {
> > >  	struct address_space *mapping = inode->i_mapping;
> > >  	struct shmem_inode_info *info = SHMEM_I(inode);
> > > @@ -2173,7 +2173,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index,
> > >   */
> > >  static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
> > >  		struct folio **foliop, enum sgp_type sgp, gfp_t gfp,
> > > -		struct vm_fault *vmf, vm_fault_t *fault_type)
> > > +		struct vm_fault *vmf, vm_fault_t *fault_type, size_t len)
> > >  {
> > >  	struct vm_area_struct *vma = vmf ? vmf->vma : NULL;
> > >  	struct mm_struct *fault_mm;
> > > @@ -2258,7 +2258,7 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
> > >  		huge_gfp = vma_thp_gfp_mask(vma);
> > >  		huge_gfp = limit_gfp_mask(huge_gfp, gfp);
> > >  		folio = shmem_alloc_and_add_folio(huge_gfp,
> > > -				inode, index, fault_mm, true);
> > > +				inode, index, fault_mm, true, len);
> > >  		if (!IS_ERR(folio)) {
> > >  			count_vm_event(THP_FILE_ALLOC);
> > >  			goto alloced;
> > > @@ -2267,7 +2267,8 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
> > >  			goto repeat;
> > >  	}
> > >  
> > > -	folio = shmem_alloc_and_add_folio(gfp, inode, index, fault_mm, false);
> > > +	folio = shmem_alloc_and_add_folio(gfp, inode, index, fault_mm, false,
> > > +					  len);
> > >  	if (IS_ERR(folio)) {
> > >  		error = PTR_ERR(folio);
> > >  		if (error == -EEXIST)
> > > @@ -2377,10 +2378,10 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
> > >   * Return: 0 if successful, else a negative error code.
> > >   */
> > >  int shmem_get_folio(struct inode *inode, pgoff_t index, struct folio **foliop,
> > > -		enum sgp_type sgp)
> > > +		enum sgp_type sgp, size_t len)
> > >  {
> > >  	return shmem_get_folio_gfp(inode, index, foliop, sgp,
> > > -			mapping_gfp_mask(inode->i_mapping), NULL, NULL);
> > > +			mapping_gfp_mask(inode->i_mapping), NULL, NULL, len);
> > >  }
> > >  EXPORT_SYMBOL_GPL(shmem_get_folio);
> > >  
> > > @@ -2475,7 +2476,7 @@ static vm_fault_t shmem_fault(struct vm_fault *vmf)
> > >  
> > >  	WARN_ON_ONCE(vmf->page != NULL);
> > >  	err = shmem_get_folio_gfp(inode, vmf->pgoff, &folio, SGP_CACHE,
> > > -				  gfp, vmf, &ret);
> > > +				  gfp, vmf, &ret, PAGE_SIZE);
> > >  	if (err)
> > >  		return vmf_error(err);
> > >  	if (folio) {
> > > @@ -2954,6 +2955,9 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
> > >  	struct folio *folio;
> > >  	int ret = 0;
> > >  
> > > +	if (!mapping_large_folio_support(mapping))
> > > +		len = min_t(size_t, len, PAGE_SIZE - offset_in_page(pos));
> > > +
> > >  	/* i_rwsem is held by caller */
> > >  	if (unlikely(info->seals & (F_SEAL_GROW |
> > >  				   F_SEAL_WRITE | F_SEAL_FUTURE_WRITE))) {
> > > @@ -2963,7 +2967,7 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
> > >  			return -EPERM;
> > >  	}
> > >  
> > > -	ret = shmem_get_folio(inode, index, &folio, SGP_WRITE);
> > > +	ret = shmem_get_folio(inode, index, &folio, SGP_WRITE, len);
> > >  	if (ret)
> > >  		return ret;
> > >  
> > > @@ -3083,7 +3087,7 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
> > >  				break;
> > >  		}
> > >  
> > > -		error = shmem_get_folio(inode, index, &folio, SGP_READ);
> > > +		error = shmem_get_folio(inode, index, &folio, SGP_READ, PAGE_SIZE);
> > >  		if (error) {
> > >  			if (error == -EINVAL)
> > >  				error = 0;
> > > @@ -3260,7 +3264,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
> > >  			break;
> > >  
> > >  		error = shmem_get_folio(inode, *ppos / PAGE_SIZE, &folio,
> > > -					SGP_READ);
> > > +					SGP_READ, PAGE_SIZE);
> > >  		if (error) {
> > >  			if (error == -EINVAL)
> > >  				error = 0;
> > > @@ -3469,7 +3473,8 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
> > >  			error = -ENOMEM;
> > >  		else
> > >  			error = shmem_get_folio(inode, index, &folio,
> > > -						SGP_FALLOC);
> > > +						SGP_FALLOC,
> > > +						(end - index) << PAGE_SHIFT);
> > >  		if (error) {
> > >  			info->fallocend = undo_fallocend;
> > >  			/* Remove the !uptodate folios we added */
> > > @@ -3822,7 +3827,7 @@ static int shmem_symlink(struct mnt_idmap *idmap, struct inode *dir,
> > >  	} else {
> > >  		inode_nohighmem(inode);
> > >  		inode->i_mapping->a_ops = &shmem_aops;
> > > -		error = shmem_get_folio(inode, 0, &folio, SGP_WRITE);
> > > +		error = shmem_get_folio(inode, 0, &folio, SGP_WRITE, PAGE_SIZE);
> > >  		if (error)
> > >  			goto out_remove_offset;
> > >  		inode->i_op = &shmem_symlink_inode_operations;
> > > @@ -3868,7 +3873,7 @@ static const char *shmem_get_link(struct dentry *dentry, struct inode *inode,
> > >  			return ERR_PTR(-ECHILD);
> > >  		}
> > >  	} else {
> > > -		error = shmem_get_folio(inode, 0, &folio, SGP_READ);
> > > +		error = shmem_get_folio(inode, 0, &folio, SGP_READ, PAGE_SIZE);
> > >  		if (error)
> > >  			return ERR_PTR(error);
> > >  		if (!folio)
> > > @@ -5255,7 +5260,7 @@ struct folio *shmem_read_folio_gfp(struct address_space *mapping,
> > >  	int error;
> > >  
> > >  	error = shmem_get_folio_gfp(inode, index, &folio, SGP_CACHE,
> > > -				    gfp, NULL, NULL);
> > > +				    gfp, NULL, NULL, PAGE_SIZE);
> > >  	if (error)
> > >  		return ERR_PTR(error);
> > >  
> > > diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
> > > index 3c3539c573e7..540a0c2d4325 100644
> > > --- a/mm/userfaultfd.c
> > > +++ b/mm/userfaultfd.c
> > > @@ -359,7 +359,7 @@ static int mfill_atomic_pte_continue(pmd_t *dst_pmd,
> > >  	struct page *page;
> > >  	int ret;
> > >  
> > > -	ret = shmem_get_folio(inode, pgoff, &folio, SGP_NOALLOC);
> > > +	ret = shmem_get_folio(inode, pgoff, &folio, SGP_NOALLOC, PAGE_SIZE);
> > >  	/* Our caller expects us to return -EFAULT if we failed to find folio */
> > >  	if (ret == -ENOENT)
> > >  		ret = -EFAULT;
> > > -- 
> > > 2.43.0
> > >
diff mbox series

