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-rw-r--r--mm/shmem.c133
1 files changed, 78 insertions, 55 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index f65f840..dfaa0f4 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -28,6 +28,7 @@
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/module.h>
+#include <linux/percpu_counter.h>
#include <linux/swap.h>
static struct vfsmount *shm_mnt;
@@ -233,10 +234,10 @@ static void shmem_free_blocks(struct inode *inode, long pages)
{
struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
if (sbinfo->max_blocks) {
- spin_lock(&sbinfo->stat_lock);
- sbinfo->free_blocks += pages;
+ percpu_counter_add(&sbinfo->used_blocks, -pages);
+ spin_lock(&inode->i_lock);
inode->i_blocks -= pages*BLOCKS_PER_PAGE;
- spin_unlock(&sbinfo->stat_lock);
+ spin_unlock(&inode->i_lock);
}
}
@@ -416,19 +417,17 @@ static swp_entry_t *shmem_swp_alloc(struct shmem_inode_info *info, unsigned long
if (sgp == SGP_READ)
return shmem_swp_map(ZERO_PAGE(0));
/*
- * Test free_blocks against 1 not 0, since we have 1 data
+ * Test used_blocks against 1 less max_blocks, since we have 1 data
* page (and perhaps indirect index pages) yet to allocate:
* a waste to allocate index if we cannot allocate data.
*/
if (sbinfo->max_blocks) {
- spin_lock(&sbinfo->stat_lock);
- if (sbinfo->free_blocks <= 1) {
- spin_unlock(&sbinfo->stat_lock);
+ if (percpu_counter_compare(&sbinfo->used_blocks, (sbinfo->max_blocks - 1)) > 0)
return ERR_PTR(-ENOSPC);
- }
- sbinfo->free_blocks--;
+ percpu_counter_inc(&sbinfo->used_blocks);
+ spin_lock(&inode->i_lock);
inode->i_blocks += BLOCKS_PER_PAGE;
- spin_unlock(&sbinfo->stat_lock);
+ spin_unlock(&inode->i_lock);
}
spin_unlock(&info->lock);
@@ -767,6 +766,10 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
loff_t newsize = attr->ia_size;
int error;
+ error = inode_change_ok(inode, attr);
+ if (error)
+ return error;
+
if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)
&& newsize != inode->i_size) {
struct page *page = NULL;
@@ -801,25 +804,22 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
}
}
- error = simple_setsize(inode, newsize);
+ /* XXX(truncate): truncate_setsize should be called last */
+ truncate_setsize(inode, newsize);
if (page)
page_cache_release(page);
- if (error)
- return error;
shmem_truncate_range(inode, newsize, (loff_t)-1);
}
- error = inode_change_ok(inode, attr);
- if (!error)
- generic_setattr(inode, attr);
+ setattr_copy(inode, attr);
#ifdef CONFIG_TMPFS_POSIX_ACL
- if (!error && (attr->ia_valid & ATTR_MODE))
+ if (attr->ia_valid & ATTR_MODE)
error = generic_acl_chmod(inode);
#endif
return error;
}
-static void shmem_delete_inode(struct inode *inode)
+static void shmem_evict_inode(struct inode *inode)
{
struct shmem_inode_info *info = SHMEM_I(inode);
@@ -836,7 +836,7 @@ static void shmem_delete_inode(struct inode *inode)
}
BUG_ON(inode->i_blocks);
shmem_free_inode(inode->i_sb);
- clear_inode(inode);
+ end_writeback(inode);
}
static inline int shmem_find_swp(swp_entry_t entry, swp_entry_t *dir, swp_entry_t *edir)
@@ -933,7 +933,7 @@ found:
/*
* Move _head_ to start search for next from here.
- * But be careful: shmem_delete_inode checks list_empty without taking
+ * But be careful: shmem_evict_inode checks list_empty without taking
* mutex, and there's an instant in list_move_tail when info->swaplist
* would appear empty, if it were the only one on shmem_swaplist. We
* could avoid doing it if inode NULL; or use this minor optimization.
