Revert "ext4: fix suboptimal seek_{data,hole} extents traversial"

This reverts commit 14516bb7bb6ffbd49f35389f9ece3b2045ba5815.

This was causing regression test failures with generic/285 with an ext3
filesystem using CONFIG_EXT4_USE_FOR_EXT23.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e5d3eadf47b1e7fb6251c590016044cf8b5c4c98..bed43081720f718fc30dca204be8509ddcf5eac5 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -5166,8 +5166,8 @@ int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 
        /* fallback to generic here if not in extents fmt */
        if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
-               return __generic_block_fiemap(inode, fieinfo, start, len,
-                                             ext4_get_block);
+               return generic_block_fiemap(inode, fieinfo, start, len,
+                       ext4_get_block);
 
        if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
                return -EBADR;

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 513c12cf444c239f5c34bd4d73c653029bdaca96..8131be8c0af3166aac865557baa9f0371564a397 100644 (file)
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -273,19 +273,24 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
  * we determine this extent as a data or a hole according to whether the
  * page cache has data or not.
  */
-static int ext4_find_unwritten_pgoff(struct inode *inode, int whence,
-                                    loff_t endoff, loff_t *offset)
+static int ext4_find_unwritten_pgoff(struct inode *inode,
+                                    int whence,
+                                    struct ext4_map_blocks *map,
+                                    loff_t *offset)
 {
        struct pagevec pvec;
+       unsigned int blkbits;
        pgoff_t index;
        pgoff_t end;
+       loff_t endoff;
        loff_t startoff;
        loff_t lastoff;
        int found = 0;
 
+       blkbits = inode->i_sb->s_blocksize_bits;
        startoff = *offset;
        lastoff = startoff;
-
+       endoff = (loff_t)(map->m_lblk + map->m_len) << blkbits;
 
        index = startoff >> PAGE_CACHE_SHIFT;
        end = endoff >> PAGE_CACHE_SHIFT;
@@ -403,144 +408,147 @@ out:
 static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
 {
        struct inode *inode = file->f_mapping->host;
-       struct fiemap_extent_info fie;
-       struct fiemap_extent ext[2];
-       loff_t next;
-       int i, ret = 0;
+       struct ext4_map_blocks map;
+       struct extent_status es;
+       ext4_lblk_t start, last, end;
+       loff_t dataoff, isize;
+       int blkbits;
+       int ret = 0;
 
        mutex_lock(&inode->i_mutex);
-       if (offset >= inode->i_size) {
+
+       isize = i_size_read(inode);
+       if (offset >= isize) {
                mutex_unlock(&inode->i_mutex);
                return -ENXIO;
        }
-       fie.fi_flags = 0;
-       fie.fi_extents_max = 2;
-       fie.fi_extents_start = (struct fiemap_extent __user *) &ext;
-       while (1) {
-               mm_segment_t old_fs = get_fs();
-
-               fie.fi_extents_mapped = 0;
-               memset(ext, 0, sizeof(*ext) * fie.fi_extents_max);
-
-               set_fs(get_ds());
-               ret = ext4_fiemap(inode, &fie, offset, maxsize - offset);
-               set_fs(old_fs);
-               if (ret)
+
+       blkbits = inode->i_sb->s_blocksize_bits;
+       start = offset >> blkbits;
+       last = start;
+       end = isize >> blkbits;
+       dataoff = offset;
+
+       do {
+               map.m_lblk = last;
+               map.m_len = end - last + 1;
+               ret = ext4_map_blocks(NULL, inode, &map, 0);
+               if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) {
+                       if (last != start)
+                               dataoff = (loff_t)last << blkbits;
                        break;
+               }
 
-               /* No extents found, EOF */
-               if (!fie.fi_extents_mapped) {
-                       ret = -ENXIO;
+               /*
+                * If there is a delay extent at this offset,
+                * it will be as a data.
+                */
+               ext4_es_find_delayed_extent_range(inode, last, last, &es);
+               if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) {
+                       if (last != start)
+                               dataoff = (loff_t)last << blkbits;
                        break;
                }
-               for (i = 0; i < fie.fi_extents_mapped; i++) {
-                       next = (loff_t)(ext[i].fe_length + ext[i].fe_logical);
 
