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-rw-r--r--mm/shmem.c271
1 files changed, 123 insertions, 148 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 3107acee4f71..88742953532c 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -38,8 +38,7 @@
#include <linux/hugetlb.h>
#include <linux/frontswap.h>
#include <linux/fs_parser.h>
-
-#include <asm/tlbflush.h> /* for arch/microblaze update_mmu_cache() */
+#include <linux/swapfile.h>
static struct vfsmount *shm_mnt;
@@ -137,9 +136,6 @@ static unsigned long shmem_default_max_inodes(void)
}
#endif
-static bool shmem_should_replace_page(struct page *page, gfp_t gfp);
-static int shmem_replace_page(struct page **pagep, gfp_t gfp,
- struct shmem_inode_info *info, pgoff_t index);
static int shmem_swapin_page(struct inode *inode, pgoff_t index,
struct page **pagep, enum sgp_type sgp,
gfp_t gfp, struct vm_area_struct *vma,
@@ -278,10 +274,10 @@ static int shmem_reserve_inode(struct super_block *sb, ino_t *inop)
ino_t ino;
if (!(sb->s_flags & SB_KERNMOUNT)) {
- spin_lock(&sbinfo->stat_lock);
+ raw_spin_lock(&sbinfo->stat_lock);
if (sbinfo->max_inodes) {
if (!sbinfo->free_inodes) {
- spin_unlock(&sbinfo->stat_lock);
+ raw_spin_unlock(&sbinfo->stat_lock);
return -ENOSPC;
}
sbinfo->free_inodes--;
@@ -304,7 +300,7 @@ static int shmem_reserve_inode(struct super_block *sb, ino_t *inop)
}
*inop = ino;
}
- spin_unlock(&sbinfo->stat_lock);
+ raw_spin_unlock(&sbinfo->stat_lock);
} else if (inop) {
/*
* __shmem_file_setup, one of our callers, is lock-free: it
@@ -319,13 +315,14 @@ static int shmem_reserve_inode(struct super_block *sb, ino_t *inop)
* to worry about things like glibc compatibility.
*/
ino_t *next_ino;
+
next_ino = per_cpu_ptr(sbinfo->ino_batch, get_cpu());
ino = *next_ino;
if (unlikely(ino % SHMEM_INO_BATCH == 0)) {
- spin_lock(&sbinfo->stat_lock);
+ raw_spin_lock(&sbinfo->stat_lock);
ino = sbinfo->next_ino;
sbinfo->next_ino += SHMEM_INO_BATCH;
- spin_unlock(&sbinfo->stat_lock);
+ raw_spin_unlock(&sbinfo->stat_lock);
if (unlikely(is_zero_ino(ino)))
ino++;
}
@@ -341,9 +338,9 @@ static void shmem_free_inode(struct super_block *sb)
{
struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
if (sbinfo->max_inodes) {
- spin_lock(&sbinfo->stat_lock);
+ raw_spin_lock(&sbinfo->stat_lock);
sbinfo->free_inodes++;
- spin_unlock(&sbinfo->stat_lock);
+ raw_spin_unlock(&sbinfo->stat_lock);
}
}
@@ -474,7 +471,38 @@ static bool shmem_confirm_swap(struct address_space *mapping,
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/* ifdef here to avoid bloating shmem.o when not necessary */
-static int shmem_huge __read_mostly;
+static int shmem_huge __read_mostly = SHMEM_HUGE_NEVER;
+
+bool shmem_is_huge(struct vm_area_struct *vma,
+ struct inode *inode, pgoff_t index)
+{
+ loff_t i_size;
+
+ if (shmem_huge == SHMEM_HUGE_DENY)
+ return false;
+ if (vma && ((vma->vm_flags & VM_NOHUGEPAGE) ||
+ test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)))
+ return false;
+ if (shmem_huge == SHMEM_HUGE_FORCE)
+ return true;
+
+ switch (SHMEM_SB(inode->i_sb)->huge) {
+ case SHMEM_HUGE_ALWAYS:
+ return true;
+ case SHMEM_HUGE_WITHIN_SIZE:
+ index = round_up(index, HPAGE_PMD_NR);
+ i_size = round_up(i_size_read(inode), PAGE_SIZE);
+ if (i_size >= HPAGE_PMD_SIZE && (i_size >> PAGE_SHIFT) >= index)
+ return true;
+ fallthrough;
+ case SHMEM_HUGE_ADVISE:
+ if (vma && (vma->vm_flags & VM_HUGEPAGE))
+ return true;
+ fallthrough;