Patch

diff --git a/fs/xfs/scrub/xfile.c b/fs/xfs/scrub/xfile.c
index 8cdd863db585..4905f5e4cb5d 100644
--- a/fs/xfs/scrub/xfile.c
+++ b/fs/xfs/scrub/xfile.c
@@ -127,7 +127,7 @@  xfile_load(
 		unsigned int	offset;
 
 		if (shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
-				SGP_READ) < 0)
+				SGP_READ, PAGE_SIZE) < 0)
 			break;
 		if (!folio) {
 			/*
@@ -197,7 +197,7 @@  xfile_store(
 		unsigned int	offset;
 
 		if (shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
-				SGP_CACHE) < 0)
+				SGP_CACHE, PAGE_SIZE) < 0)
 			break;
 		if (filemap_check_wb_err(inode->i_mapping, 0)) {
 			folio_unlock(folio);
@@ -268,7 +268,7 @@  xfile_get_folio(
 
 	pflags = memalloc_nofs_save();
 	error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
-			(flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ);
+			(flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ, PAGE_SIZE);
 	memalloc_nofs_restore(pflags);
 	if (error)
 		return ERR_PTR(error);
diff --git a/fs/xfs/xfs_buf_mem.c b/fs/xfs/xfs_buf_mem.c
index 9bb2d24de709..784c81d35a1f 100644
--- a/fs/xfs/xfs_buf_mem.c
+++ b/fs/xfs/xfs_buf_mem.c
@@ -149,7 +149,8 @@  xmbuf_map_page(
 		return -ENOMEM;
 	}
 
