5 files changed, 135 insertions, 62 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 6f820fa23df4..7f78cc78fdd0 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -729,6 +729,15 @@ struct btrfs_space_info {
         u64 disk_total;         /* total bytes on disk, takes mirrors into
                                    account */
 
+        /*
+         * we bump reservation progress every time we decrement
+         * bytes_reserved.  This way people waiting for reservations
+         * know something good has happened and they can check
+         * for progress.  The number here isn't to be trusted, it
+         * just shows reclaim activity
+         */
+        unsigned long reservation_progress;
+
         int full;               /* indicates that we cannot allocate any more
                                    chunks for this space */
         int force_alloc;        /* set if we need to force a chunk alloc for
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 588ff9849873..7b3089b5c2df 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3342,15 +3342,16 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
         u64 max_reclaim;
         u64 reclaimed = 0;
         long time_left;
-        int pause = 1;
         int nr_pages = (2 * 1024 * 1024) >> PAGE_CACHE_SHIFT;
         int loops = 0;
+        unsigned long progress;
 
         block_rsv = &root->fs_info->delalloc_block_rsv;
         space_info = block_rsv->space_info;
 
         smp_mb();
         reserved = space_info->bytes_reserved;
+        progress = space_info->reservation_progress;
 
         if (reserved == 0)
                 return 0;
@@ -3365,31 +3366,36 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
                 writeback_inodes_sb_nr_if_idle(root->fs_info->sb, nr_pages);
 
                 spin_lock(&space_info->lock);
-                if (reserved > space_info->bytes_reserved) {
-                        loops = 0;
+                if (reserved > space_info->bytes_reserved)
                         reclaimed += reserved - space_info->bytes_reserved;
-                } else {
-                        loops++;
-                }
                 reserved = space_info->bytes_reserved;
                 spin_unlock(&space_info->lock);
 
+                loops++;
+
                 if (reserved == 0 || reclaimed >= max_reclaim)
                         break;
 
                 if (trans && trans->transaction->blocked)
                         return -EAGAIN;
 
-                __set_current_state(TASK_INTERRUPTIBLE);
-                time_left = schedule_timeout(pause);
+                time_left = schedule_timeout_interruptible(1);
 
                 /* We were interrupted, exit */
                 if (time_left)
                         break;
 
-                pause <<= 1;
-                if (pause > HZ / 10)
-                        pause = HZ / 10;
+                /* we've kicked the IO a few times, if anything has been freed,
+                 * exit.  There is no sense in looping here for a long time
+                 * when we really need to commit the transaction, or there are
+                 * just too many writers without enough free space
+                 */
+
+                if (loops > 3) {
+                        smp_mb();
+                        if (progress != space_info->reservation_progress)
+                                break;
+                }
 
         }
         return reclaimed >= to_reclaim;
@@ -3612,6 +3618,7 @@ void block_rsv_release_bytes(struct btrfs_block_rsv *block_rsv,
                 if (num_bytes) {
                         spin_lock(&space_info->lock);
                         space_info->bytes_reserved -= num_bytes;
+                        space_info->reservation_progress++;
                         spin_unlock(&space_info->lock);
                 }
         }
@@ -3844,6 +3851,7 @@ static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
         if (block_rsv->reserved >= block_rsv->size) {
                 num_bytes = block_rsv->reserved - block_rsv->size;
                 sinfo->bytes_reserved -= num_bytes;
+                sinfo->reservation_progress++;
                 block_rsv->reserved = block_rsv->size;
                 block_rsv->full = 1;
         }
@@ -4005,7 +4013,6 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
                 to_reserve = 0;
         }
         spin_unlock(&BTRFS_I(inode)->accounting_lock);
-
         to_reserve += calc_csum_metadata_size(inode, num_bytes);
         ret = reserve_metadata_bytes(NULL, root, block_rsv, to_reserve, 1);
         if (ret)
@@ -4133,6 +4140,7 @@ static int update_block_group(struct btrfs_trans_handle *trans,
                         btrfs_set_block_group_used(&cache->item, old_val);
                         cache->reserved -= num_bytes;
                         cache->space_info->bytes_reserved -= num_bytes;
+                        cache->space_info->reservation_progress++;
                         cache->space_info->bytes_used += num_bytes;
                         cache->space_info->disk_used += num_bytes * factor;
                         spin_unlock(&cache->lock);
@@ -4184,6 +4192,7 @@ static int pin_down_extent(struct btrfs_root *root,
         if (reserved) {
                 cache->reserved -= num_bytes;
                 cache->space_info->bytes_reserved -= num_bytes;
+                cache->space_info->reservation_progress++;
         }
         spin_unlock(&cache->lock);
         spin_unlock(&cache->space_info->lock);
@@ -4234,6 +4243,7 @@ static int update_reserved_bytes(struct btrfs_block_group_cache *cache,
                                 space_info->bytes_readonly += num_bytes;
                         cache->reserved -= num_bytes;
                         space_info->bytes_reserved -= num_bytes;
+                        space_info->reservation_progress++;
                 }
                 spin_unlock(&cache->lock);
                 spin_unlock(&space_info->lock);
@@ -4712,6 +4722,7 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
                 if (ret) {
                         spin_lock(&cache->space_info->lock);
                         cache->space_info->bytes_reserved -= buf->len;
+                        cache->space_info->reservation_progress++;
                         spin_unlock(&cache->space_info->lock);
                 }
                 goto out;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index fd3f172e94e6..714adc4ac4c2 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3046,17 +3046,38 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
         }
 
