On Wed 11-11-20 12:55:30, ira.weiny@xxxxxxxxx wrote: > 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> Thanks. Good cleanup. I've added it to my tree. Honza > > --- > > 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 > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
