Commit c4c2416a authored by Gang He's avatar Gang He Committed by Linus Torvalds

ocfs2: nowait aio support

Return EAGAIN if any of the following checks fail for direct I/O:

 - Cannot get the related locks immediately

 - Blocks are not allocated at the write location, it will trigger block
   allocation and block IO operations.

[ghe@suse.com: v4]
  Link: http://lkml.kernel.org/r/1516007283-29932-4-git-send-email-ghe@suse.com
[ghe@suse.com: v2]
  Link: http://lkml.kernel.org/r/1511944612-9629-4-git-send-email-ghe@suse.com
Link: http://lkml.kernel.org/r/1511775987-841-4-git-send-email-ghe@suse.comSigned-off-by: default avatarGang He <ghe@suse.com>
Reviewed-by: default avatarAlex Chen <alex.chen@huawei.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ac604d3c
......@@ -1958,7 +1958,7 @@ int ocfs2_readdir(struct file *file, struct dir_context *ctx)
trace_ocfs2_readdir((unsigned long long)OCFS2_I(inode)->ip_blkno);
error = ocfs2_inode_lock_atime(inode, file->f_path.mnt, &lock_level);
error = ocfs2_inode_lock_atime(inode, file->f_path.mnt, &lock_level, 1);
if (lock_level && error >= 0) {
/* We release EX lock which used to update atime
* and get PR lock again to reduce contention
......
......@@ -2546,13 +2546,18 @@ int ocfs2_inode_lock_with_page(struct inode *inode,
int ocfs2_inode_lock_atime(struct inode *inode,
struct vfsmount *vfsmnt,
int *level)
int *level, int wait)
{
int ret;
ret = ocfs2_inode_lock(inode, NULL, 0);
if (wait)
ret = ocfs2_inode_lock(inode, NULL, 0);
else
ret = ocfs2_try_inode_lock(inode, NULL, 0);
if (ret < 0) {
mlog_errno(ret);
if (ret != -EAGAIN)
mlog_errno(ret);
return ret;
}
......@@ -2564,9 +2569,14 @@ int ocfs2_inode_lock_atime(struct inode *inode,
struct buffer_head *bh = NULL;
ocfs2_inode_unlock(inode, 0);
ret = ocfs2_inode_lock(inode, &bh, 1);
if (wait)
ret = ocfs2_inode_lock(inode, &bh, 1);
else
ret = ocfs2_try_inode_lock(inode, &bh, 1);
if (ret < 0) {
mlog_errno(ret);
if (ret != -EAGAIN)
mlog_errno(ret);
return ret;
}
*level = 1;
......
......@@ -146,7 +146,7 @@ int ocfs2_try_open_lock(struct inode *inode, int write);
void ocfs2_open_unlock(struct inode *inode);
int ocfs2_inode_lock_atime(struct inode *inode,
struct vfsmount *vfsmnt,
int *level);
int *level, int wait);
int ocfs2_inode_lock_full_nested(struct inode *inode,
struct buffer_head **ret_bh,
int ex,
......
......@@ -140,6 +140,8 @@ static int ocfs2_file_open(struct inode *inode, struct file *file)
spin_unlock(&oi->ip_lock);
}
file->f_mode |= FMODE_NOWAIT;
leave:
return status;
}
......@@ -2132,12 +2134,12 @@ static int ocfs2_prepare_inode_for_refcount(struct inode *inode,
}
static int ocfs2_prepare_inode_for_write(struct file *file,
loff_t pos,
size_t count)
loff_t pos, size_t count, int wait)
{
int ret = 0, meta_level = 0;
int ret = 0, meta_level = 0, overwrite_io = 0;
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = d_inode(dentry);
struct buffer_head *di_bh = NULL;
loff_t end;
/*
......@@ -2145,13 +2147,40 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
* if we need to make modifications here.
*/
for(;;) {
ret = ocfs2_inode_lock(inode, NULL, meta_level);
if (wait)
ret = ocfs2_inode_lock(inode, NULL, meta_level);
else
ret = ocfs2_try_inode_lock(inode,
overwrite_io ? NULL : &di_bh, meta_level);
if (ret < 0) {
meta_level = -1;
mlog_errno(ret);
if (ret != -EAGAIN)
mlog_errno(ret);
goto out;
}
/*
* Check if IO will overwrite allocated blocks in case
* IOCB_NOWAIT flag is set.
*/
if (!wait && !overwrite_io) {
overwrite_io = 1;
if (!down_read_trylock(&OCFS2_I(inode)->ip_alloc_sem)) {
ret = -EAGAIN;
goto out_unlock;
}
ret = ocfs2_overwrite_io(inode, di_bh, pos, count);
brelse(di_bh);
di_bh = NULL;
up_read(&OCFS2_I(inode)->ip_alloc_sem);
if (ret < 0) {
if (ret != -EAGAIN)
mlog_errno(ret);
goto out_unlock;
}
}
/* Clear suid / sgid if necessary. We do this here
* instead of later in the write path because
* remove_suid() calls ->setattr without any hint that
......@@ -2199,7 +2228,9 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
out_unlock:
trace_ocfs2_prepare_inode_for_write(OCFS2_I(inode)->ip_blkno,
pos, count);
pos, count, wait);
brelse(di_bh);
if (meta_level >= 0)
ocfs2_inode_unlock(inode, meta_level);
......@@ -2211,7 +2242,7 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
struct iov_iter *from)
{
int direct_io, rw_level;
int rw_level;
ssize_t written = 0;
ssize_t ret;
size_t count = iov_iter_count(from);
