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-rw-r--r--kernel/mm/shmem.c111
1 files changed, 61 insertions, 50 deletions
diff --git a/kernel/mm/shmem.c b/kernel/mm/shmem.c
index 47d536e59..ea5a70cfc 100644
--- a/kernel/mm/shmem.c
+++ b/kernel/mm/shmem.c
@@ -73,6 +73,8 @@ static struct vfsmount *shm_mnt;
#include <asm/uaccess.h>
#include <asm/pgtable.h>
+#include "internal.h"
+
#define BLOCKS_PER_PAGE (PAGE_CACHE_SIZE/512)
#define VM_ACCT(size) (PAGE_CACHE_ALIGN(size) >> PAGE_SHIFT)
@@ -542,6 +544,21 @@ void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
}
EXPORT_SYMBOL_GPL(shmem_truncate_range);
+static int shmem_getattr(struct vfsmount *mnt, struct dentry *dentry,
+ struct kstat *stat)
+{
+ struct inode *inode = dentry->d_inode;
+ struct shmem_inode_info *info = SHMEM_I(inode);
+
+ if (info->alloced - info->swapped != inode->i_mapping->nrpages) {
+ spin_lock(&info->lock);
+ shmem_recalc_inode(inode);
+ spin_unlock(&info->lock);
+ }
+ generic_fillattr(inode, stat);
+ return 0;
+}
+
static int shmem_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = d_inode(dentry);
@@ -569,12 +586,18 @@ static int shmem_setattr(struct dentry *dentry, struct iattr *attr)
i_size_write(inode, newsize);
inode->i_ctime = inode->i_mtime = CURRENT_TIME;
}
- if (newsize < oldsize) {
+ if (newsize <= oldsize) {
loff_t holebegin = round_up(newsize, PAGE_SIZE);
- unmap_mapping_range(inode->i_mapping, holebegin, 0, 1);
- shmem_truncate_range(inode, newsize, (loff_t)-1);
+ if (oldsize > holebegin)
+ unmap_mapping_range(inode->i_mapping,
+ holebegin, 0, 1);
+ if (info->alloced)
+ shmem_truncate_range(inode,
+ newsize, (loff_t)-1);
/* unmap again to remove racily COWed private pages */
- unmap_mapping_range(inode->i_mapping, holebegin, 0, 1);
+ if (oldsize > holebegin)
+ unmap_mapping_range(inode->i_mapping,
+ holebegin, 0, 1);
}
}
@@ -597,8 +620,7 @@ static void shmem_evict_inode(struct inode *inode)
list_del_init(&info->swaplist);
mutex_unlock(&shmem_swaplist_mutex);
}
- } else
- kfree(info->symlink);
+ }
simple_xattrs_free(&info->xattrs);
WARN_ON(inode->i_blocks);
@@ -820,14 +842,14 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
list_add_tail(&info->swaplist, &shmem_swaplist);
if (add_to_swap_cache(page, swap, GFP_ATOMIC) == 0) {
- swap_shmem_alloc(swap);
- shmem_delete_from_page_cache(page, swp_to_radix_entry(swap));
-
spin_lock(&info->lock);
- info->swapped++;
shmem_recalc_inode(inode);
+ info->swapped++;
spin_unlock(&info->lock);
+ swap_shmem_alloc(swap);
+ shmem_delete_from_page_cache(page, swp_to_radix_entry(swap));
+
mutex_unlock(&shmem_swaplist_mutex);
BUG_ON(page_mapped(page));
swap_writepage(page, wbc);
@@ -1008,7 +1030,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
*/
oldpage = newpage;
} else {
- mem_cgroup_migrate(oldpage, newpage, true);
+ mem_cgroup_replace_page(oldpage, newpage);
lru_cache_add_anon(newpage);
*pagep = newpage;
}
@@ -1055,7 +1077,7 @@ repeat:
if (sgp != SGP_WRITE && sgp != SGP_FALLOC &&
((loff_t)index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) {
error = -EINVAL;
- goto failed;
+ goto unlock;
}
if (page && sgp == SGP_WRITE)
@@ -1223,11 +1245,15 @@ clear:
/* Perhaps the file has been truncated since we checked */
if (sgp != SGP_WRITE && sgp != SGP_FALLOC &&
((loff_t)index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) {
+ if (alloced) {
+ ClearPageDirty(page);
+ delete_from_page_cache(page);
+ spin_lock(&info->lock);
+ shmem_recalc_inode(inode);
+ spin_unlock(&info->lock);
+ }
error = -EINVAL;
- if (alloced)
- goto trunc;
- else
- goto failed;
+ goto unlock;
}
*pagep = page;
return 0;
@@ -1235,23 +1261,13 @@ clear:
/*
* Error recovery.
