[PATCH 4.9 07/50] shmem: introduce shmem_inode_acct_block

From: Greg Kroah-Hartman
Date: Tue Dec 04 2018 - 06:09:11 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

commit 0f0796945614b7523987f7eea32407421af4b1ee upstream.

The shmem_acct_block and the update of used_blocks are following one
another in all the places they are used. Combine these two into a
helper function.

Link: http://lkml.kernel.org/r/1497939652-16528-3-git-send-email-rppt@xxxxxxxxxxxxxxxxxx
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
mm/shmem.c | 82 ++++++++++++++++++++++++++++--------------------------
1 file changed, 42 insertions(+), 40 deletions(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index b26f11221ea8..e30ffaa065a4 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -181,6 +181,38 @@ static inline void shmem_unacct_blocks(unsigned long flags, long pages)
vm_unacct_memory(pages * VM_ACCT(PAGE_SIZE));
}

+static inline bool shmem_inode_acct_block(struct inode *inode, long pages)
+{
+ struct shmem_inode_info *info = SHMEM_I(inode);
+ struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
+
+ if (shmem_acct_block(info->flags, pages))
+ return false;
+
+ if (sbinfo->max_blocks) {
+ if (percpu_counter_compare(&sbinfo->used_blocks,
+ sbinfo->max_blocks - pages) > 0)
+ goto unacct;
+ percpu_counter_add(&sbinfo->used_blocks, pages);
+ }
+
+ return true;
+
+unacct:
+ shmem_unacct_blocks(info->flags, pages);
+ return false;
+}
+
+static inline void shmem_inode_unacct_blocks(struct inode *inode, long pages)
+{
+ struct shmem_inode_info *info = SHMEM_I(inode);
+ struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
+
+ if (sbinfo->max_blocks)
+ percpu_counter_sub(&sbinfo->used_blocks, pages);
+ shmem_unacct_blocks(info->flags, pages);
+}
+
static const struct super_operations shmem_ops;
static const struct address_space_operations shmem_aops;
static const struct file_operations shmem_file_operations;
@@ -237,31 +269,20 @@ static void shmem_recalc_inode(struct inode *inode)

freed = info->alloced - info->swapped - inode->i_mapping->nrpages;
if (freed > 0) {
- struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
- if (sbinfo->max_blocks)
- percpu_counter_add(&sbinfo->used_blocks, -freed);
info->alloced -= freed;
inode->i_blocks -= freed * BLOCKS_PER_PAGE;
- shmem_unacct_blocks(info->flags, freed);
+ shmem_inode_unacct_blocks(inode, freed);
}
}

bool shmem_charge(struct inode *inode, long pages)
{
struct shmem_inode_info *info = SHMEM_I(inode);
- struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
unsigned long flags;

- if (shmem_acct_block(info->flags, pages))
+ if (!shmem_inode_acct_block(inode, pages))
return false;

- if (sbinfo->max_blocks) {
- if (percpu_counter_compare(&sbinfo->used_blocks,
- sbinfo->max_blocks - pages) > 0)
- goto unacct;
- percpu_counter_add(&sbinfo->used_blocks, pages);
- }
-
spin_lock_irqsave(&info->lock, flags);
info->alloced += pages;
inode->i_blocks += pages * BLOCKS_PER_PAGE;
@@ -270,16 +291,11 @@ bool shmem_charge(struct inode *inode, long pages)
inode->i_mapping->nrpages += pages;

return true;
-
-unacct:
- shmem_unacct_blocks(info->flags, pages);
- return false;
}

void shmem_uncharge(struct inode *inode, long pages)
{
struct shmem_inode_info *info = SHMEM_I(inode);
- struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
unsigned long flags;

spin_lock_irqsave(&info->lock, flags);
@@ -288,9 +304,7 @@ void shmem_uncharge(struct inode *inode, long pages)
shmem_recalc_inode(inode);
spin_unlock_irqrestore(&info->lock, flags);

- if (sbinfo->max_blocks)
- percpu_counter_sub(&sbinfo->used_blocks, pages);
- shmem_unacct_blocks(info->flags, pages);
+ shmem_inode_unacct_blocks(inode, pages);
}

/*
@@ -1423,9 +1437,10 @@ static struct page *shmem_alloc_page(gfp_t gfp,
}

static struct page *shmem_alloc_and_acct_page(gfp_t gfp,
- struct shmem_inode_info *info, struct shmem_sb_info *sbinfo,
+ struct inode *inode,
pgoff_t index, bool huge)
{
+ struct shmem_inode_info *info = SHMEM_I(inode);
struct page *page;
int nr;
int err = -ENOSPC;
@@ -1434,14 +1449,8 @@ static struct page *shmem_alloc_and_acct_page(gfp_t gfp,
huge = false;
nr = huge ? HPAGE_PMD_NR : 1;

- if (shmem_acct_block(info->flags, nr))
+ if (!shmem_inode_acct_block(inode, nr))
goto failed;
- if (sbinfo->max_blocks) {
- if (percpu_counter_compare(&sbinfo->used_blocks,
- sbinfo->max_blocks - nr) > 0)
- goto unacct;
- percpu_counter_add(&sbinfo->used_blocks, nr);
- }

if (huge)
page = shmem_alloc_hugepage(gfp, info, index);
@@ -1454,10 +1463,7 @@ static struct page *shmem_alloc_and_acct_page(gfp_t gfp,
}

err = -ENOMEM;
- if (sbinfo->max_blocks)
- percpu_counter_add(&sbinfo->used_blocks, -nr);
-unacct:
- shmem_unacct_blocks(info->flags, nr);
+ shmem_inode_unacct_blocks(inode, nr);
failed:
return ERR_PTR(err);
}
@@ -1717,10 +1723,9 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
}

alloc_huge:
- page = shmem_alloc_and_acct_page(gfp, info, sbinfo,
- index, true);
+ page = shmem_alloc_and_acct_page(gfp, inode, index, true);
if (IS_ERR(page)) {
-alloc_nohuge: page = shmem_alloc_and_acct_page(gfp, info, sbinfo,
+alloc_nohuge: page = shmem_alloc_and_acct_page(gfp, inode,
index, false);
}
if (IS_ERR(page)) {
@@ -1842,10 +1847,7 @@ alloc_nohuge: page = shmem_alloc_and_acct_page(gfp, info, sbinfo,
* Error recovery.
*/
unacct:
- if (sbinfo->max_blocks)
- percpu_counter_sub(&sbinfo->used_blocks,
- 1 << compound_order(page));
- shmem_unacct_blocks(info->flags, 1 << compound_order(page));
+ shmem_inode_unacct_blocks(inode, 1 << compound_order(page));

if (PageTransHuge(page)) {
unlock_page(page);
--
2.17.1