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-rw-r--r--fs/ext2/dir.c94
1 files changed, 60 insertions, 34 deletions
diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index 14aa45316ad2..14292dba3a12 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -190,13 +190,20 @@ fail:
return false;
}
+/*
+ * Calls to ext2_get_page()/ext2_put_page() must be nested according to the
+ * rules documented in kmap_local_page()/kunmap_local().
+ *
+ * NOTE: ext2_find_entry() and ext2_dotdot() act as a call to ext2_get_page()
+ * and should be treated as a call to ext2_get_page() for nesting purposes.
+ */
static struct page * ext2_get_page(struct inode *dir, unsigned long n,
- int quiet)
+ int quiet, void **page_addr)
{
struct address_space *mapping = dir->i_mapping;
struct page *page = read_mapping_page(mapping, n, NULL);
if (!IS_ERR(page)) {
- kmap(page);
+ *page_addr = kmap_local_page(page);
if (unlikely(!PageChecked(page))) {
if (PageError(page) || !ext2_check_page(page, quiet))
goto fail;
@@ -205,7 +212,7 @@ static struct page * ext2_get_page(struct inode *dir, unsigned long n,
return page;
fail:
- ext2_put_page(page);
+ ext2_put_page(page, *page_addr);
return ERR_PTR(-EIO);
}
@@ -276,7 +283,7 @@ ext2_readdir(struct file *file, struct dir_context *ctx)
for ( ; n < npages; n++, offset = 0) {
char *kaddr, *limit;
ext2_dirent *de;
- struct page *page = ext2_get_page(inode, n, 0);
+ struct page *page = ext2_get_page(inode, n, 0, (void **)&kaddr);
if (IS_ERR(page)) {
ext2_error(sb, __func__,
@@ -285,7 +292,6 @@ ext2_readdir(struct file *file, struct dir_context *ctx)
ctx->pos += PAGE_SIZE - offset;
return PTR_ERR(page);
}
- kaddr = page_address(page);
if (unlikely(need_revalidate)) {
if (offset) {
offset = ext2_validate_entry(kaddr, offset, chunk_mask);
@@ -300,7 +306,7 @@ ext2_readdir(struct file *file, struct dir_context *ctx)
if (de->rec_len == 0) {
ext2_error(sb, __func__,
"zero-length directory entry");
- ext2_put_page(page);
+ ext2_put_page(page, kaddr);
return -EIO;
}
if (de->inode) {
@@ -312,13 +318,13 @@ ext2_readdir(struct file *file, struct dir_context *ctx)
if (!dir_emit(ctx, de->name, de->name_len,
le32_to_cpu(de->inode),
d_type)) {
- ext2_put_page(page);
+ ext2_put_page(page, kaddr);
return 0;
}
}
ctx->pos += ext2_rec_len_from_disk(de->rec_len);
}
- ext2_put_page(page);
+ ext2_put_page(page, kaddr);
}
return 0;
}
@@ -332,9 +338,16 @@ ext2_readdir(struct file *file, struct dir_context *ctx)
* Entry is guaranteed to be valid.
*
* On Success ext2_put_page() should be called on *res_page.
+ *
+ * NOTE: Calls to ext2_get_page()/ext2_put_page() must be nested according to
+ * the rules documented in kmap_local_page()/kunmap_local().
+ *
+ * ext2_find_entry() and ext2_dotdot() act as a call to ext2_get_page() and
+ * should be treated as a call to ext2_get_page() for nesting purposes.
*/
struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir,
- const struct qstr *child, struct page **res_page)
+ const struct qstr *child, struct page **res_page,
+ void **res_page_addr)
{
const char *name = child->name;
int namelen = child->len;
@@ -344,12 +357,14 @@ struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir,
struct page *page = NULL;
struct ext2_inode_info *ei = EXT2_I(dir);
ext2_dirent * de;
+ void *page_addr;
if (npages == 0)
goto out;
/* OFFSET_CACHE */
*res_page = NULL;
+ *res_page_addr = NULL;
start = ei->i_dir_start_lookup;
if (start >= npages)
@@ -357,25 +372,25 @@ struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir,
n = start;
do {
char *kaddr;
- page = ext2_get_page(dir, n, 0);
+ page = ext2_get_page(dir, n, 0, &page_addr);
if (IS_ERR(page))
return ERR_CAST(page);
- kaddr = page_address(page);
+ kaddr = page_addr;
de = (ext2_dirent *) kaddr;
kaddr += ext2_last_byte(dir, n) - reclen;
while ((char *) de <= kaddr) {
if (de->rec_len == 0) {
ext2_error(dir->i_sb, __func__,
"zero-length directory entry");
- ext2_put_page(page);
+ ext2_put_page(page, page_addr);
goto out;
}
if (ext2_match(namelen, name, de))
goto found;
de = ext2_next_entry(de);
}
- ext2_put_page(page);
+ ext2_put_page(page, page_addr);
if (++n >= npages)
n = 0;
@@ -393,6 +408,7 @@ out:
found:
*res_page = page;
+ *res_page_addr = page_addr;
ei->i_dir_start_lookup = n;
return de;
}
@@ -402,15 +418,24 @@ found:
* (as a parameter - p).
*
* On Success ext2_put_page() should be called on *p.
+ *
+ * NOTE: Calls to ext2_get_page()/ext2_put_page() must be nested according to
+ * the rules documented in kmap_local_page()/kunmap_local().
