drop unused dentry argument to ->fsync
[safe/jmp/linux-2.6] / fs / btrfs / file.c
index ee3323c..787b50a 100644 (file)
@@ -28,6 +28,7 @@
 #include <linux/writeback.h>
 #include <linux/statfs.h>
 #include <linux/compat.h>
+#include <linux/slab.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
 static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
                                         int write_bytes,
                                         struct page **prepared_pages,
-                                        const char __user *buf)
+                                        struct iov_iter *i)
 {
-       long page_fault = 0;
-       int i;
+       size_t copied;
+       int pg = 0;
        int offset = pos & (PAGE_CACHE_SIZE - 1);
 
-       for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) {
+       while (write_bytes > 0) {
                size_t count = min_t(size_t,
                                     PAGE_CACHE_SIZE - offset, write_bytes);
-               struct page *page = prepared_pages[i];
-               fault_in_pages_readable(buf, count);
+               struct page *page = prepared_pages[pg];
+again:
+               if (unlikely(iov_iter_fault_in_readable(i, count)))
+                       return -EFAULT;
 
                /* Copy data from userspace to the current page */
-               kmap(page);
-               page_fault = __copy_from_user(page_address(page) + offset,
-                                             buf, count);
+               copied = iov_iter_copy_from_user(page, i, offset, count);
+
                /* Flush processor's dcache for this page */
                flush_dcache_page(page);
-               kunmap(page);
-               buf += count;
-               write_bytes -= count;
+               iov_iter_advance(i, copied);
+               write_bytes -= copied;
 
-               if (page_fault)
-                       break;
+               if (unlikely(copied == 0)) {
+                       count = min_t(size_t, PAGE_CACHE_SIZE - offset,
+                                     iov_iter_single_seg_count(i));
+                       goto again;
+               }
+
+               if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
+                       offset += copied;
+               } else {
+                       pg++;
+                       offset = 0;
+               }
        }
-       return page_fault ? -EFAULT : 0;
+       return 0;
 }
 
 /*
@@ -125,8 +136,7 @@ static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans,
        end_of_last_block = start_pos + num_bytes - 1;
        err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
                                        NULL);
-       if (err)
-               return err;
+       BUG_ON(err);
 
        for (i = 0; i < num_pages; i++) {
                struct page *p = pages[i];
@@ -141,7 +151,7 @@ static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans,
                 * at this time.
                 */
        }
-       return err;
+       return 0;
 }
 
 /*
@@ -822,45 +832,46 @@ again:
        return 0;
 }
 
-static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
-                               size_t count, loff_t *ppos)
+static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
+                                   const struct iovec *iov,
+                                   unsigned long nr_segs, loff_t pos)
 {
-       loff_t pos;
+       struct file *file = iocb->ki_filp;
+       struct inode *inode = fdentry(file)->d_inode;
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       struct page *pinned[2];
+       struct page **pages = NULL;
+       struct iov_iter i;
+       loff_t *ppos = &iocb->ki_pos;
        loff_t start_pos;
        ssize_t num_written = 0;
        ssize_t err = 0;
+       size_t count;
+       size_t ocount;
        int ret = 0;
-       struct inode *inode = fdentry(file)->d_inode;
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       struct page **pages = NULL;
        int nrptrs;
-       struct page *pinned[2];
        unsigned long first_index;
        unsigned long last_index;
        int will_write;
+       int buffered = 0;
 
        will_write = ((file->f_flags & O_DSYNC) || IS_SYNC(inode) ||
                      (file->f_flags & O_DIRECT));
 
-       nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE,
-                    PAGE_CACHE_SIZE / (sizeof(struct page *)));
        pinned[0] = NULL;
        pinned[1] = NULL;
 
-       pos = *ppos;
        start_pos = pos;
 
        vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
 
-       /* do the reserve before the mutex lock in case we have to do some
-        * flushing.  We wouldn't deadlock, but this is more polite.
-        */
-       err = btrfs_reserve_metadata_for_delalloc(root, inode, 1);
-       if (err)
-               goto out_nolock;
-
        mutex_lock(&inode->i_mutex);
 
+       err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
+       if (err)
+               goto out;
+       count = ocount;
+
        current->backing_dev_info = inode->i_mapping->backing_dev_info;
        err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
        if (err)
@@ -874,15 +885,53 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                goto out;
 
        file_update_time(file);
+       BTRFS_I(inode)->sequence++;
+
+       if (unlikely(file->f_flags & O_DIRECT)) {
+               num_written = generic_file_direct_write(iocb, iov, &nr_segs,
+                                                       pos, ppos, count,
+                                                       ocount);
+               /*
+                * the generic O_DIRECT will update in-memory i_size after the
+                * DIOs are done.  But our endio handlers that update the on
+                * disk i_size never update past the in memory i_size.  So we
+                * need one more update here to catch any additions to the
+                * file
+                */
+               if (inode->i_size != BTRFS_I(inode)->disk_i_size) {
+                       btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
+                       mark_inode_dirty(inode);
+               }
 
+               if (num_written < 0) {
+                       ret = num_written;
+                       num_written = 0;
+                       goto out;
+               } else if (num_written == count) {
+                       /* pick up pos changes done by the generic code */
+                       pos = *ppos;
+                       goto out;
+               }
+               /*
+                * We are going to do buffered for the rest of the range, so we
+                * need to make sure to invalidate the buffered pages when we're
+                * done.
+                */
+               buffered = 1;
+               pos += num_written;
+       }
+
+       iov_iter_init(&i, iov, nr_segs, count, num_written);
+       nrptrs = min((iov_iter_count(&i) + PAGE_CACHE_SIZE - 1) /
+                    PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
+                    (sizeof(struct page *)));
        pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
 