-	error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio, SGP_CACHE);
+	error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio, SGP_CACHE,
+				PAGE_SIZE);
 	if (error)
 		return error;
 
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 3fb18f7eb73e..bc59b4a00228 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -142,7 +142,7 @@  enum sgp_type {
 };
 
 int shmem_get_folio(struct inode *inode, pgoff_t index, struct folio **foliop,
-		enum sgp_type sgp);
+		enum sgp_type sgp, size_t len);
 struct folio *shmem_read_folio_gfp(struct address_space *mapping,
 		pgoff_t index, gfp_t gfp);
 
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 38830174608f..947770ded68c 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1863,7 +1863,8 @@  static int collapse_file(struct mm_struct *mm, unsigned long addr,
 				xas_unlock_irq(&xas);
 				/* swap in or instantiate fallocated page */
 				if (shmem_get_folio(mapping->host, index,
-						&folio, SGP_NOALLOC)) {
+						    &folio, SGP_NOALLOC,
+						    PAGE_SIZE)) {
 					result = SCAN_FAIL;
 					goto xa_unlocked;
 				}
diff --git a/mm/shmem.c b/mm/shmem.c
index d531018ffece..fcd2c9befe19 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1134,7 +1134,7 @@  static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index)
 	 * (although in some cases this is just a waste of time).
 	 */
 	folio = NULL;
-	shmem_get_folio(inode, index, &folio, SGP_READ);
+	shmem_get_folio(inode, index, &folio, SGP_READ, PAGE_SIZE);
 	return folio;
 }
 
@@ -1844,7 +1844,7 @@  static struct folio *shmem_alloc_folio(gfp_t gfp, struct shmem_inode_info *info,
 
 static struct folio *shmem_alloc_and_add_folio(gfp_t gfp,
 		struct inode *inode, pgoff_t index,
-		struct mm_struct *fault_mm, bool huge)
+		struct mm_struct *fault_mm, bool huge, size_t len)
 {
 	struct address_space *mapping = inode->i_mapping;
 	struct shmem_inode_info *info = SHMEM_I(inode);
@@ -2173,7 +2173,7 @@  static int shmem_swapin_folio(struct inode *inode, pgoff_t index,
  */
 static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
 		struct folio **foliop, enum sgp_type sgp, gfp_t gfp,
-		struct vm_fault *vmf, vm_fault_t *fault_type)
+		struct vm_fault *vmf, vm_fault_t *fault_type, size_t len)
 {
 	struct vm_area_struct *vma = vmf ? vmf->vma : NULL;
 	struct mm_struct *fault_mm;
@@ -2258,7 +2258,7 @@  static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
 		huge_gfp = vma_thp_gfp_mask(vma);
 		huge_gfp = limit_gfp_mask(huge_gfp, gfp);
 		folio = shmem_alloc_and_add_folio(huge_gfp,
-				inode, index, fault_mm, true);
+				inode, index, fault_mm, true, len);
 		if (!IS_ERR(folio)) {
 			count_vm_event(THP_FILE_ALLOC);
 			goto alloced;
@@ -2267,7 +2267,8 @@  static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
 			goto repeat;
 	}
 
-	folio = shmem_alloc_and_add_folio(gfp, inode, index, fault_mm, false);
+	folio = shmem_alloc_and_add_folio(gfp, inode, index, fault_mm, false,
+					  len);
 	if (IS_ERR(folio)) {
 		error = PTR_ERR(folio);
 		if (error == -EEXIST)
@@ -2377,10 +2378,10 @@  static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
  * Return: 0 if successful, else a negative error code.
  */
 int shmem_get_folio(struct inode *inode, pgoff_t index, struct folio **foliop,
-		enum sgp_type sgp)
+		enum sgp_type sgp, size_t len)
 {
 	return shmem_get_folio_gfp(inode, index, foliop, sgp,
-			mapping_gfp_mask(inode->i_mapping), NULL, NULL);
+			mapping_gfp_mask(inode->i_mapping), NULL, NULL, len);
 }
 EXPORT_SYMBOL_GPL(shmem_get_folio);
 
