ceph: switch to ->write_iter()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 26 insertions, 31 deletions

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index f68964076c0a..0a1541416fc2 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -531,8 +531,7 @@ static void ceph_sync_write_unsafe(struct ceph_osd_request *req, bool unsafe)
  * objects, rollback on failure, etc.)
  */
 static ssize_t
-ceph_sync_direct_write(struct kiocb *iocb, const struct iovec *iov,
-                       unsigned long nr_segs, size_t count)
+ceph_sync_direct_write(struct kiocb *iocb, struct iov_iter *from)
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file_inode(file);
@@ -549,7 +548,7 @@ ceph_sync_direct_write(struct kiocb *iocb, const struct iovec *iov,
         int ret;
         struct timespec mtime = CURRENT_TIME;
         loff_t pos = iocb->ki_pos;
-        struct iov_iter i;
+        size_t count = iov_iter_count(from);
 
         if (ceph_snap(file_inode(file)) != CEPH_NOSNAP)
                 return -EROFS;
@@ -571,10 +570,8 @@ ceph_sync_direct_write(struct kiocb *iocb, const struct iovec *iov,
                 CEPH_OSD_FLAG_ONDISK |
                 CEPH_OSD_FLAG_WRITE;
 
-        iov_iter_init(&i, WRITE, iov, nr_segs, count);
-
-        while (iov_iter_count(&i) > 0) {
-                u64 len = iov_iter_single_seg_count(&i);
+        while (iov_iter_count(from) > 0) {
+                u64 len = iov_iter_single_seg_count(from);
                 size_t start;
                 ssize_t n;
 
@@ -592,7 +589,7 @@ ceph_sync_direct_write(struct kiocb *iocb, const struct iovec *iov,
                         break;
                 }
 
-                n = iov_iter_get_pages_alloc(&i, &pages, len, &start);
+                n = iov_iter_get_pages_alloc(from, &pages, len, &start);
                 if (unlikely(n < 0)) {
                         ret = n;
                         ceph_osdc_put_request(req);
@@ -623,7 +620,7 @@ ceph_sync_direct_write(struct kiocb *iocb, const struct iovec *iov,
                         break;
                 pos += n;
                 written += n;
-                iov_iter_advance(&i, n);
+                iov_iter_advance(from, n);
 
                 if (pos > i_size_read(inode)) {
                         check_caps = ceph_inode_set_size(inode, pos);
@@ -649,8 +646,7 @@ ceph_sync_direct_write(struct kiocb *iocb, const struct iovec *iov,
  * correct atomic write, we should e.g. take write locks on all
  * objects, rollback on failure, etc.)
  */
-static ssize_t ceph_sync_write(struct kiocb *iocb, const struct iovec *iov,
-                               unsigned long nr_segs, size_t count)
+static ssize_t ceph_sync_write(struct kiocb *iocb, struct iov_iter *from)
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file_inode(file);
@@ -668,7 +664,7 @@ static ssize_t ceph_sync_write(struct kiocb *iocb, const struct iovec *iov,
         int ret;
         struct timespec mtime = CURRENT_TIME;
         loff_t pos = iocb->ki_pos;
-        struct iov_iter i;
+        size_t count = iov_iter_count(from);
 
         if (ceph_snap(file_inode(file)) != CEPH_NOSNAP)
                 return -EROFS;
@@ -690,9 +686,7 @@ static ssize_t ceph_sync_write(struct kiocb *iocb, const struct iovec *iov,
                 CEPH_OSD_FLAG_WRITE |
                 CEPH_OSD_FLAG_ACK;
 
-        iov_iter_init(&i, WRITE, iov, nr_segs, count);
-
-        while ((len = iov_iter_count(&i)) > 0) {
+        while ((len = iov_iter_count(from)) > 0) {
                 size_t left;
                 int n;
 