+ default:
+ return false;
+ }
+}
#if defined(CONFIG_SYSFS)
static int shmem_parse_huge(const char *str)
@@ -645,6 +673,12 @@ static long shmem_unused_huge_count(struct super_block *sb,
#define shmem_huge SHMEM_HUGE_DENY
+bool shmem_is_huge(struct vm_area_struct *vma,
+ struct inode *inode, pgoff_t index)
+{
+ return false;
+}
+
static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo,
struct shrink_control *sc, unsigned long nr_to_split)
{
@@ -652,15 +686,6 @@ static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo,
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-static inline bool is_huge_enabled(struct shmem_sb_info *sbinfo)
-{
- if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
- (shmem_huge == SHMEM_HUGE_FORCE || sbinfo->huge) &&
- shmem_huge != SHMEM_HUGE_DENY)
- return true;
- return false;
-}
-
/*
* Like add_to_page_cache_locked, but error if expected item has gone.
*/
@@ -905,6 +930,9 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
if (lend == -1)
end = -1; /* unsigned, so actually very big */
+ if (info->fallocend > start && info->fallocend <= end && !unfalloc)
+ info->fallocend = start;
+
pagevec_init(&pvec);
index = start;
while (index < end && find_lock_entries(mapping, index, end - 1,
@@ -1038,7 +1066,6 @@ static int shmem_getattr(struct user_namespace *mnt_userns,
{
struct inode *inode = path->dentry->d_inode;
struct shmem_inode_info *info = SHMEM_I(inode);
- struct shmem_sb_info *sb_info = SHMEM_SB(inode->i_sb);
if (info->alloced - info->swapped != inode->i_mapping->nrpages) {
spin_lock_irq(&info->lock);
@@ -1047,7 +1074,7 @@ static int shmem_getattr(struct user_namespace *mnt_userns,
}
generic_fillattr(&init_user_ns, inode, stat);
- if (is_huge_enabled(sb_info))
+ if (shmem_is_huge(NULL, inode, 0))
stat->blksize = HPAGE_PMD_SIZE;
return 0;
@@ -1058,7 +1085,6 @@ static int shmem_setattr(struct user_namespace *mnt_userns,
{
struct inode *inode = d_inode(dentry);
struct shmem_inode_info *info = SHMEM_I(inode);
- struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
int error;
error = setattr_prepare(&init_user_ns, dentry, attr);
@@ -1094,24 +1120,6 @@ static int shmem_setattr(struct user_namespace *mnt_userns,
if (oldsize > holebegin)
unmap_mapping_range(inode->i_mapping,
holebegin, 0, 1);
-
- /*
- * Part of the huge page can be beyond i_size: subject
- * to shrink under memory pressure.
- */
- if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
- spin_lock(&sbinfo->shrinklist_lock);
- /*
- * _careful to defend against unlocked access to
- * ->shrink_list in shmem_unused_huge_shrink()
- */
- if (list_empty_careful(&info->shrinklist)) {
- list_add_tail(&info->shrinklist,
- &sbinfo->shrinklist);
- sbinfo->shrinklist_len++;
- }
- spin_unlock(&sbinfo->shrinklist_lock);
- }
}
}
@@ -1156,8 +1164,6 @@ static void shmem_evict_inode(struct inode *inode)
clear_inode(inode);
}
-extern struct swap_info_struct *swap_info[];
-
static int shmem_find_swap_entries(struct address_space *mapping,
pgoff_t start, unsigned int nr_entries,
struct page **entries, pgoff_t *indices,
@@ -1338,7 +1344,19 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
swp_entry_t swap;
pgoff_t index;
- VM_BUG_ON_PAGE(PageCompound(page), page);
+ /*
+ * If /sys/kernel/mm/transparent_hugepage/shmem_enabled is "always" or
+ * "force", drivers/gpu/drm/i915/gem/i915_gem_shmem.c gets huge pages,
+ * and its shmem_writeback() needs them to be split when swapping.