        /* generic_write_checks can change our pos */
        start_pos = pos;
 
-       BTRFS_I(inode)->sequence++;
        first_index = pos >> PAGE_CACHE_SHIFT;
-       last_index = (pos + count) >> PAGE_CACHE_SHIFT;
+       last_index = (pos + iov_iter_count(&i)) >> PAGE_CACHE_SHIFT;
 
        /*
         * there are lots of better ways to do this, but this code
@@ -899,7 +948,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                        unlock_page(pinned[0]);
                }
        }
-       if ((pos + count) & (PAGE_CACHE_SIZE - 1)) {
+       if ((pos + iov_iter_count(&i)) & (PAGE_CACHE_SIZE - 1)) {
                pinned[1] = grab_cache_page(inode->i_mapping, last_index);
                if (!PageUptodate(pinned[1])) {
                        ret = btrfs_readpage(NULL, pinned[1]);
@@ -910,10 +959,10 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                }
        }
 
-       while (count > 0) {
+       while (iov_iter_count(&i) > 0) {
                size_t offset = pos & (PAGE_CACHE_SIZE - 1);
-               size_t write_bytes = min(count, nrptrs *
-                                       (size_t)PAGE_CACHE_SIZE -
+               size_t write_bytes = min(iov_iter_count(&i),
+                                        nrptrs * (size_t)PAGE_CACHE_SIZE -
                                         offset);
                size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
                                        PAGE_CACHE_SHIFT;
@@ -921,7 +970,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                WARN_ON(num_pages > nrptrs);
                memset(pages, 0, sizeof(struct page *) * nrptrs);
 
-               ret = btrfs_check_data_free_space(root, inode, write_bytes);
+               ret = btrfs_delalloc_reserve_space(inode, write_bytes);
                if (ret)
                        goto out;
 
@@ -929,26 +978,20 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                                    pos, first_index, last_index,
                                    write_bytes);
                if (ret) {
-                       btrfs_free_reserved_data_space(root, inode,
-                                                      write_bytes);
+                       btrfs_delalloc_release_space(inode, write_bytes);
                        goto out;
                }
 
                ret = btrfs_copy_from_user(pos, num_pages,
-                                          write_bytes, pages, buf);
-               if (ret) {
-                       btrfs_free_reserved_data_space(root, inode,
-                                                      write_bytes);
-                       btrfs_drop_pages(pages, num_pages);
-                       goto out;
+                                          write_bytes, pages, &i);
+               if (ret == 0) {
+                       dirty_and_release_pages(NULL, root, file, pages,
+                                               num_pages, pos, write_bytes);
                }
 
-               ret = dirty_and_release_pages(NULL, root, file, pages,
-                                             num_pages, pos, write_bytes);
                btrfs_drop_pages(pages, num_pages);
                if (ret) {
-                       btrfs_free_reserved_data_space(root, inode,
-                                                      write_bytes);
+                       btrfs_delalloc_release_space(inode, write_bytes);
                        goto out;
                }
 
@@ -964,8 +1007,6 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                        btrfs_throttle(root);
                }
 
-               buf += write_bytes;
-               count -= write_bytes;
                pos += write_bytes;
                num_written += write_bytes;
 
@@ -975,9 +1016,7 @@ out:
        mutex_unlock(&inode->i_mutex);
        if (ret)
                err = ret;
-       btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
 
-out_nolock:
        kfree(pages);
        if (pinned[0])
                page_cache_release(pinned[0]);
@@ -1007,7 +1046,7 @@ out_nolock:
                        num_written = err;
 
                if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) {
-                       trans = btrfs_start_transaction(root, 1);
+                       trans = btrfs_start_transaction(root, 0);
                        ret = btrfs_log_dentry_safe(trans, root,
                                                    file->f_dentry);
                        if (ret == 0) {
@@ -1022,7 +1061,7 @@ out_nolock:
                                btrfs_end_transaction(trans, root);
                        }
                }
-               if (file->f_flags & O_DIRECT) {
+               if (file->f_flags & O_DIRECT && buffered) {
                        invalidate_mapping_pages(inode->i_mapping,
                              start_pos >> PAGE_CACHE_SHIFT,
                             (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT);
@@ -1062,8 +1101,9 @@ int btrfs_release_file(struct inode *inode, struct file *filp)
  * important optimization for directories because holding the mutex prevents
  * new operations on the dir while we write to disk.
  */
-int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
+int btrfs_sync_file(struct file *file, int datasync)
 {
+       struct dentry *dentry = file->f_path.dentry;
        struct inode *inode = dentry->d_inode;
        struct btrfs_root *root = BTRFS_I(inode)->root;
        int ret = 0;
@@ -1103,9 +1143,9 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
        if (file && file->private_data)
                btrfs_ioctl_trans_end(file);
 
-       trans = btrfs_start_transaction(root, 1);
-       if (!trans) {
-               ret = -ENOMEM;
+       trans = btrfs_start_transaction(root, 0);
+       if (IS_ERR(trans)) {
+               ret = PTR_ERR(trans);
                goto out;
        }
 
@@ -1160,7 +1200,7 @@ const struct file_operations btrfs_file_operations = {
        .read           = do_sync_read,
        .aio_read       = generic_file_aio_read,
        .splice_read    = generic_file_splice_read,
-       .write          = btrfs_file_write,
+       .aio_write      = btrfs_file_aio_write,
        .mmap           = btrfs_file_mmap,
        .open           = generic_file_open,
        .release        = btrfs_release_file,