@@ -1223,6 +1223,7 @@ static int shmem_getpage(struct inode *inode, unsigned long idx,
struct shmem_sb_info *sbinfo;
struct page *filepage = *pagep;
struct page *swappage;
+ struct page *prealloc_page = NULL;
swp_entry_t *entry;
swp_entry_t swap;
gfp_t gfp;
@@ -1247,7 +1248,6 @@ repeat:
filepage = find_lock_page(mapping, idx);
if (filepage && PageUptodate(filepage))
goto done;
- error = 0;
gfp = mapping_gfp_mask(mapping);
if (!filepage) {
/*
@@ -1258,7 +1258,19 @@ repeat:
if (error)
goto failed;
radix_tree_preload_end();
+ if (sgp != SGP_READ && !prealloc_page) {
+ /* We don't care if this fails */
+ prealloc_page = shmem_alloc_page(gfp, info, idx);
+ if (prealloc_page) {
+ if (mem_cgroup_cache_charge(prealloc_page,
+ current->mm, GFP_KERNEL)) {
+ page_cache_release(prealloc_page);
+ prealloc_page = NULL;
+ }
+ }
+ }
}
+ error = 0;
spin_lock(&info->lock);
shmem_recalc_inode(inode);
@@ -1387,17 +1399,16 @@ repeat:
shmem_swp_unmap(entry);
sbinfo = SHMEM_SB(inode->i_sb);
if (sbinfo->max_blocks) {
- spin_lock(&sbinfo->stat_lock);
- if (sbinfo->free_blocks == 0 ||
+ if ((percpu_counter_compare(&sbinfo->used_blocks, sbinfo->max_blocks) > 0) ||
shmem_acct_block(info->flags)) {
- spin_unlock(&sbinfo->stat_lock);
spin_unlock(&info->lock);
error = -ENOSPC;
goto failed;
}
- sbinfo->free_blocks--;
+ percpu_counter_inc(&sbinfo->used_blocks);
+ spin_lock(&inode->i_lock);
inode->i_blocks += BLOCKS_PER_PAGE;
- spin_unlock(&sbinfo->stat_lock);
+ spin_unlock(&inode->i_lock);
} else if (shmem_acct_block(info->flags)) {
spin_unlock(&info->lock);
error = -ENOSPC;
@@ -1407,28 +1418,38 @@ repeat:
if (!filepage) {
int ret;
- spin_unlock(&info->lock);
- filepage = shmem_alloc_page(gfp, info, idx);
- if (!filepage) {
- shmem_unacct_blocks(info->flags, 1);
- shmem_free_blocks(inode, 1);
- error = -ENOMEM;
- goto failed;
- }
- SetPageSwapBacked(filepage);
+ if (!prealloc_page) {
+ spin_unlock(&info->lock);
+ filepage = shmem_alloc_page(gfp, info, idx);
+ if (!filepage) {
+ shmem_unacct_blocks(info->flags, 1);
+ shmem_free_blocks(inode, 1);
+ error = -ENOMEM;
+ goto failed;
+ }
+ SetPageSwapBacked(filepage);
- /* Precharge page while we can wait, compensate after */
- error = mem_cgroup_cache_charge(filepage, current->mm,
- GFP_KERNEL);
- if (error) {
- page_cache_release(filepage);
- shmem_unacct_blocks(info->flags, 1);
- shmem_free_blocks(inode, 1);
- filepage = NULL;
- goto failed;
+ /*
+ * Precharge page while we can wait, compensate
+ * after
+ */
+ error = mem_cgroup_cache_charge(filepage,
+ current->mm, GFP_KERNEL);
+ if (error) {
+ page_cache_release(filepage);
+ shmem_unacct_blocks(info->flags, 1);
+ shmem_free_blocks(inode, 1);
+ filepage = NULL;
+ goto failed;
+ }
+
+ spin_lock(&info->lock);
+ } else {
+ filepage = prealloc_page;
+ prealloc_page = NULL;
+ SetPageSwapBacked(filepage);
}
- spin_lock(&info->lock);
entry = shmem_swp_alloc(info, idx, sgp);
if (IS_ERR(entry))
error = PTR_ERR(entry);
@@ -1469,13 +1490,19 @@ repeat:
}
done:
*pagep = filepage;
- return 0;
+ error = 0;
+ goto out;
failed:
if (*pagep != filepage) {
unlock_page(filepage);
page_cache_release(filepage);
}
+out:
+ if (prealloc_page) {
+ mem_cgroup_uncharge_cache_page(prealloc_page);
+ page_cache_release(prealloc_page);
+ }
return error;
}
@@ -1791,17 +1818,16 @@ static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf)
buf->f_type = TMPFS_MAGIC;
buf->f_bsize = PAGE_CACHE_SIZE;
buf->f_namelen = NAME_MAX;
- spin_lock(&sbinfo->stat_lock);
if (sbinfo->max_blocks) {
buf->f_blocks = sbinfo->max_blocks;
- buf->f_bavail = buf->f_bfree = sbinfo->free_blocks;
+ buf->f_bavail = buf->f_bfree =
+ sbinfo->max_blocks - percpu_counter_sum(&sbinfo->used_blocks);
}
if (sbinfo->max_inodes) {
buf->f_files = sbinfo->max_inodes;
buf->f_ffree = sbinfo->free_inodes;
}
/* else leave those fields 0 like simple_statfs */
- spin_unlock(&sbinfo->stat_lock);
return 0;
}
@@ -2242,7 +2268,6 @@ static int shmem_remount_fs(struct super_block *sb, int *flags, char *data)
{
struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
struct shmem_sb_info config = *sbinfo;
- unsigned long blocks;
unsigned long inodes;
int error = -EINVAL;
@@ -2250,9 +2275,8 @@ static int shmem_remount_fs(struct super_block *sb, int *flags, char *data)
return error;
spin_lock(&sbinfo->stat_lock);
- blocks = sbinfo->max_blocks - sbinfo->free_blocks;
inodes = sbinfo->max_inodes - sbinfo->free_inodes;
- if (config.max_blocks < blocks)
+ if (percpu_counter_compare(&sbinfo->used_blocks, config.max_blocks) > 0)
goto out;
if (config.max_inodes < inodes)
goto out;
@@ -2269,7 +2293,6 @@ static int shmem_remount_fs(struct super_block *sb, int *flags, char *data)
error = 0;
sbinfo->max_blocks = config.max_blocks;
- sbinfo->free_blocks = config.max_blocks - blocks;
sbinfo->max_inodes = config.max_inodes;
sbinfo->free_inodes = config.max_inodes - inodes;
@@ -2344,7 +2367,7 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent)
#endif
spin_lock_init(&sbinfo->stat_lock);
- sbinfo->free_blocks = sbinfo->max_blocks;
+ percpu_counter_init(&sbinfo->used_blocks, 0);
sbinfo->free_inodes = sbinfo->max_inodes;
sb->s_maxbytes = SHMEM_MAX_BYTES;
@@ -2496,7 +2519,7 @@ static const struct super_operations shmem_ops = {
.remount_fs = shmem_remount_fs,
.show_options = shmem_show_options,
#endif
- .delete_inode = shmem_delete_inode,
+ .evict_inode = shmem_evict_inode,
.drop_inode = generic_delete_inode,
.put_super = shmem_put_super,
};
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