+ */
+ if (PageTransCompound(page)) {
+ /* Ensure the subpages are still dirty */
+ SetPageDirty(page);
+ if (split_huge_page(page) < 0)
+ goto redirty;
+ ClearPageDirty(page);
+ }
+
BUG_ON(!PageLocked(page));
mapping = page->mapping;
index = page->index;
@@ -1453,10 +1471,10 @@ static struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo)
{
struct mempolicy *mpol = NULL;
if (sbinfo->mpol) {
- spin_lock(&sbinfo->stat_lock); /* prevent replace/use races */
+ raw_spin_lock(&sbinfo->stat_lock); /* prevent replace/use races */
mpol = sbinfo->mpol;
mpol_get(mpol);
- spin_unlock(&sbinfo->stat_lock);
+ raw_spin_unlock(&sbinfo->stat_lock);
}
return mpol;
}
@@ -1798,7 +1816,6 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
struct shmem_sb_info *sbinfo;
struct mm_struct *charge_mm;
struct page *page;
- enum sgp_type sgp_huge = sgp;
pgoff_t hindex = index;
gfp_t huge_gfp;
int error;
@@ -1807,8 +1824,6 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
if (index > (MAX_LFS_FILESIZE >> PAGE_SHIFT))
return -EFBIG;
- if (sgp == SGP_NOHUGE || sgp == SGP_HUGE)
- sgp = SGP_CACHE;
repeat:
if (sgp <= SGP_CACHE &&
((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) {
@@ -1840,26 +1855,31 @@ repeat:
return error;
}
- if (page)
+ if (page) {
hindex = page->index;
- if (page && sgp == SGP_WRITE)
- mark_page_accessed(page);
-
- /* fallocated page? */
- if (page && !PageUptodate(page)) {
+ if (sgp == SGP_WRITE)
+ mark_page_accessed(page);
+ if (PageUptodate(page))
+ goto out;
+ /* fallocated page */
if (sgp != SGP_READ)
goto clear;
unlock_page(page);
put_page(page);
- page = NULL;
- hindex = index;
}
- if (page || sgp == SGP_READ)
- goto out;
/*
- * Fast cache lookup did not find it:
- * bring it back from swap or allocate.
+ * SGP_READ: succeed on hole, with NULL page, letting caller zero.
+ * SGP_NOALLOC: fail on hole, with NULL page, letting caller fail.
+ */
+ *pagep = NULL;
+ if (sgp == SGP_READ)
+ return 0;
+ if (sgp == SGP_NOALLOC)
+ return -ENOENT;
+
+ /*
+ * Fast cache lookup and swap lookup did not find it: allocate.