@@ -724,7 +718,7 @@ static ssize_t ceph_sync_write(struct kiocb *iocb, const struct iovec *iov,
                 left = len;
                 for (n = 0; n < num_pages; n++) {
                         size_t plen = min_t(size_t, left, PAGE_SIZE);
-                        ret = copy_page_from_iter(pages[n], 0, plen, &i);
+                        ret = copy_page_from_iter(pages[n], 0, plen, from);
                         if (ret != plen) {
                                 ret = -EFAULT;
                                 break;
@@ -861,8 +855,7 @@ again:
  *
  * If we are near ENOSPC, write synchronously.
  */
-static ssize_t ceph_aio_write(struct kiocb *iocb, const struct iovec *iov,
-                       unsigned long nr_segs, loff_t pos)
+static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
         struct file *file = iocb->ki_filp;
         struct ceph_file_info *fi = file->private_data;
@@ -870,16 +863,15 @@ static ssize_t ceph_aio_write(struct kiocb *iocb, const struct iovec *iov,
         struct ceph_inode_info *ci = ceph_inode(inode);
         struct ceph_osd_client *osdc =
                 &ceph_sb_to_client(inode->i_sb)->client->osdc;
-        ssize_t count, written = 0;
+        ssize_t count = iov_iter_count(from), written = 0;
         int err, want, got;
+        loff_t pos = iocb->ki_pos;
 
         if (ceph_snap(inode) != CEPH_NOSNAP)
                 return -EROFS;
 
         mutex_lock(&inode->i_mutex);
 
-        count = iov_length(iov, nr_segs);
-
         /* We can write back this queue in page reclaim */
         current->backing_dev_info = file->f_mapping->backing_dev_info;
 
@@ -889,6 +881,7 @@ static ssize_t ceph_aio_write(struct kiocb *iocb, const struct iovec *iov,
 
         if (count == 0)
                 goto out;
+        iov_iter_truncate(from, count);
 
         err = file_remove_suid(file);
         if (err)
@@ -920,23 +913,26 @@ retry_snap:
 
         if ((got & (CEPH_CAP_FILE_BUFFER|CEPH_CAP_FILE_LAZYIO)) == 0 ||
             (file->f_flags & O_DIRECT) || (fi->flags & CEPH_F_SYNC)) {
+                struct iov_iter data;
                 mutex_unlock(&inode->i_mutex);
+                /* we might need to revert back to that point */
+                data = *from;
                 if (file->f_flags & O_DIRECT)
-                        written = ceph_sync_direct_write(iocb, iov,
-                                                         nr_segs, count);
+                        written = ceph_sync_direct_write(iocb, &data);
                 else
-                        written = ceph_sync_write(iocb, iov, nr_segs, count);
+                        written = ceph_sync_write(iocb, &data);
                 if (written == -EOLDSNAPC) {
                         dout("aio_write %p %llx.%llx %llu~%u"
                                 "got EOLDSNAPC, retrying\n",
                                 inode, ceph_vinop(inode),
-                                pos, (unsigned)iov->iov_len);
+                                pos, (unsigned)count);
                         mutex_lock(&inode->i_mutex);
                         goto retry_snap;
                 }
+                if (written > 0)
+                        iov_iter_advance(from, written);
         } else {
                 loff_t old_size = inode->i_size;
-                struct iov_iter from;
                 /*
                  * No need to acquire the i_truncate_mutex. Because
                  * the MDS revokes Fwb caps before sending truncate
@@ -944,8 +940,7 @@ retry_snap:
                  * are pending vmtruncate. So write and vmtruncate
                  * can not run at the same time
                  */
-                iov_iter_init(&from, WRITE, iov, nr_segs, count);
-                written = generic_perform_write(file, &from, pos);
+                written = generic_perform_write(file, from, pos);
                 if (likely(written >= 0))
                         iocb->ki_pos = pos + written;
                 if (inode->i_size > old_size)
@@ -963,7 +958,7 @@ retry_snap:
         }
 
         dout("aio_write %p %llx.%llx %llu~%u  dropping cap refs on %s\n",
-             inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len,
+             inode, ceph_vinop(inode), pos, (unsigned)count,
              ceph_cap_string(got));
         ceph_put_cap_refs(ci, got);
 
@@ -1241,9 +1236,9 @@ const struct file_operations ceph_file_fops = {
         .release = ceph_release,
         .llseek = ceph_llseek,
         .read = new_sync_read,
-        .write = do_sync_write,
+        .write = new_sync_write,
         .read_iter = ceph_read_iter,
-        .aio_write = ceph_aio_write,
+        .write_iter = ceph_write_iter,
         .mmap = ceph_mmap,
         .fsync = ceph_fsync,
         .lock = ceph_lock,