From: Christoph Hellwig <hch@lst.de>
To: Andrew Morton <akpm@linux-foundation.org>,
Matthew Wilcox <willy@infradead.org>,
Hugh Dickins <hughd@google.com>
Cc: linux-afs@lists.infradead.org, linux-btrfs@vger.kernel.org,
linux-ext4@vger.kernel.org, cluster-devel@redhat.com,
linux-mm@kvack.org, linux-xfs@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-nilfs@vger.kernel.org
Subject: [PATCH 5/9] shmem: open code the page cache lookup in shmem_get_folio_gfp
Date: Wed, 18 Jan 2023 10:43:25 +0100 [thread overview]
Message-ID: <20230118094329.9553-6-hch@lst.de> (raw)
In-Reply-To: <20230118094329.9553-1-hch@lst.de>
Use the very low level filemap_get_entry helper to look up the
entry in the xarray, and then:
- don't bother locking the folio if only doing a userfault notification
- open code locking the page and checking for truncation in a related
code block
This will allow to eventually remove the FGP_ENTRY flag.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
mm/shmem.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index e9500fea43a8dc..769107f376562f 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1856,12 +1856,10 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
sbinfo = SHMEM_SB(inode->i_sb);
charge_mm = vma ? vma->vm_mm : NULL;
- folio = __filemap_get_folio(mapping, index, FGP_ENTRY | FGP_LOCK, 0);
+ folio = filemap_get_entry(mapping, index);
if (folio && vma && userfaultfd_minor(vma)) {
- if (!xa_is_value(folio)) {
- folio_unlock(folio);
+ if (!xa_is_value(folio))
folio_put(folio);
- }
*fault_type = handle_userfault(vmf, VM_UFFD_MINOR);
return 0;
}
@@ -1877,6 +1875,14 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
}
if (folio) {
+ folio_lock(folio);
+
+ /* Has the page been truncated? */
+ if (unlikely(folio->mapping != mapping)) {
+ folio_unlock(folio);
+ folio_put(folio);
+ goto repeat;
+ }
if (sgp == SGP_WRITE)
folio_mark_accessed(folio);
if (folio_test_uptodate(folio))
--
2.39.0
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: cluster-devel.redhat.com
Subject: [Cluster-devel] [PATCH 5/9] shmem: open code the page cache lookup in shmem_get_folio_gfp
Date: Wed, 18 Jan 2023 10:43:25 +0100 [thread overview]
Message-ID: <20230118094329.9553-6-hch@lst.de> (raw)
In-Reply-To: <20230118094329.9553-1-hch@lst.de>
Use the very low level filemap_get_entry helper to look up the
entry in the xarray, and then:
- don't bother locking the folio if only doing a userfault notification
- open code locking the page and checking for truncation in a related
code block
This will allow to eventually remove the FGP_ENTRY flag.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
mm/shmem.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index e9500fea43a8dc..769107f376562f 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1856,12 +1856,10 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
sbinfo = SHMEM_SB(inode->i_sb);
charge_mm = vma ? vma->vm_mm : NULL;
- folio = __filemap_get_folio(mapping, index, FGP_ENTRY | FGP_LOCK, 0);
+ folio = filemap_get_entry(mapping, index);
if (folio && vma && userfaultfd_minor(vma)) {
- if (!xa_is_value(folio)) {
- folio_unlock(folio);
+ if (!xa_is_value(folio))
folio_put(folio);
- }
*fault_type = handle_userfault(vmf, VM_UFFD_MINOR);
return 0;
}
@@ -1877,6 +1875,14 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
}
if (folio) {
+ folio_lock(folio);
+
+ /* Has the page been truncated? */
+ if (unlikely(folio->mapping != mapping)) {
+ folio_unlock(folio);
+ folio_put(folio);
+ goto repeat;
+ }
if (sgp == SGP_WRITE)
folio_mark_accessed(folio);
if (folio_test_uptodate(folio))
--
2.39.0
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Andrew Morton <akpm@linux-foundation.org>,
Matthew Wilcox <willy@infradead.org>,
Hugh Dickins <hughd@google.com>
Cc: linux-xfs@vger.kernel.org, linux-nilfs@vger.kernel.org,
cluster-devel@redhat.com, linux-mm@kvack.org,
linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org,
linux-afs@lists.infradead.org, linux-btrfs@vger.kernel.org
Subject: [PATCH 5/9] shmem: open code the page cache lookup in shmem_get_folio_gfp
Date: Wed, 18 Jan 2023 10:43:25 +0100 [thread overview]
Message-ID: <20230118094329.9553-6-hch@lst.de> (raw)
In-Reply-To: <20230118094329.9553-1-hch@lst.de>
Use the very low level filemap_get_entry helper to look up the
entry in the xarray, and then:
- don't bother locking the folio if only doing a userfault notification
- open code locking the page and checking for truncation in a related
code block
This will allow to eventually remove the FGP_ENTRY flag.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