*/
if (vma && userfaultfd_missing(vma)) {
@@ -1867,36 +1887,12 @@ repeat:
return 0;
}
- /* shmem_symlink() */
- if (!shmem_mapping(mapping))
- goto alloc_nohuge;
- if (shmem_huge == SHMEM_HUGE_DENY || sgp_huge == SGP_NOHUGE)
- goto alloc_nohuge;
- if (shmem_huge == SHMEM_HUGE_FORCE)
- goto alloc_huge;
- switch (sbinfo->huge) {
- case SHMEM_HUGE_NEVER:
+ /* Never use a huge page for shmem_symlink() */
+ if (S_ISLNK(inode->i_mode))
goto alloc_nohuge;
- case SHMEM_HUGE_WITHIN_SIZE: {
- loff_t i_size;
- pgoff_t off;
-
- off = round_up(index, HPAGE_PMD_NR);
- i_size = round_up(i_size_read(inode), PAGE_SIZE);
- if (i_size >= HPAGE_PMD_SIZE &&
- i_size >> PAGE_SHIFT >= off)
- goto alloc_huge;
-
- fallthrough;
- }
- case SHMEM_HUGE_ADVISE:
- if (sgp_huge == SGP_HUGE)
- goto alloc_huge;
- /* TODO: implement fadvise() hints */
+ if (!shmem_is_huge(vma, inode, index))
goto alloc_nohuge;
- }
-alloc_huge:
huge_gfp = vma_thp_gfp_mask(vma);
huge_gfp = limit_gfp_mask(huge_gfp, gfp);
page = shmem_alloc_and_acct_page(huge_gfp, inode, index, true);
@@ -2052,7 +2048,6 @@ static vm_fault_t shmem_fault(struct vm_fault *vmf)
struct vm_area_struct *vma = vmf->vma;
struct inode *inode = file_inode(vma->vm_file);
gfp_t gfp = mapping_gfp_mask(inode->i_mapping);
- enum sgp_type sgp;
int err;
vm_fault_t ret = VM_FAULT_LOCKED;
@@ -2115,15 +2110,7 @@ static vm_fault_t shmem_fault(struct vm_fault *vmf)
spin_unlock(&inode->i_lock);
}
- sgp = SGP_CACHE;
-
- if ((vma->vm_flags & VM_NOHUGEPAGE) ||
- test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
- sgp = SGP_NOHUGE;
- else if (vma->vm_flags & VM_HUGEPAGE)
- sgp = SGP_HUGE;
-
- err = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, sgp,
+ err = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, SGP_CACHE,
gfp, vma, vmf, &ret);
if (err)
return vmf_error(err);
@@ -2655,7 +2642,7 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
struct shmem_inode_info *info = SHMEM_I(inode);
struct shmem_falloc shmem_falloc;
- pgoff_t start, index, end;
+ pgoff_t start, index, end, undo_fallocend;
int error;
if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
@@ -2724,7 +2711,16 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
inode->i_private = &shmem_falloc;
spin_unlock(&inode->i_lock);
- for (index = start; index < end; index++) {
+ /*
+ * info->fallocend is only relevant when huge pages might be
+ * involved: to prevent split_huge_page() freeing fallocated
+ * pages when FALLOC_FL_KEEP_SIZE committed beyond i_size.
+ */
+ undo_fallocend = info->fallocend;
+ if (info->fallocend < end)
+ info->fallocend = end;
+
+ for (index = start; index < end; ) {
struct page *page;
/*
@@ -2738,6 +2734,7 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
else
error = shmem_getpage(inode, index, &page, SGP_FALLOC);
if (error) {
+ info->fallocend = undo_fallocend;
/* Remove the !PageUptodate pages we added */
if (index > start) {
shmem_undo_range(inode,
@@ -2747,13 +2744,26 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
goto undone;
}
+ index++;
+ /*
+ * Here is a more important optimization than it appears:
+ * a second SGP_FALLOC on the same huge page will clear it,
+ * making it PageUptodate and un-undoable if we fail later.
+ */
+ if (PageTransCompound(page)) {
+ index = round_up(index, HPAGE_PMD_NR);
+ /* Beware 32-bit wraparound */
+ if (!index)
+ index--;
+ }
+
/*
* Inform shmem_writepage() how far we have reached.
* No need for lock or barrier: we have the page lock.
*/
- shmem_falloc.next++;
if (!PageUptodate(page))
- shmem_falloc.nr_falloced++;
+ shmem_falloc.nr_falloced += index - shmem_falloc.next;
+ shmem_falloc.next = index;
/*
* If !PageUptodate, leave it that way so that freeable pages
@@ -3488,9 +3498,10 @@ static int shmem_reconfigure(struct fs_context *fc)
struct shmem_options *ctx = fc->fs_private;
struct shmem_sb_info *sbinfo = SHMEM_SB(fc->root->d_sb);
unsigned long inodes;
+ struct mempolicy *mpol = NULL;
const char *err;
- spin_lock(&sbinfo->stat_lock);
+ raw_spin_lock(&sbinfo->stat_lock);
inodes = sbinfo->max_inodes - sbinfo->free_inodes;
if ((ctx->seen & SHMEM_SEEN_BLOCKS) && ctx->blocks) {
if (!sbinfo->max_blocks) {
@@ -3535,14 +3546,15 @@ static int shmem_reconfigure(struct fs_context *fc)
* Preserve previous mempolicy unless mpol remount option was specified.