@@ -2475,7 +2476,7 @@  static vm_fault_t shmem_fault(struct vm_fault *vmf)
 
 	WARN_ON_ONCE(vmf->page != NULL);
 	err = shmem_get_folio_gfp(inode, vmf->pgoff, &folio, SGP_CACHE,
-				  gfp, vmf, &ret);
+				  gfp, vmf, &ret, PAGE_SIZE);
 	if (err)
 		return vmf_error(err);
 	if (folio) {
@@ -2954,6 +2955,9 @@  shmem_write_begin(struct file *file, struct address_space *mapping,
 	struct folio *folio;
 	int ret = 0;
 
+	if (!mapping_large_folio_support(mapping))
+		len = min_t(size_t, len, PAGE_SIZE - offset_in_page(pos));
+
 	/* i_rwsem is held by caller */
 	if (unlikely(info->seals & (F_SEAL_GROW |
 				   F_SEAL_WRITE | F_SEAL_FUTURE_WRITE))) {
@@ -2963,7 +2967,7 @@  shmem_write_begin(struct file *file, struct address_space *mapping,
 			return -EPERM;
 	}
 
-	ret = shmem_get_folio(inode, index, &folio, SGP_WRITE);
+	ret = shmem_get_folio(inode, index, &folio, SGP_WRITE, len);
 	if (ret)
 		return ret;
 
@@ -3083,7 +3087,7 @@  static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 				break;
 		}
 
-		error = shmem_get_folio(inode, index, &folio, SGP_READ);
+		error = shmem_get_folio(inode, index, &folio, SGP_READ, PAGE_SIZE);
 		if (error) {
 			if (error == -EINVAL)
 				error = 0;
@@ -3260,7 +3264,7 @@  static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
 			break;
 
 		error = shmem_get_folio(inode, *ppos / PAGE_SIZE, &folio,
-					SGP_READ);
+					SGP_READ, PAGE_SIZE);
 		if (error) {
 			if (error == -EINVAL)
 				error = 0;
@@ -3469,7 +3473,8 @@  static long shmem_fallocate(struct file *file, int mode, loff_t offset,
 			error = -ENOMEM;
 		else
 			error = shmem_get_folio(inode, index, &folio,
-						SGP_FALLOC);
+						SGP_FALLOC,
+						(end - index) << PAGE_SHIFT);
 		if (error) {
 			info->fallocend = undo_fallocend;
 			/* Remove the !uptodate folios we added */
@@ -3822,7 +3827,7 @@  static int shmem_symlink(struct mnt_idmap *idmap, struct inode *dir,
 	} else {
 		inode_nohighmem(inode);
 		inode->i_mapping->a_ops = &shmem_aops;
-		error = shmem_get_folio(inode, 0, &folio, SGP_WRITE);
+		error = shmem_get_folio(inode, 0, &folio, SGP_WRITE, PAGE_SIZE);
 		if (error)
 			goto out_remove_offset;
 		inode->i_op = &shmem_symlink_inode_operations;
@@ -3868,7 +3873,7 @@  static const char *shmem_get_link(struct dentry *dentry, struct inode *inode,
 			return ERR_PTR(-ECHILD);
 		}
 	} else {
-		error = shmem_get_folio(inode, 0, &folio, SGP_READ);
+		error = shmem_get_folio(inode, 0, &folio, SGP_READ, PAGE_SIZE);
 		if (error)
 			return ERR_PTR(error);
 		if (!folio)
@@ -5255,7 +5260,7 @@  struct folio *shmem_read_folio_gfp(struct address_space *mapping,
 	int error;
 
 	error = shmem_get_folio_gfp(inode, index, &folio, SGP_CACHE,
-				    gfp, NULL, NULL);
+				    gfp, NULL, NULL, PAGE_SIZE);
 	if (error)
 		return ERR_PTR(error);
 
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 3c3539c573e7..540a0c2d4325 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -359,7 +359,7 @@  static int mfill_atomic_pte_continue(pmd_t *dst_pmd,
 	struct page *page;
 	int ret;
 
-	ret = shmem_get_folio(inode, pgoff, &folio, SGP_NOALLOC);
+	ret = shmem_get_folio(inode, pgoff, &folio, SGP_NOALLOC, PAGE_SIZE);
 	/* Our caller expects us to return -EFAULT if we failed to find folio */
 	if (ret == -ENOENT)
 		ret = -EFAULT;