         while (!end) {
-                off = extent_map_end(em);
-                if (off >= max)
-                        end = 1;
+                u64 offset_in_extent;
+
+                /* break if the extent we found is outside the range */
+                if (em->start >= max || extent_map_end(em) < off)
+                        break;
+
+                /*
+                 * get_extent may return an extent that starts before our
+                 * requested range.  We have to make sure the ranges
+                 * we return to fiemap always move forward and don't
+                 * overlap, so adjust the offsets here
+                 */
+                em_start = max(em->start, off);
 
-                em_start = em->start;
-                em_len = em->len;
+                /*
+                 * record the offset from the start of the extent
+                 * for adjusting the disk offset below
+                 */
+                offset_in_extent = em_start - em->start;
                 em_end = extent_map_end(em);
+                em_len = em_end - em_start;
                 emflags = em->flags;
                 disko = 0;
                 flags = 0;
 
+                /*
+                 * bump off for our next call to get_extent
+                 */
+                off = extent_map_end(em);
+                if (off >= max)
+                        end = 1;
+
                 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
                         end = 1;
                         flags |= FIEMAP_EXTENT_LAST;
@@ -3067,7 +3088,7 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                         flags |= (FIEMAP_EXTENT_DELALLOC |
                                   FIEMAP_EXTENT_UNKNOWN);
                 } else {
-                        disko = em->block_start;
+                        disko = em->block_start + offset_in_extent;
                 }
                 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
                         flags |= FIEMAP_EXTENT_ENCODED;
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 7084140d5940..f447b783bb84 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -70,6 +70,19 @@ static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
 
                 /* Flush processor's dcache for this page */
                 flush_dcache_page(page);
+
+                /*
+                 * if we get a partial write, we can end up with
+                 * partially up to date pages.  These add
+                 * a lot of complexity, so make sure they don't
+                 * happen by forcing this copy to be retried.
+                 *
+                 * The rest of the btrfs_file_write code will fall
+                 * back to page at a time copies after we return 0.
+                 */
+                if (!PageUptodate(page) && copied < count)
+                        copied = 0;
+
                 iov_iter_advance(i, copied);
                 write_bytes -= copied;
                 total_copied += copied;
@@ -763,6 +776,27 @@ out:
 }
 
 /*
+ * on error we return an unlocked page and the error value
+ * on success we return a locked page and 0
+ */
+static int prepare_uptodate_page(struct page *page, u64 pos)
+{
+        int ret = 0;
+
+        if ((pos & (PAGE_CACHE_SIZE - 1)) && !PageUptodate(page)) {
+                ret = btrfs_readpage(NULL, page);
+                if (ret)
+                        return ret;
+                lock_page(page);
+                if (!PageUptodate(page)) {
+                        unlock_page(page);
+                        return -EIO;
+                }
+        }
+        return 0;
+}
+
+/*
  * this gets pages into the page cache and locks them down, it also properly
  * waits for data=ordered extents to finish before allowing the pages to be
  * modified.
@@ -777,6 +811,7 @@ static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
         unsigned long index = pos >> PAGE_CACHE_SHIFT;
         struct inode *inode = fdentry(file)->d_inode;
         int err = 0;
+        int faili = 0;
         u64 start_pos;
         u64 last_pos;
 
