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authorMatthew Wilcox (Oracle) <willy@infradead.org>2021-02-24 12:02:22 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-24 13:38:28 -0800
commit4612aeef09ec492ca5877e06f0dbac5383da5e88 (patch)
tree08274b9b55376388802c8a9827857e1a9fb13a83 /mm/filemap.c
parentf253e1854ce8441eefe98f193def2c477a017d81 (diff)
mm/filemap: convert filemap_update_page to return an errno
Use AOP_TRUNCATED_PAGE to indicate that no error occurred, but the page we looked up is no longer valid. In this case, the reference to the page will have been removed; if we hit any other error, the caller will release the reference. Link: https://lkml.kernel.org/r/20210122160140.223228-12-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/filemap.c')
-rw-r--r--mm/filemap.c38
1 files changed, 17 insertions, 21 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index c0e5aff274f3..67c4df82aa41 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2233,24 +2233,21 @@ static int filemap_read_page(struct file *file, struct address_space *mapping,
return error;
}
-static struct page *filemap_update_page(struct kiocb *iocb, struct file *filp,
- struct iov_iter *iter, struct page *page, loff_t pos,
- loff_t count)
+static int filemap_update_page(struct kiocb *iocb,
+ struct address_space *mapping, struct iov_iter *iter,
+ struct page *page, loff_t pos, loff_t count)
{
- struct address_space *mapping = filp->f_mapping;
struct inode *inode = mapping->host;
int error;
if (iocb->ki_flags & IOCB_WAITQ) {
error = lock_page_async(page, iocb->ki_waitq);
- if (error) {
- put_page(page);
- return ERR_PTR(error);
- }
+ if (error)
+ return error;
} else {
if (!trylock_page(page)) {
put_and_wait_on_page_locked(page, TASK_KILLABLE);
- return NULL;
+ return AOP_TRUNCATED_PAGE;
}
}
@@ -2269,25 +2266,21 @@ static struct page *filemap_update_page(struct kiocb *iocb, struct file *filp,
goto readpage;
uptodate:
unlock_page(page);
- return page;
+ return 0;
readpage:
if (iocb->ki_flags & (IOCB_NOIO | IOCB_NOWAIT | IOCB_WAITQ)) {
unlock_page(page);
- put_page(page);
- return ERR_PTR(-EAGAIN);
+ return -EAGAIN;
}
error = filemap_read_page(iocb->ki_filp, mapping, page);
- if (!error)
- return page;
- put_page(page);
if (error == AOP_TRUNCATED_PAGE)
- return NULL;
- return ERR_PTR(error);
+ put_page(page);
+ return error;
truncated:
unlock_page(page);
put_page(page);
- return NULL;
+ return AOP_TRUNCATED_PAGE;
}
static int filemap_create_page(struct file *file,
@@ -2381,11 +2374,12 @@ got_pages:
goto err;
}
- page = filemap_update_page(iocb, filp, iter, page,
+ err = filemap_update_page(iocb, mapping, iter, page,
pg_pos, pg_count);
- if (IS_ERR_OR_NULL(page)) {
+ if (err) {
+ if (err < 0)
+ put_page(page);
pvec->nr--;
- err = PTR_ERR_OR_ZERO(page);
}
}
}
@@ -2393,6 +2387,8 @@ got_pages:
err:
if (likely(pvec->nr))
return 0;
+ if (err == AOP_TRUNCATED_PAGE)
+ goto find_page;
if (err)
return err;
/*