| Message ID | 1514455665-16325-4-git-send-email-ghe@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Gang, On 2017/12/28 18:07, Gang He wrote: > Return -EAGAIN if any of the following checks fail for > direct I/O with nowait flag: > Can not get the related locks immediately, > Blocks are not allocated at the write location, it will trigger > block allocation, this will block IO operations. > > Signed-off-by: Gang He <ghe@suse.com> > --- > fs/ocfs2/dir.c | 2 +- > fs/ocfs2/dlmglue.c | 20 ++++++++--- > fs/ocfs2/dlmglue.h | 2 +- > fs/ocfs2/file.c | 95 +++++++++++++++++++++++++++++++++++++++----------- > fs/ocfs2/mmap.c | 2 +- > fs/ocfs2/ocfs2_trace.h | 10 +++--- > 6 files changed, 99 insertions(+), 32 deletions(-) > > diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c > index febe631..ea50901 100644 > --- a/fs/ocfs2/dir.c > +++ b/fs/ocfs2/dir.c > @@ -1957,7 +1957,7 @@ 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 > diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c > index a68efa3..07e169f 100644 > --- a/fs/ocfs2/dlmglue.c > +++ b/fs/ocfs2/dlmglue.c > @@ -2515,13 +2515,18 @@ 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; > } > > @@ -2533,9 +2538,14 @@ 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; > diff --git a/fs/ocfs2/dlmglue.h b/fs/ocfs2/dlmglue.h > index 05910fc..c83dbb5 100644 > --- a/fs/ocfs2/dlmglue.h > +++ b/fs/ocfs2/dlmglue.h > @@ -123,7 +123,7 @@ void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res *lockres, > 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, > diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c > index a1d0510..caef9b1 100644 > --- a/fs/ocfs2/file.c > +++ b/fs/ocfs2/file.c > @@ -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); I think we only need check the nowait here because we already check if the 'IOCB_DIRECT' flag and the 'IOCB_NOWAIT' flag are both set in the front of this function. > + if (direct_io && 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 (direct_io && 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 +2402,7 @@ 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 nowait = iocb->ki_flags & IOCB_NOWAIT ? 1 : 0; > Here should we check if the 'IOCB_DIRECT' flag and the 'IOCB_NOWAIT' flag are both set? Thanks, Alex > trace_ocfs2_file_aio_read(inode, filp, filp->f_path.dentry, > (unsigned long long)OCFS2_I(inode)->ip_blkno, > @@ -2374,9 +2422,14 @@ static ssize_t ocfs2_file_read_iter(struct kiocb *iocb, > * need locks to protect pending reads from racing with truncate. > */ > if (iocb->ki_flags & IOCB_DIRECT) { > - ret = ocfs2_rw_lock(inode, 0); > + 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 +2446,11 @@ 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); > diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c > index 098f5c7..fb9a20e 100644 > --- a/fs/ocfs2/mmap.c > +++ b/fs/ocfs2/mmap.c > @@ -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; > diff --git a/fs/ocfs2/ocfs2_trace.h b/fs/ocfs2/ocfs2_trace.h > index a0b5d00..e2a11aa 100644 > --- a/fs/ocfs2/ocfs2_trace.h > +++ b/fs/ocfs2/ocfs2_trace.h > @@ -1449,20 +1449,22 @@ > > 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); >
Hi Alex, >>> > Hi Gang, > > On 2017/12/28 18:07, Gang He wrote: >> Return -EAGAIN if any of the following checks fail for >> direct I/O with nowait flag: >> Can not get the related locks immediately, >> Blocks are not allocated at the write location, it will trigger >> block allocation, this will block IO operations. >> >> Signed-off-by: Gang He <ghe@suse.com> >> --- >> fs/ocfs2/dir.c | 2 +- >> fs/ocfs2/dlmglue.c | 20 ++++++++--- >> fs/ocfs2/dlmglue.h | 2 +- >> fs/ocfs2/file.c | 95 +++++++++++++++++++++++++++++++++++++++----------- >> fs/ocfs2/mmap.c | 2 +- >> fs/ocfs2/ocfs2_trace.h | 10 +++--- >> 6 files changed, 99 insertions(+), 32 deletions(-) >> >> diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c >> index febe631..ea50901 100644 >> --- a/fs/ocfs2/dir.c >> +++ b/fs/ocfs2/dir.c >> @@ -1957,7 +1957,7 @@ 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 >> diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c >> index a68efa3..07e169f 100644 >> --- a/fs/ocfs2/dlmglue.c >> +++ b/fs/ocfs2/dlmglue.c >> @@ -2515,13 +2515,18 @@ 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; >> } >> >> @@ -2533,9 +2538,14 @@ 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; >> diff --git a/fs/ocfs2/dlmglue.h b/fs/ocfs2/dlmglue.h >> index 05910fc..c83dbb5 100644 >> --- a/fs/ocfs2/dlmglue.h >> +++ b/fs/ocfs2/dlmglue.h >> @@ -123,7 +123,7 @@ void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res > *lockres, >> 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, >> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c >> index a1d0510..caef9b1 100644 >> --- a/fs/ocfs2/file.c >> +++ b/fs/ocfs2/file.c >> @@ -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); > I think we only need check the nowait here because we already check if the > 'IOCB_DIRECT' > flag and the 'IOCB_NOWAIT' flag are both set in the front of this function. Yes. > >> + if (direct_io && 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 (direct_io && 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 +2402,7 @@ 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 nowait = iocb->ki_flags & IOCB_NOWAIT ? 1 : 0; >> > Here should we check if the 'IOCB_DIRECT' flag and the 'IOCB_NOWAIT' flag > are both set? Ok, I will look at the code again, make the code style consistent. Thanks Gang > > Thanks, > Alex > >> trace_ocfs2_file_aio_read(inode, filp, filp->f_path.dentry, >> (unsigned long long)OCFS2_I(inode)->ip_blkno, >> @@ -2374,9 +2422,14 @@ static ssize_t ocfs2_file_read_iter(struct kiocb > *iocb, >> * need locks to protect pending reads from racing with truncate. >> */ >> if (iocb->ki_flags & IOCB_DIRECT) { >> - ret = ocfs2_rw_lock(inode, 0); >> + 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 +2446,11 @@ 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); >> diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c >> index 098f5c7..fb9a20e 100644 >> --- a/fs/ocfs2/mmap.c >> +++ b/fs/ocfs2/mmap.c >> @@ -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; >> diff --git a/fs/ocfs2/ocfs2_trace.h b/fs/ocfs2/ocfs2_trace.h >> index a0b5d00..e2a11aa 100644 >> --- a/fs/ocfs2/ocfs2_trace.h >> +++ b/fs/ocfs2/ocfs2_trace.h >> @@ -1449,20 +1449,22 @@ >> >> 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); >>
diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c index febe631..ea50901 100644 --- a/fs/ocfs2/dir.c +++ b/fs/ocfs2/dir.c @@ -1957,7 +1957,7 @@ 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 diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c index a68efa3..07e169f 100644 --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -2515,13 +2515,18 @@ 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; } @@ -2533,9 +2538,14 @@ 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; diff --git a/fs/ocfs2/dlmglue.h b/fs/ocfs2/dlmglue.h index 05910fc..c83dbb5 100644 --- a/fs/ocfs2/dlmglue.h +++ b/fs/ocfs2/dlmglue.h @@ -123,7 +123,7 @@ void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res *lockres, 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, diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index a1d0510..caef9b1 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -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 (direct_io && 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 (direct_io && 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 +2402,7 @@ 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 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, @@ -2374,9 +2422,14 @@ static ssize_t ocfs2_file_read_iter(struct kiocb *iocb, * need locks to protect pending reads from racing with truncate. */ if (iocb->ki_flags & IOCB_DIRECT) { - ret = ocfs2_rw_lock(inode, 0); + 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 +2446,11 @@ 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); diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c index 098f5c7..fb9a20e 100644 --- a/fs/ocfs2/mmap.c +++ b/fs/ocfs2/mmap.c @@ -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; diff --git a/fs/ocfs2/ocfs2_trace.h b/fs/ocfs2/ocfs2_trace.h index a0b5d00..e2a11aa 100644 --- a/fs/ocfs2/ocfs2_trace.h +++ b/fs/ocfs2/ocfs2_trace.h @@ -1449,20 +1449,22 @@ 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);
Return -EAGAIN if any of the following checks fail for direct I/O with nowait flag: Can not get the related locks immediately, Blocks are not allocated at the write location, it will trigger block allocation, this will block IO operations. Signed-off-by: Gang He <ghe@suse.com> --- fs/ocfs2/dir.c | 2 +- fs/ocfs2/dlmglue.c | 20 ++++++++--- fs/ocfs2/dlmglue.h | 2 +- fs/ocfs2/file.c | 95 +++++++++++++++++++++++++++++++++++++++----------- fs/ocfs2/mmap.c | 2 +- fs/ocfs2/ocfs2_trace.h | 10 +++--- 6 files changed, 99 insertions(+), 32 deletions(-)