Merge branch 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull nowait read support from Al Viro:
"Support IOCB_NOWAIT for buffered reads and block devices"
* 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
block_dev: support RFW_NOWAIT on block device nodes
fs: support RWF_NOWAIT for buffered reads
fs: support IOCB_NOWAIT in generic_file_buffered_read
fs: pass iocb to do_generic_file_read
diff --git a/fs/aio.c b/fs/aio.c
index b5d69f2..5a24872 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1606,12 +1606,6 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
goto out_put_req;
}
- if ((req->common.ki_flags & IOCB_NOWAIT) &&
- !(req->common.ki_flags & IOCB_DIRECT)) {
- ret = -EOPNOTSUPP;
- goto out_put_req;
- }
-
ret = put_user(KIOCB_KEY, &user_iocb->aio_key);
if (unlikely(ret)) {
pr_debug("EFAULT: aio_key\n");
diff --git a/fs/block_dev.c b/fs/block_dev.c
index bb715b2..93d088f 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1740,6 +1740,8 @@ static int blkdev_open(struct inode * inode, struct file * filp)
*/
filp->f_flags |= O_LARGEFILE;
+ filp->f_mode |= FMODE_NOWAIT;
+
if (filp->f_flags & O_NDELAY)
filp->f_mode |= FMODE_NDELAY;
if (filp->f_flags & O_EXCL)
@@ -1892,6 +1894,9 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
if (iocb->ki_pos >= size)
return -ENOSPC;
+ if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT)
+ return -EOPNOTSUPP;
+
iov_iter_truncate(from, size - iocb->ki_pos);
blk_start_plug(&plug);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 74fd775..aafcc78 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1886,6 +1886,10 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
loff_t oldsize;
int clean_page = 0;
+ if (!(iocb->ki_flags & IOCB_DIRECT) &&
+ (iocb->ki_flags & IOCB_NOWAIT))
+ return -EOPNOTSUPP;
+
if (!inode_trylock(inode)) {
if (iocb->ki_flags & IOCB_NOWAIT)
return -EAGAIN;
@@ -3112,7 +3116,7 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
static int btrfs_file_open(struct inode *inode, struct file *filp)
{
- filp->f_mode |= FMODE_AIO_NOWAIT;
+ filp->f_mode |= FMODE_NOWAIT;
return generic_file_open(inode, filp);
}
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index da9c694..b1da660 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -223,6 +223,8 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
if (IS_DAX(inode))
return ext4_dax_write_iter(iocb, from);
#endif
+ if (!o_direct && (iocb->ki_flags & IOCB_NOWAIT))
+ return -EOPNOTSUPP;
if (!inode_trylock(inode)) {
if (iocb->ki_flags & IOCB_NOWAIT)
@@ -431,9 +433,7 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
return ret;
}
- /* Set the flags to support nowait AIO */
- filp->f_mode |= FMODE_AIO_NOWAIT;
-
+ filp->f_mode |= FMODE_NOWAIT;
return dquot_file_open(inode, filp);
}
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index ec3e44f..ebdd0bd 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -259,7 +259,11 @@ xfs_file_buffered_aio_read(
trace_xfs_file_buffered_read(ip, iov_iter_count(to), iocb->ki_pos);
- xfs_ilock(ip, XFS_IOLOCK_SHARED);
+ if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
+ if (iocb->ki_flags & IOCB_NOWAIT)
+ return -EAGAIN;
+ xfs_ilock(ip, XFS_IOLOCK_SHARED);
+ }
ret = generic_file_read_iter(iocb, to);
xfs_iunlock(ip, XFS_IOLOCK_SHARED);
@@ -636,6 +640,9 @@ xfs_file_buffered_aio_write(
int enospc = 0;
int iolock;
+ if (iocb->ki_flags & IOCB_NOWAIT)
+ return -EOPNOTSUPP;
+
write_retry:
iolock = XFS_IOLOCK_EXCL;
xfs_ilock(ip, iolock);
@@ -912,7 +919,7 @@ xfs_file_open(
return -EFBIG;
if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
return -EIO;
- file->f_mode |= FMODE_AIO_NOWAIT;
+ file->f_mode |= FMODE_NOWAIT;
return 0;
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index b4ae080..bc475df 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -148,8 +148,8 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
/* File was opened by fanotify and shouldn't generate fanotify events */
#define FMODE_NONOTIFY ((__force fmode_t)0x4000000)
-/* File is capable of returning -EAGAIN if AIO will block */
-#define FMODE_AIO_NOWAIT ((__force fmode_t)0x8000000)
+/* File is capable of returning -EAGAIN if I/O will block */
+#define FMODE_NOWAIT ((__force fmode_t)0x8000000)
/*
* Flag for rw_copy_check_uvector and compat_rw_copy_check_uvector
@@ -3194,7 +3194,7 @@ static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags)
return -EOPNOTSUPP;
if (flags & RWF_NOWAIT) {
- if (!(ki->ki_filp->f_mode & FMODE_AIO_NOWAIT))
+ if (!(ki->ki_filp->f_mode & FMODE_NOWAIT))
return -EOPNOTSUPP;
ki->ki_flags |= IOCB_NOWAIT;
}
diff --git a/mm/filemap.c b/mm/filemap.c
index 8c88e18..870971e 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1917,9 +1917,8 @@ static void shrink_readahead_size_eio(struct file *filp,
}
/**
- * do_generic_file_read - generic file read routine
- * @filp: the file to read
- * @ppos: current file position
+ * generic_file_buffered_read - generic file read routine
+ * @iocb: the iocb to read
* @iter: data destination
* @written: already copied
*
@@ -1929,12 +1928,14 @@ static void shrink_readahead_size_eio(struct file *filp,
* This is really ugly. But the goto's actually try to clarify some
* of the logic when it comes to error handling etc.
*/
-static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos,
+static ssize_t generic_file_buffered_read(struct kiocb *iocb,
struct iov_iter *iter, ssize_t written)
{
+ struct file *filp = iocb->ki_filp;
struct address_space *mapping = filp->f_mapping;
struct inode *inode = mapping->host;
struct file_ra_state *ra = &filp->f_ra;
+ loff_t *ppos = &iocb->ki_pos;
pgoff_t index;
pgoff_t last_index;
pgoff_t prev_index;
@@ -1967,6 +1968,8 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos,
page = find_get_page(mapping, index);
if (!page) {
+ if (iocb->ki_flags & IOCB_NOWAIT)
+ goto would_block;
page_cache_sync_readahead(mapping,
ra, filp,
index, last_index - index);
@@ -1980,6 +1983,11 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos,
index, last_index - index);
}
if (!PageUptodate(page)) {
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ put_page(page);
+ goto would_block;
+ }
+
/*
* See comment in do_read_cache_page on why
* wait_on_page_locked is used to avoid unnecessarily
@@ -2161,6 +2169,8 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos,
goto readpage;
}
+would_block:
+ error = -EAGAIN;
out:
ra->prev_pos = prev_index;
ra->prev_pos <<= PAGE_SHIFT;
@@ -2182,14 +2192,14 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos,
ssize_t
generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
{
- struct file *file = iocb->ki_filp;
- ssize_t retval = 0;
size_t count = iov_iter_count(iter);
+ ssize_t retval = 0;
if (!count)
goto out; /* skip atime */
if (iocb->ki_flags & IOCB_DIRECT) {
+ struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
loff_t size;
@@ -2230,7 +2240,7 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
goto out;
}
- retval = do_generic_file_read(file, &iocb->ki_pos, iter, retval);
+ retval = generic_file_buffered_read(iocb, iter, retval);
out:
return retval;
}