......@@ -2223,6 +2254,8 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
void *saved_ki_complete = NULL;
int append_write = ((iocb->ki_pos + count) >=
i_size_read(inode) ? 1 : 0);
int direct_io = iocb->ki_flags & IOCB_DIRECT ? 1 : 0;
int nowait = iocb->ki_flags & IOCB_NOWAIT ? 1 : 0;
trace_ocfs2_file_aio_write(inode, file, file->f_path.dentry,
(unsigned long long)OCFS2_I(inode)->ip_blkno,
......@@ -2230,12 +2263,17 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
file->f_path.dentry->d_name.name,
(unsigned int)from->nr_segs); /* GRRRRR */
if (!direct_io && nowait)
return -EOPNOTSUPP;
if (count == 0)
return 0;
direct_io = iocb->ki_flags & IOCB_DIRECT ? 1 : 0;
inode_lock(inode);
if (nowait) {
if (!inode_trylock(inode))
return -EAGAIN;
} else
inode_lock(inode);
/*
* Concurrent O_DIRECT writes are allowed with
......@@ -2244,9 +2282,13 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
*/
rw_level = (!direct_io || full_coherency || append_write);
ret = ocfs2_rw_lock(inode, rw_level);
if (nowait)
ret = ocfs2_try_rw_lock(inode, rw_level);
else
ret = ocfs2_rw_lock(inode, rw_level);
if (ret < 0) {
mlog_errno(ret);
if (ret != -EAGAIN)
mlog_errno(ret);
goto out_mutex;
}
......@@ -2260,9 +2302,13 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
* other nodes to drop their caches. Buffered I/O
* already does this in write_begin().
*/
ret = ocfs2_inode_lock(inode, NULL, 1);
if (nowait)
ret = ocfs2_try_inode_lock(inode, NULL, 1);
else
ret = ocfs2_inode_lock(inode, NULL, 1);
if (ret < 0) {
mlog_errno(ret);
if (ret != -EAGAIN)
mlog_errno(ret);
goto out;
}
......@@ -2277,9 +2323,10 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
}
count = ret;
ret = ocfs2_prepare_inode_for_write(file, iocb->ki_pos, count);
ret = ocfs2_prepare_inode_for_write(file, iocb->ki_pos, count, !nowait);
if (ret < 0) {
mlog_errno(ret);
if (ret != -EAGAIN)
mlog_errno(ret);
goto out;
}
......@@ -2355,6 +2402,8 @@ static ssize_t ocfs2_file_read_iter(struct kiocb *iocb,
int ret = 0, rw_level = -1, lock_level = 0;
struct file *filp = iocb->ki_filp;
struct inode *inode = file_inode(filp);
int direct_io = iocb->ki_flags & IOCB_DIRECT ? 1 : 0;
int nowait = iocb->ki_flags & IOCB_NOWAIT ? 1 : 0;
trace_ocfs2_file_aio_read(inode, filp, filp->f_path.dentry,
(unsigned long long)OCFS2_I(inode)->ip_blkno,
......@@ -2369,14 +2418,22 @@ static ssize_t ocfs2_file_read_iter(struct kiocb *iocb,
goto bail;
}
if (!direct_io && nowait)
return -EOPNOTSUPP;
/*
* buffered reads protect themselves in ->readpage(). O_DIRECT reads
* need locks to protect pending reads from racing with truncate.
*/
if (iocb->ki_flags & IOCB_DIRECT) {
ret = ocfs2_rw_lock(inode, 0);
if (direct_io) {
if (nowait)
ret = ocfs2_try_rw_lock(inode, 0);
else
ret = ocfs2_rw_lock(inode, 0);
if (ret < 0) {
mlog_errno(ret);
if (ret != -EAGAIN)
mlog_errno(ret);
goto bail;
}
rw_level = 0;
......@@ -2393,9 +2450,11 @@ static ssize_t ocfs2_file_read_iter(struct kiocb *iocb,
* like i_size. This allows the checks down below
* generic_file_aio_read() a chance of actually working.
*/
ret = ocfs2_inode_lock_atime(inode, filp->f_path.mnt, &lock_level);
ret = ocfs2_inode_lock_atime(inode, filp->f_path.mnt, &lock_level,
!nowait);
if (ret < 0) {
mlog_errno(ret);
if (ret != -EAGAIN)
mlog_errno(ret);
goto bail;
}
ocfs2_inode_unlock(inode, lock_level);
......
......@@ -184,7 +184,7 @@ int ocfs2_mmap(struct file *file, struct vm_area_struct *vma)
int ret = 0, lock_level = 0;
ret = ocfs2_inode_lock_atime(file_inode(file),
file->f_path.mnt, &lock_level);
file->f_path.mnt, &lock_level, 1);
if (ret < 0) {
mlog_errno(ret);
goto out;
......
......@@ -1449,20 +1449,22 @@ DEFINE_OCFS2_ULL_ULL_ULL_EVENT(ocfs2_remove_inode_range);
TRACE_EVENT(ocfs2_prepare_inode_for_write,
TP_PROTO(unsigned long long ino, unsigned long long saved_pos,
unsigned long count),
TP_ARGS(ino, saved_pos, count),
unsigned long count, int wait),
TP_ARGS(ino, saved_pos, count, wait),
TP_STRUCT__entry(
__field(unsigned long long, ino)
__field(unsigned long long, saved_pos)
__field(unsigned long, count)
__field(int, wait)
),
TP_fast_assign(
__entry->ino = ino;
__entry->saved_pos = saved_pos;
__entry->count = count;
__entry->wait = wait;
),
TP_printk("%llu %llu %lu", __entry->ino,
__entry->saved_pos, __entry->count)
TP_printk("%llu %llu %lu %d", __entry->ino,
__entry->saved_pos, __entry->count, __entry->wait)
);
DEFINE_OCFS2_INT_EVENT(generic_file_aio_read_ret);
......
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