*/
-trunc:
- info = SHMEM_I(inode);
- ClearPageDirty(page);
- delete_from_page_cache(page);
- spin_lock(&info->lock);
- info->alloced--;
- inode->i_blocks -= BLOCKS_PER_PAGE;
- spin_unlock(&info->lock);
decused:
- sbinfo = SHMEM_SB(inode->i_sb);
if (sbinfo->max_blocks)
percpu_counter_add(&sbinfo->used_blocks, -1);
unacct:
shmem_unacct_blocks(info->flags, 1);
failed:
- if (swap.val && error != -EINVAL &&
- !shmem_confirm_swap(mapping, index, swap))
+ if (swap.val && !shmem_confirm_swap(mapping, index, swap))
error = -EEXIST;
unlock:
if (page) {
@@ -2445,8 +2461,8 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
info = SHMEM_I(inode);
inode->i_size = len-1;
if (len <= SHORT_SYMLINK_LEN) {
- info->symlink = kmemdup(symname, len, GFP_KERNEL);
- if (!info->symlink) {
+ inode->i_link = kmemdup(symname, len, GFP_KERNEL);
+ if (!inode->i_link) {
iput(inode);
return -ENOMEM;
}
@@ -2474,30 +2490,23 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
return 0;
}
-static void *shmem_follow_short_symlink(struct dentry *dentry, struct nameidata *nd)
-{
- nd_set_link(nd, SHMEM_I(d_inode(dentry))->symlink);
- return NULL;
-}
-
-static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *shmem_follow_link(struct dentry *dentry, void **cookie)
{
struct page *page = NULL;
int error = shmem_getpage(d_inode(dentry), 0, &page, SGP_READ, NULL);
- nd_set_link(nd, error ? ERR_PTR(error) : kmap(page));
- if (page)
- unlock_page(page);
- return page;
+ if (error)
+ return ERR_PTR(error);
+ unlock_page(page);
+ *cookie = page;
+ return kmap(page);
}
-static void shmem_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
+static void shmem_put_link(struct inode *unused, void *cookie)
{
- if (!IS_ERR(nd_get_link(nd))) {
- struct page *page = cookie;
- kunmap(page);
- mark_page_accessed(page);
- page_cache_release(page);
- }
+ struct page *page = cookie;
+ kunmap(page);
+ mark_page_accessed(page);
+ page_cache_release(page);
}
#ifdef CONFIG_TMPFS_XATTR
@@ -2642,7 +2651,7 @@ static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
static const struct inode_operations shmem_short_symlink_operations = {
.readlink = generic_readlink,
- .follow_link = shmem_follow_short_symlink,
+ .follow_link = simple_follow_link,
#ifdef CONFIG_TMPFS_XATTR
.setxattr = shmem_setxattr,
.getxattr = shmem_getxattr,
@@ -3072,6 +3081,7 @@ static struct inode *shmem_alloc_inode(struct super_block *sb)
static void shmem_destroy_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
+ kfree(inode->i_link);
kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode));
}
@@ -3128,6 +3138,7 @@ static const struct file_operations shmem_file_operations = {
};
static const struct inode_operations shmem_inode_operations = {
+ .getattr = shmem_getattr,
.setattr = shmem_setattr,
#ifdef CONFIG_TMPFS_XATTR
.setxattr = shmem_setxattr,
@@ -3369,8 +3380,8 @@ put_path:
* shmem_kernel_file_setup - get an unlinked file living in tmpfs which must be
* kernel internal. There will be NO LSM permission checks against the
* underlying inode. So users of this interface must do LSM checks at a
- * higher layer. The one user is the big_key implementation. LSM checks
- * are provided at the key level rather than the inode level.
+ * higher layer. The users are the big_key and shm implementations. LSM
+ * checks are provided at the key or shm level rather than the inode.
* @name: name for dentry (to be seen in /proc/<pid>/maps
* @size: size to be set for the file
* @flags: VM_NORESERVE suppresses pre-accounting of the entire object size