From: Ira Weiny <ira.weiny@xxxxxxxxx> There are 3 places in namei.c where the equivalent of ext2_put_page() is open coded on a page which was returned from the ext2_get_page() call [through the use of ext2_find_entry() and ext2_dotdot()]. Move ext2_get_page() and ext2_put_page() to ext2.h in order to help clarify the use of the get/put and then use ext2_put_page() in namei.c Also add a comment regarding the proper way to release the page returned from ext2_find_entry() and ext2_dotdot(). Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> --- This was originally part of the kmap_thread() series here: https://lore.kernel.org/lkml/20201009195033.3208459-37-ira.weiny@xxxxxxxxx/ But this is really a valid clean up regardless of the kmap_thread[local]() changes. --- fs/ext2/dir.c | 33 ++++++++------------------------- fs/ext2/ext2.h | 27 +++++++++++++++++++++++++++ fs/ext2/namei.c | 15 +++++---------- 3 files changed, 40 insertions(+), 35 deletions(-) diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c index 70355ab6740e..8acd77a66ff4 100644 --- a/fs/ext2/dir.c +++ b/fs/ext2/dir.c @@ -66,12 +66,6 @@ static inline unsigned ext2_chunk_size(struct inode *inode) return inode->i_sb->s_blocksize; } -static inline void ext2_put_page(struct page *page) -{ - kunmap(page); - put_page(page); -} - /* * Return the offset into page `page_nr' of the last valid * byte in that page, plus one. @@ -196,25 +190,6 @@ static bool ext2_check_page(struct page *page, int quiet) return false; } -static struct page * ext2_get_page(struct inode *dir, unsigned long n, - int quiet) -{ - struct address_space *mapping = dir->i_mapping; - struct page *page = read_mapping_page(mapping, n, NULL); - if (!IS_ERR(page)) { - kmap(page); - if (unlikely(!PageChecked(page))) { - if (PageError(page) || !ext2_check_page(page, quiet)) - goto fail; - } - } - return page; - -fail: - ext2_put_page(page); - return ERR_PTR(-EIO); -} - /* * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure. * @@ -336,6 +311,8 @@ ext2_readdir(struct file *file, struct dir_context *ctx) * returns the page in which the entry was found (as a parameter - res_page), * and the entry itself. Page is returned mapped and unlocked. * Entry is guaranteed to be valid. + * + * On Success ext2_put_page() should be called on *res_page. */ struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir, const struct qstr *child, struct page **res_page) @@ -401,6 +378,12 @@ struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir, return de; } +/** + * Return the '..' directory entry and the page in which the entry was found + * (as a parameter - p). + * + * On Success ext2_put_page() should be called on *p. + */ struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p) { struct page *page = ext2_get_page(dir, 0, 0); diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h index 5136b7289e8d..b4403f96858b 100644 --- a/fs/ext2/ext2.h +++ b/fs/ext2/ext2.h @@ -16,6 +16,8 @@ #include <linux/blockgroup_lock.h> #include <linux/percpu_counter.h> #include <linux/rbtree.h> +#include <linux/mm.h> +#include <linux/highmem.h> /* XXX Here for now... not interested in restructing headers JUST now */ @@ -745,6 +747,31 @@ extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *); extern int ext2_empty_dir (struct inode *); extern struct ext2_dir_entry_2 * ext2_dotdot (struct inode *, struct page **); extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, struct inode *, int); +static inline void ext2_put_page(struct page *page) +{ + kunmap(page); + put_page(page); +} + +static inline struct page * ext2_get_page(struct inode *dir, unsigned long n, + int quiet) +{ + struct address_space *mapping = dir->i_mapping; + struct page *page = read_mapping_page(mapping, n, NULL); + if (!IS_ERR(page)) { + kmap(page); + if (unlikely(!PageChecked(page))) { + if (PageError(page) || !ext2_check_page(page, quiet)) + goto fail; + } + } + return page; + +fail: + ext2_put_page(page); + return ERR_PTR(-EIO); +} + /* ialloc.c */ extern struct inode * ext2_new_inode (struct inode *, umode_t, const struct qstr *); diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c index 5bf2c145643b..ea980f1e2e99 100644 --- a/fs/ext2/namei.c +++ b/fs/ext2/namei.c @@ -389,23 +389,18 @@ static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry, if (dir_de) { if (old_dir != new_dir) ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0); - else { - kunmap(dir_page); - put_page(dir_page); - } + else + ext2_put_page(dir_page); inode_dec_link_count(old_dir); } return 0; out_dir: - if (dir_de) { - kunmap(dir_page); - put_page(dir_page); - } + if (dir_de) + ext2_put_page(dir_page); out_old: - kunmap(old_page); - put_page(old_page); + ext2_put_page(old_page); out: return err; } -- 2.28.0.rc0.12.gb6a658bd00c9
