ocfs2: Add splice support

Add splice read/write support in ocfs2.

ocfs2_file_splice_read/write are very similar to ocfs2_file_aio_read/write.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 137 insertions, 50 deletions

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 39b2f1653e25..b32cdb3bf7c5 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -31,6 +31,7 @@
 #include <linux/pagemap.h>
 #include <linux/uio.h>
 #include <linux/sched.h>
+#include <linux/pipe_fs_i.h>
 
 #define MLOG_MASK_PREFIX ML_INODE
 #include <cluster/masklog.h>
@@ -943,53 +944,21 @@ out:
         return ret;
 }
 
-static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
-                                    const struct iovec *iov,
-                                    unsigned long nr_segs,
-                                    loff_t pos)
+static int ocfs2_prepare_inode_for_write(struct dentry *dentry,
+                                         loff_t *ppos,
+                                         size_t count,
+                                         int appending)
 {
-        int ret, rw_level = -1, meta_level = -1, have_alloc_sem = 0;
+        int ret = 0, meta_level = appending;
+        struct inode *inode = dentry->d_inode;
         u32 clusters;
-        struct file *filp = iocb->ki_filp;
-        struct inode *inode = filp->f_dentry->d_inode;
         loff_t newsize, saved_pos;
 
-        mlog_entry("(0x%p, %u, '%.*s')\n", filp,
-                   (unsigned int)nr_segs,
-                   filp->f_dentry->d_name.len,
-                   filp->f_dentry->d_name.name);
-
-        /* happy write of zero bytes */
-        if (iocb->ki_left == 0)
-                return 0;
-
-        if (!inode) {
-                mlog(0, "bad inode\n");
-                return -EIO;
-        }
-
-        mutex_lock(&inode->i_mutex);
-        /* to match setattr's i_mutex -> i_alloc_sem -> rw_lock ordering */
-        if (filp->f_flags & O_DIRECT) {
-                have_alloc_sem = 1;
-                down_read(&inode->i_alloc_sem);
-        }
-
-        /* concurrent O_DIRECT writes are allowed */
-        rw_level = (filp->f_flags & O_DIRECT) ? 0 : 1;
-        ret = ocfs2_rw_lock(inode, rw_level);
-        if (ret < 0) {
-                rw_level = -1;
-                mlog_errno(ret);
-                goto out;
-        }
-
         /* 
          * We sample i_size under a read level meta lock to see if our write
          * is extending the file, if it is we back off and get a write level
          * meta lock.
          */
-        meta_level = (filp->f_flags & O_APPEND) ? 1 : 0;
         for(;;) {
                 ret = ocfs2_meta_lock(inode, NULL, meta_level);
                 if (ret < 0) {
@@ -1007,7 +976,7 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
                  * inode. There's also the dinode i_size state which
                  * can be lost via setattr during extending writes (we
                  * set inode->i_size at the end of a write. */
-                if (should_remove_suid(filp->f_dentry)) {
+                if (should_remove_suid(dentry)) {
                         if (meta_level == 0) {
                                 ocfs2_meta_unlock(inode, meta_level);
                                 meta_level = 1;
@@ -1017,19 +986,19 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
                         ret = ocfs2_write_remove_suid(inode);
                         if (ret < 0) {
                                 mlog_errno(ret);
-                                goto out;
+                                goto out_unlock;
                         }
                 }
 
                 /* work on a copy of ppos until we're sure that we won't have
                  * to recalculate it due to relocking. */
-                if (filp->f_flags & O_APPEND) {
+                if (appending) {
                         saved_pos = i_size_read(inode);
                         mlog(0, "O_APPEND: inode->i_size=%llu\n", saved_pos);
                 } else {
-                        saved_pos = iocb->ki_pos;
+                        saved_pos = *ppos;
                 }
-                newsize = iocb->ki_left + saved_pos;
+                newsize = count + saved_pos;
 
                 mlog(0, "pos=%lld newsize=%lld cursize=%lld\n",
                      (long long) saved_pos, (long long) newsize,
@@ -1062,19 +1031,66 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
                 if (!clusters)
                         break;
 
-                ret = ocfs2_extend_file(inode, NULL, newsize, iocb->ki_left);
+                ret = ocfs2_extend_file(inode, NULL, newsize, count);
                 if (ret < 0) {
                         if (ret != -ENOSPC)
                                 mlog_errno(ret);
-                        goto out;
+                        goto out_unlock;
                 }
                 break;
         }
 