*/
if (ctx->mpol) {
- mpol_put(sbinfo->mpol);
+ mpol = sbinfo->mpol;
sbinfo->mpol = ctx->mpol; /* transfers initial ref */
ctx->mpol = NULL;
}
- spin_unlock(&sbinfo->stat_lock);
+ raw_spin_unlock(&sbinfo->stat_lock);
+ mpol_put(mpol);
return 0;
out:
- spin_unlock(&sbinfo->stat_lock);
+ raw_spin_unlock(&sbinfo->stat_lock);
return invalfc(fc, "%s", err);
}
@@ -3613,7 +3625,6 @@ static int shmem_fill_super(struct super_block *sb, struct fs_context *fc)
struct shmem_options *ctx = fc->fs_private;
struct inode *inode;
struct shmem_sb_info *sbinfo;
- int err = -ENOMEM;
/* Round up to L1_CACHE_BYTES to resist false sharing */
sbinfo = kzalloc(max((int)sizeof(struct shmem_sb_info),
@@ -3659,7 +3670,7 @@ static int shmem_fill_super(struct super_block *sb, struct fs_context *fc)
sbinfo->mpol = ctx->mpol;
ctx->mpol = NULL;
- spin_lock_init(&sbinfo->stat_lock);
+ raw_spin_lock_init(&sbinfo->stat_lock);
if (percpu_counter_init(&sbinfo->used_blocks, 0, GFP_KERNEL))
goto failed;
spin_lock_init(&sbinfo->shrinklist_lock);
@@ -3691,7 +3702,7 @@ static int shmem_fill_super(struct super_block *sb, struct fs_context *fc)
failed:
shmem_put_super(sb);
- return err;
+ return -ENOMEM;
}
static int shmem_get_tree(struct fs_context *fc)
@@ -3907,7 +3918,7 @@ int __init shmem_init(void)
if (has_transparent_hugepage() && shmem_huge > SHMEM_HUGE_DENY)
SHMEM_SB(shm_mnt->mnt_sb)->huge = shmem_huge;
else
- shmem_huge = 0; /* just in case it was patched */
+ shmem_huge = SHMEM_HUGE_NEVER; /* just in case it was patched */
#endif
return 0;
@@ -3976,42 +3987,6 @@ struct kobj_attribute shmem_enabled_attr =
__ATTR(shmem_enabled, 0644, shmem_enabled_show, shmem_enabled_store);
#endif /* CONFIG_TRANSPARENT_HUGEPAGE && CONFIG_SYSFS */
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-bool shmem_huge_enabled(struct vm_area_struct *vma)
-{
- struct inode *inode = file_inode(vma->vm_file);
- struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
- loff_t i_size;
- pgoff_t off;
-
- if (!transhuge_vma_enabled(vma, vma->vm_flags))
- return false;
- if (shmem_huge == SHMEM_HUGE_FORCE)
- return true;
- if (shmem_huge == SHMEM_HUGE_DENY)
- return false;
- switch (sbinfo->huge) {
- case SHMEM_HUGE_NEVER:
- return false;
- case SHMEM_HUGE_ALWAYS:
- return true;
- case SHMEM_HUGE_WITHIN_SIZE:
- off = round_up(vma->vm_pgoff, HPAGE_PMD_NR);
- i_size = round_up(i_size_read(inode), PAGE_SIZE);
- if (i_size >= HPAGE_PMD_SIZE &&
- i_size >> PAGE_SHIFT >= off)
- return true;
- fallthrough;
- case SHMEM_HUGE_ADVISE:
- /* TODO: implement fadvise() hints */
- return (vma->vm_flags & VM_HUGEPAGE);
- default:
- VM_BUG_ON(1);
- return false;
- }
-}
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-
#else /* !CONFIG_SHMEM */
/*