nfs: don't zero out the rest of the page if we hit the EOF on a DIO READ

[sagit-ice-cold/kernel_xiaomi_msm8998.git] / fs / nfs / direct.c

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 1ba385b..594f4e7 100644 (file)
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -46,6 +46,7 @@
 #include <linux/kref.h>
 #include <linux/slab.h>
 #include <linux/task_io_accounting_ops.h>
+#include <linux/module.h>
 
 #include <linux/nfs_fs.h>
 #include <linux/nfs_page.h>
@@ -78,6 +79,7 @@ struct nfs_direct_req {
        atomic_t                io_count;       /* i/os we're waiting for */
        spinlock_t              lock;           /* protect completion state */
        ssize_t                 count,          /* bytes actually processed */
+                               bytes_left,     /* bytes left to be sent */
                                error;          /* any reported error */
        struct completion       completion;     /* wait for i/o completion */
 
@@ -190,6 +192,12 @@ static void nfs_direct_req_release(struct nfs_direct_req *dreq)
        kref_put(&dreq->kref, nfs_direct_req_free);
 }
 
+ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq)
+{
+       return dreq->bytes_left;
+}
+EXPORT_SYMBOL_GPL(nfs_dreq_bytes_left);
+
 /*
  * Collects and returns the final error value/byte-count.
  */
@@ -258,14 +266,6 @@ static void nfs_direct_read_completion(struct nfs_pgio_header *hdr)
                struct nfs_page *req = nfs_list_entry(hdr->pages.next);
                struct page *page = req->wb_page;
 
-               if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) {
-                       if (bytes > hdr->good_bytes)
-                               zero_user(page, 0, PAGE_SIZE);
-                       else if (hdr->good_bytes - bytes < PAGE_SIZE)
-                               zero_user_segment(page,
-                                       hdr->good_bytes & ~PAGE_MASK,
-                                       PAGE_SIZE);
-               }
                if (!PageCompound(page)) {
                        if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) {
                                if (bytes < hdr->good_bytes)
@@ -390,6 +390,7 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
                        user_addr += req_len;
                        pos += req_len;
                        count -= req_len;
+                       dreq->bytes_left -= req_len;
                }
                /* The nfs_page now hold references to these pages */
                nfs_direct_release_pages(pagevec, npages);
@@ -450,23 +451,28 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov,
        ssize_t result = -ENOMEM;
        struct inode *inode = iocb->ki_filp->f_mapping->host;
        struct nfs_direct_req *dreq;
+       struct nfs_lock_context *l_ctx;
 
        dreq = nfs_direct_req_alloc();
        if (dreq == NULL)
                goto out;
 
        dreq->inode = inode;
+       dreq->bytes_left = iov_length(iov, nr_segs);
        dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
-       dreq->l_ctx = nfs_get_lock_context(dreq->ctx);
-       if (dreq->l_ctx == NULL)
+       l_ctx = nfs_get_lock_context(dreq->ctx);
+       if (IS_ERR(l_ctx)) {
+               result = PTR_ERR(l_ctx);
                goto out_release;
+       }
+       dreq->l_ctx = l_ctx;
        if (!is_sync_kiocb(iocb))
                dreq->iocb = iocb;
 
+       NFS_I(inode)->read_io += iov_length(iov, nr_segs);
        result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos, uio);
        if (!result)
                result = nfs_direct_wait(dreq);
-       NFS_I(inode)->read_io += result;
 out_release:
        nfs_direct_req_release(dreq);
 out:
@@ -706,6 +712,7 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *d
                        user_addr += req_len;
                        pos += req_len;
                        count -= req_len;
+                       dreq->bytes_left -= req_len;
                }
                /* The nfs_page now hold references to these pages */
                nfs_direct_release_pages(pagevec, npages);
@@ -814,6 +821,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
        get_dreq(dreq);
        atomic_inc(&inode->i_dio_count);
 
+       NFS_I(dreq->inode)->write_io += iov_length(iov, nr_segs);
        for (seg = 0; seg < nr_segs; seg++) {
                const struct iovec *vec = &iov[seg];
                result = nfs_direct_write_schedule_segment(&desc, vec, pos, uio);
@@ -825,7 +833,6 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
                pos += vec->iov_len;
        }
        nfs_pageio_complete(&desc);
-       NFS_I(dreq->inode)->write_io += desc.pg_bytes_written;
 
        /*
         * If no bytes were started, return the error, and let the
@@ -849,16 +856,21 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov,
        ssize_t result = -ENOMEM;
        struct inode *inode = iocb->ki_filp->f_mapping->host;
        struct nfs_direct_req *dreq;
+       struct nfs_lock_context *l_ctx;
 
        dreq = nfs_direct_req_alloc();
        if (!dreq)
                goto out;
 
        dreq->inode = inode;
+       dreq->bytes_left = count;
        dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
-       dreq->l_ctx = nfs_get_lock_context(dreq->ctx);
-       if (dreq->l_ctx == NULL)
+       l_ctx = nfs_get_lock_context(dreq->ctx);
+       if (IS_ERR(l_ctx)) {
+               result = PTR_ERR(l_ctx);
                goto out_release;
+       }
+       dreq->l_ctx = l_ctx;
        if (!is_sync_kiocb(iocb))
                dreq->iocb = iocb;