-        /* ok, we're done with i_size and alloc work */
-        iocb->ki_pos = saved_pos;
+        if (appending)
+                *ppos = saved_pos;
+
+out_unlock:
         ocfs2_meta_unlock(inode, meta_level);
-        meta_level = -1;
+
+out:
+        return ret;
+}
+
+static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
+                                    const struct iovec *iov,
+                                    unsigned long nr_segs,
+                                    loff_t pos)
+{
+        int ret, rw_level, have_alloc_sem = 0;
+        struct file *filp = iocb->ki_filp;
+        struct inode *inode = filp->f_dentry->d_inode;
+        int appending = filp->f_flags & O_APPEND ? 1 : 0;
+
+        mlog_entry("(0x%p, %u, '%.*s')\n", filp,
+                   (unsigned int)nr_segs,
+                   filp->f_dentry->d_name.len,
+                   filp->f_dentry->d_name.name);
+
+        /* happy write of zero bytes */
+        if (iocb->ki_left == 0)
+                return 0;
+
+        mutex_lock(&inode->i_mutex);
+        /* to match setattr's i_mutex -> i_alloc_sem -> rw_lock ordering */
+        if (filp->f_flags & O_DIRECT) {
+                have_alloc_sem = 1;
+                down_read(&inode->i_alloc_sem);
+        }
+
+        /* concurrent O_DIRECT writes are allowed */
+        rw_level = (filp->f_flags & O_DIRECT) ? 0 : 1;
+        ret = ocfs2_rw_lock(inode, rw_level);
+        if (ret < 0) {
+                rw_level = -1;
+                mlog_errno(ret);
+                goto out;
+        }
+
+        ret = ocfs2_prepare_inode_for_write(filp->f_dentry, &iocb->ki_pos,
+                                            iocb->ki_left, appending);
+        if (ret < 0) {
+                mlog_errno(ret);
+                goto out;
+        }
 
         /* communicate with ocfs2_dio_end_io */
         ocfs2_iocb_set_rw_locked(iocb);
@@ -1100,8 +1116,6 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
         }
 
 out:
-        if (meta_level != -1)
-                ocfs2_meta_unlock(inode, meta_level);
         if (have_alloc_sem)
                 up_read(&inode->i_alloc_sem);
         if (rw_level != -1) 
@@ -1112,6 +1126,77 @@ out:
         return ret;
 }
 
+static ssize_t ocfs2_file_splice_write(struct pipe_inode_info *pipe,
+                                       struct file *out,
+                                       loff_t *ppos,
+                                       size_t len,
+                                       unsigned int flags)
+{
+        int ret;
+        struct inode *inode = out->f_dentry->d_inode;
+
+        mlog_entry("(0x%p, 0x%p, %u, '%.*s')\n", out, pipe,
+                   (unsigned int)len,
+                   out->f_dentry->d_name.len,
+                   out->f_dentry->d_name.name);
+
+        inode_double_lock(inode, pipe->inode);
+
+        ret = ocfs2_rw_lock(inode, 1);
+        if (ret < 0) {
+                mlog_errno(ret);
+                goto out;
+        }
+
+        ret = ocfs2_prepare_inode_for_write(out->f_dentry, ppos, len, 0);
+        if (ret < 0) {
+                mlog_errno(ret);
+                goto out_unlock;
+        }
+
+        /* ok, we're done with i_size and alloc work */
+        ret = generic_file_splice_write_nolock(pipe, out, ppos, len, flags);
+
+out_unlock:
+        ocfs2_rw_unlock(inode, 1);
+out:
+        inode_double_unlock(inode, pipe->inode);
+
+        mlog_exit(ret);
+        return ret;
+}
+
+static ssize_t ocfs2_file_splice_read(struct file *in,
+                                      loff_t *ppos,
+                                      struct pipe_inode_info *pipe,
+                                      size_t len,
+                                      unsigned int flags)
+{
+        int ret = 0;
+        struct inode *inode = in->f_dentry->d_inode;
+
+        mlog_entry("(0x%p, 0x%p, %u, '%.*s')\n", in, pipe,
+                   (unsigned int)len,
+                   in->f_dentry->d_name.len,
+                   in->f_dentry->d_name.name);
+
+        /*
+         * See the comment in ocfs2_file_aio_read()
+         */
+        ret = ocfs2_meta_lock(inode, NULL, 0);
+        if (ret < 0) {
+                mlog_errno(ret);
+                goto bail;
+        }
+        ocfs2_meta_unlock(inode, 0);
+
+        ret = generic_file_splice_read(in, ppos, pipe, len, flags);
+
+bail:
+        mlog_exit(ret);
+        return ret;
+}
+
 static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
                                    const struct iovec *iov,
                                    unsigned long nr_segs,
@@ -1210,6 +1295,8 @@ const struct file_operations ocfs2_fops = {
         .aio_read       = ocfs2_file_aio_read,
         .aio_write      = ocfs2_file_aio_write,
         .ioctl          = ocfs2_ioctl,
+        .splice_read    = ocfs2_file_splice_read,
+        .splice_write   = ocfs2_file_splice_write,
 };
 
 const struct file_operations ocfs2_dops = {