@@ -794,15 +829,24 @@ again:
         for (i = 0; i < num_pages; i++) {
                 pages[i] = grab_cache_page(inode->i_mapping, index + i);
                 if (!pages[i]) {
-                        int c;
-                        for (c = i - 1; c >= 0; c--) {
-                                unlock_page(pages[c]);
-                                page_cache_release(pages[c]);
-                        }
-                        return -ENOMEM;
+                        faili = i - 1;
+                        err = -ENOMEM;
+                        goto fail;
+                }
+
+                if (i == 0)
+                        err = prepare_uptodate_page(pages[i], pos);
+                if (i == num_pages - 1)
+                        err = prepare_uptodate_page(pages[i],
+                                                    pos + write_bytes);
+                if (err) {
+                        page_cache_release(pages[i]);
+                        faili = i - 1;
+                        goto fail;
                 }
                 wait_on_page_writeback(pages[i]);
         }
+        err = 0;
         if (start_pos < inode->i_size) {
                 struct btrfs_ordered_extent *ordered;
                 lock_extent_bits(&BTRFS_I(inode)->io_tree,
@@ -842,6 +886,14 @@ again:
                 WARN_ON(!PageLocked(pages[i]));
         }
         return 0;
+fail:
+        while (faili >= 0) {
+                unlock_page(pages[faili]);
+                page_cache_release(pages[faili]);
+                faili--;
+        }
+        return err;
+
 }
 
 static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
@@ -851,7 +903,6 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
         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;
@@ -872,9 +923,6 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
         will_write = ((file->f_flags & O_DSYNC) || IS_SYNC(inode) ||
                       (file->f_flags & O_DIRECT));
 
-        pinned[0] = NULL;
-        pinned[1] = NULL;
-
         start_pos = pos;
 
         vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
@@ -962,32 +1010,6 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
         first_index = pos >> 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
-         * makes sure the first and last page in the file range are
-         * up to date and ready for cow
-         */
-        if ((pos & (PAGE_CACHE_SIZE - 1))) {
-                pinned[0] = grab_cache_page(inode->i_mapping, first_index);
-                if (!PageUptodate(pinned[0])) {
-                        ret = btrfs_readpage(NULL, pinned[0]);
-                        BUG_ON(ret);
-                        wait_on_page_locked(pinned[0]);
-                } else {
-                        unlock_page(pinned[0]);
-                }
-        }
-        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]);
-                        BUG_ON(ret);
-                        wait_on_page_locked(pinned[1]);
-                } else {
-                        unlock_page(pinned[1]);
-                }
-        }
-
         while (iov_iter_count(&i) > 0) {
                 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
                 size_t write_bytes = min(iov_iter_count(&i),
@@ -1024,8 +1046,20 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
 
                 copied = btrfs_copy_from_user(pos, num_pages,
                                            write_bytes, pages, &i);
-                dirty_pages = (copied + offset + PAGE_CACHE_SIZE - 1) >>
-                                PAGE_CACHE_SHIFT;
+
+                /*
+                 * if we have trouble faulting in the pages, fall
+                 * back to one page at a time
+                 */
+                if (copied < write_bytes)
+                        nrptrs = 1;
+
+                if (copied == 0)
+                        dirty_pages = 0;
+                else
+                        dirty_pages = (copied + offset +
+                                       PAGE_CACHE_SIZE - 1) >>
+                                       PAGE_CACHE_SHIFT;
 
                 if (num_pages > dirty_pages) {
                         if (copied > 0)
@@ -1069,10 +1103,6 @@ out:
                 err = ret;
 
         kfree(pages);
-        if (pinned[0])
-                page_cache_release(pinned[0]);
-        if (pinned[1])
-                page_cache_release(pinned[1]);
         *ppos = pos;
 
         /*
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 0efdb65953c5..9007bbd01dbf 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4821,10 +4821,11 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
                 goto fail;
 
         /*
-         * 1 item for inode ref
+         * 2 items for inode and inode ref
          * 2 items for dir items
+         * 1 item for parent inode
          */
-        trans = btrfs_start_transaction(root, 3);
+        trans = btrfs_start_transaction(root, 5);
         if (IS_ERR(trans)) {
                 err = PTR_ERR(trans);
                 goto fail;
@@ -6056,6 +6057,7 @@ static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
         if (!skip_sum) {
                 dip->csums = kmalloc(sizeof(u32) * bio->bi_vcnt, GFP_NOFS);
                 if (!dip->csums) {
+                        kfree(dip);
                         ret = -ENOMEM;
                         goto free_ordered;
                 }