mm/shmem.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index e9500fea43a8dc..769107f376562f 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1856,12 +1856,10 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
sbinfo = SHMEM_SB(inode->i_sb);
charge_mm = vma ? vma->vm_mm : NULL;
- folio = __filemap_get_folio(mapping, index, FGP_ENTRY | FGP_LOCK, 0);
+ folio = filemap_get_entry(mapping, index);
if (folio && vma && userfaultfd_minor(vma)) {
- if (!xa_is_value(folio)) {
- folio_unlock(folio);
+ if (!xa_is_value(folio))
folio_put(folio);
- }
*fault_type = handle_userfault(vmf, VM_UFFD_MINOR);
return 0;
}
@@ -1877,6 +1875,14 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
}
if (folio) {
+ folio_lock(folio);
+
+ /* Has the page been truncated? */
+ if (unlikely(folio->mapping != mapping)) {
+ folio_unlock(folio);
+ folio_put(folio);
+ goto repeat;
+ }
if (sgp == SGP_WRITE)
folio_mark_accessed(folio);
if (folio_test_uptodate(folio))
--
2.39.0
next prev parent reply other threads:[~2023-01-18 10:41 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-18 9:43 return an ERR_PTR from __filemap_get_folio Christoph Hellwig
2023-01-18 9:43 ` [Cluster-devel] " Christoph Hellwig
2023-01-18 9:43 ` [PATCH 1/9] mm: don't look at xarray value entries in split_huge_pages_in_file Christoph Hellwig
2023-01-18 9:43 ` Christoph Hellwig
2023-01-18 9:43 ` [Cluster-devel] " Christoph Hellwig
2023-01-18 13:47 ` Matthew Wilcox
2023-01-18 13:47 ` Matthew Wilcox
2023-01-18 13:47 ` [Cluster-devel] " Matthew Wilcox
2023-01-18 9:43 ` [PATCH 2/9] mm: make mapping_get_entry available outside of filemap.c Christoph Hellwig
2023-01-18 9:43 ` Christoph Hellwig
2023-01-18 9:43 ` [Cluster-devel] " Christoph Hellwig
2023-01-18 13:49 ` Matthew Wilcox
2023-01-18 13:49 ` Matthew Wilcox
2023-01-18 13:49 ` [Cluster-devel] " Matthew Wilcox
2023-01-18 9:43 ` [PATCH 3/9] mm: use filemap_get_entry in filemap_get_incore_folio Christoph Hellwig
2023-01-18 9:43 ` Christoph Hellwig
2023-01-18 9:43 ` [Cluster-devel] " Christoph Hellwig
2023-01-18 13:49 ` Matthew Wilcox
2023-01-18 13:49 ` Matthew Wilcox
2023-01-18 13:49 ` [Cluster-devel] " Matthew Wilcox
2023-01-18 9:43 ` [PATCH 4/9] shmem: remove shmem_get_partial_folio Christoph Hellwig
2023-01-18 9:43 ` Christoph Hellwig
2023-01-18 9:43 ` [Cluster-devel] " Christoph Hellwig
2023-01-18 13:57 ` Brian Foster
2023-01-18 13:57 ` Brian Foster
2023-01-18 13:57 ` [Cluster-devel] " Brian Foster
2023-01-18 16:43 ` Christoph Hellwig
2023-01-18 16:43 ` Christoph Hellwig
2023-01-18 16:43 ` [Cluster-devel] " Christoph Hellwig
2023-01-18 16:50 ` Brian Foster
2023-01-18 16:50 ` Brian Foster
2023-01-18 16:50 ` [Cluster-devel] " Brian Foster
2023-01-18 9:43 ` Christoph Hellwig [this message]
2023-01-18 9:43 ` [PATCH 5/9] shmem: open code the page cache lookup in shmem_get_folio_gfp Christoph Hellwig
2023-01-18 9:43 ` [Cluster-devel] " Christoph Hellwig
2023-01-18 9:43 ` [PATCH 6/9] mm: remove FGP_ENTRY Christoph Hellwig
2023-01-18 9:43 ` Christoph Hellwig
2023-01-18 9:43 ` [Cluster-devel] " Christoph Hellwig
2023-01-18 9:43 ` [PATCH 7/9] gfs2: handle a NULL folio in gfs2_jhead_process_page Christoph Hellwig
2023-01-18 9:43 ` Christoph Hellwig
2023-01-18 9:43 ` [Cluster-devel] " Christoph Hellwig
2023-01-18 16:00 ` Matthew Wilcox
2023-01-18 16:00 ` Matthew Wilcox
2023-01-18 16:00 ` [Cluster-devel] " Matthew Wilcox
2023-01-18 16:24 ` Andreas Gruenbacher
2023-01-18 16:24 ` Andreas Gruenbacher
2023-01-18 16:24 ` [Cluster-devel] " Andreas Gruenbacher
2023-01-18 16:42 ` Christoph Hellwig
2023-01-18 16:42 ` Christoph Hellwig
2023-01-18 9:43 ` [PATCH 8/9] btrfs: handle a NULL folio in extent_range_redirty_for_io Christoph Hellwig
2023-01-18 9:43 ` Christoph Hellwig
2023-01-18 9:43 ` [Cluster-devel] " Christoph Hellwig
2023-01-18 16:08 ` Matthew Wilcox
2023-01-18 16:08 ` Matthew Wilcox
2023-01-18 16:08 ` [Cluster-devel] " Matthew Wilcox
2023-01-18 16:42 ` Christoph Hellwig
2023-01-18 16:42 ` Christoph Hellwig
2023-01-18 16:42 ` [Cluster-devel] " Christoph Hellwig
2023-01-18 9:43 ` [PATCH 9/9] mm: return an ERR_PTR from __filemap_get_folio Christoph Hellwig
2023-01-18 9:43 ` Christoph Hellwig
2023-01-18 9:43 ` [Cluster-devel] " Christoph Hellwig
2023-01-18 12:39 ` Ryusuke Konishi
2023-01-18 12:39 ` Ryusuke Konishi
2023-01-18 12:39 ` [Cluster-devel] " Ryusuke Konishi
2023-01-18 16:42 ` Christoph Hellwig
2023-01-18 16:42 ` Christoph Hellwig
2023-01-18 16:42 ` [Cluster-devel] " Christoph Hellwig
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