+ *
+ * ext2_find_entry() and ext2_dotdot() act as a call to ext2_get_page() and
+ * should be treated as a call to ext2_get_page() for nesting purposes.
*/
-struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p)
+struct ext2_dir_entry_2 *ext2_dotdot(struct inode *dir, struct page **p,
+ void **pa)
{
- struct page *page = ext2_get_page(dir, 0, 0);
+ void *page_addr;
+ struct page *page = ext2_get_page(dir, 0, 0, &page_addr);
ext2_dirent *de = NULL;
if (!IS_ERR(page)) {
- de = ext2_next_entry((ext2_dirent *) page_address(page));
+ de = ext2_next_entry((ext2_dirent *) page_addr);
*p = page;
+ *pa = page_addr;
}
return de;
}
@@ -419,13 +444,14 @@ int ext2_inode_by_name(struct inode *dir, const struct qstr *child, ino_t *ino)
{
struct ext2_dir_entry_2 *de;
struct page *page;
+ void *page_addr;
- de = ext2_find_entry(dir, child, &page);
+ de = ext2_find_entry(dir, child, &page, &page_addr);
if (IS_ERR(de))
return PTR_ERR(de);
*ino = le32_to_cpu(de->inode);
- ext2_put_page(page);
+ ext2_put_page(page, page_addr);
return 0;
}
@@ -434,12 +460,12 @@ static int ext2_prepare_chunk(struct page *page, loff_t pos, unsigned len)
return __block_write_begin(page, pos, len, ext2_get_block);
}
-/* Releases the page */
void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
- struct page *page, struct inode *inode, int update_times)
+ struct page *page, void *page_addr, struct inode *inode,
+ int update_times)
{
loff_t pos = page_offset(page) +
- (char *) de - (char *) page_address(page);
+ (char *) de - (char *) page_addr;
unsigned len = ext2_rec_len_from_disk(de->rec_len);
int err;
@@ -449,7 +475,6 @@ void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
de->inode = cpu_to_le32(inode->i_ino);
ext2_set_de_type(de, inode);
err = ext2_commit_chunk(page, pos, len);
- ext2_put_page(page);
if (update_times)
dir->i_mtime = dir->i_ctime = current_time(dir);
EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;
@@ -468,10 +493,10 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode)
unsigned reclen = EXT2_DIR_REC_LEN(namelen);
unsigned short rec_len, name_len;
struct page *page = NULL;
+ void *page_addr = NULL;
ext2_dirent * de;
unsigned long npages = dir_pages(dir);
unsigned long n;
- char *kaddr;
loff_t pos;
int err;
@@ -481,14 +506,15 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode)
* to protect that region.
*/
for (n = 0; n <= npages; n++) {
+ char *kaddr;
char *dir_end;
- page = ext2_get_page(dir, n, 0);
+ page = ext2_get_page(dir, n, 0, &page_addr);
err = PTR_ERR(page);
if (IS_ERR(page))
goto out;
lock_page(page);
- kaddr = page_address(page);
+ kaddr = page_addr;
dir_end = kaddr + ext2_last_byte(dir, n);
de = (ext2_dirent *)kaddr;
kaddr += PAGE_SIZE - reclen;
@@ -519,14 +545,14 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode)
de = (ext2_dirent *) ((char *) de + rec_len);
}
unlock_page(page);
- ext2_put_page(page);
+ ext2_put_page(page, page_addr);
}
BUG();
return -EINVAL;
got_it:
pos = page_offset(page) +
- (char*)de - (char*)page_address(page);
+ (char *)de - (char *)page_addr;
err = ext2_prepare_chunk(page, pos, rec_len);
if (err)
goto out_unlock;
@@ -546,7 +572,7 @@ got_it:
mark_inode_dirty(dir);
/* OFFSET_CACHE */
out_put:
- ext2_put_page(page);
+ ext2_put_page(page, page_addr);
out:
return err;
out_unlock:
@@ -556,7 +582,7 @@ out_unlock:
/*
* ext2_delete_entry deletes a directory entry by merging it with the
- * previous entry. Page is up-to-date. Releases the page.
+ * previous entry. Page is up-to-date.
*/
int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page )
{
@@ -594,7 +620,6 @@ int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page )
EXT2_I(inode)->i_flags &= ~EXT2_BTREE_FL;
mark_inode_dirty(inode);
out:
- ext2_put_page(page);
return err;
}
@@ -644,6 +669,7 @@ fail:
*/
int ext2_empty_dir (struct inode * inode)
{
+ void *page_addr = NULL;
struct page *page = NULL;
unsigned long i, npages = dir_pages(inode);
int dir_has_error = 0;
@@ -651,14 +677,14 @@ int ext2_empty_dir (struct inode * inode)
for (i = 0; i < npages; i++) {
char *kaddr;
ext2_dirent * de;
- page = ext2_get_page(inode, i, dir_has_error);
+ page = ext2_get_page(inode, i, dir_has_error, &page_addr);
if (IS_ERR(page)) {
dir_has_error = 1;
continue;
}
- kaddr = page_address(page);
+ kaddr = page_addr;
de = (ext2_dirent *)kaddr;
kaddr += ext2_last_byte(inode, i) - EXT2_DIR_REC_LEN(1);
@@ -684,12 +710,12 @@ int ext2_empty_dir (struct inode * inode)
}
de = ext2_next_entry(de);
}
- ext2_put_page(page);
+ ext2_put_page(page, page_addr);
}
return 1;
not_empty:
- ext2_put_page(page);
+ ext2_put_page(page, page_addr);
return 0;
}