-                       if (offset < (loff_t)ext[i].fe_logical)
-                               offset = (loff_t)ext[i].fe_logical;
-                       /*
-                        * If extent is not unwritten, then it contains valid
-                        * data, mapped or delayed.
-                        */
-                       if (!(ext[i].fe_flags & FIEMAP_EXTENT_UNWRITTEN))
-                               goto out;
+               /*
+                * If there is a unwritten extent at this offset,
+                * it will be as a data or a hole according to page
+                * cache that has data or not.
+                */
+               if (map.m_flags & EXT4_MAP_UNWRITTEN) {
+                       int unwritten;
+                       unwritten = ext4_find_unwritten_pgoff(inode, SEEK_DATA,
+                                                             &map, &dataoff);
+                       if (unwritten)
+                               break;
+               }
 
-                       /*
-                        * If there is a unwritten extent at this offset,
-                        * it will be as a data or a hole according to page
-                        * cache that has data or not.
-                        */
-                       if (ext4_find_unwritten_pgoff(inode, SEEK_DATA,
-                                                     next, &offset))
-                               goto out;
+               last++;
+               dataoff = (loff_t)last << blkbits;
+       } while (last <= end);
 
-                       if (ext[i].fe_flags & FIEMAP_EXTENT_LAST) {
-                               ret = -ENXIO;
-                               goto out;
-                       }
-                       offset = next;
-               }
-       }
-       if (offset > inode->i_size)
-               offset = inode->i_size;
-out:
        mutex_unlock(&inode->i_mutex);
-       if (ret)
-               return ret;
 
-       return vfs_setpos(file, offset, maxsize);
+       if (dataoff > isize)
+               return -ENXIO;
+
+       return vfs_setpos(file, dataoff, maxsize);
 }
 
 /*
- * ext4_seek_hole() retrieves the offset for SEEK_HOLE
+ * ext4_seek_hole() retrieves the offset for SEEK_HOLE.
  */
 static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
 {
        struct inode *inode = file->f_mapping->host;
-       struct fiemap_extent_info fie;
-       struct fiemap_extent ext[2];
-       loff_t next;
-       int i, ret = 0;
+       struct ext4_map_blocks map;
+       struct extent_status es;
+       ext4_lblk_t start, last, end;
+       loff_t holeoff, isize;
+       int blkbits;
+       int ret = 0;
 
        mutex_lock(&inode->i_mutex);
-       if (offset >= inode->i_size) {
+
+       isize = i_size_read(inode);
+       if (offset >= isize) {
                mutex_unlock(&inode->i_mutex);
                return -ENXIO;
        }
 
-       fie.fi_flags = 0;
-       fie.fi_extents_max = 2;
-       fie.fi_extents_start = (struct fiemap_extent __user *)&ext;
-       while (1) {
-               mm_segment_t old_fs = get_fs();
-
-               fie.fi_extents_mapped = 0;
-               memset(ext, 0, sizeof(*ext));
+       blkbits = inode->i_sb->s_blocksize_bits;
+       start = offset >> blkbits;
+       last = start;
+       end = isize >> blkbits;
+       holeoff = offset;
 
-               set_fs(get_ds());
-               ret = ext4_fiemap(inode, &fie, offset, maxsize - offset);
-               set_fs(old_fs);
-               if (ret)
-                       break;
+       do {
+               map.m_lblk = last;
+               map.m_len = end - last + 1;
+               ret = ext4_map_blocks(NULL, inode, &map, 0);
+               if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) {
+                       last += ret;
+                       holeoff = (loff_t)last << blkbits;
+                       continue;
+               }
 
-               /* No extents found */
-               if (!fie.fi_extents_mapped)
-                       break;
+               /*
+                * If there is a delay extent at this offset,
+                * we will skip this extent.
+                */
+               ext4_es_find_delayed_extent_range(inode, last, last, &es);
+               if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) {
+                       last = es.es_lblk + es.es_len;
+                       holeoff = (loff_t)last << blkbits;
+                       continue;
+               }
 
-               for (i = 0; i < fie.fi_extents_mapped; i++) {
-                       next = (loff_t)(ext[i].fe_logical + ext[i].fe_length);
-                       /*
-                        * If extent is not unwritten, then it contains valid
-                        * data, mapped or delayed.
-                        */
-                       if (!(ext[i].fe_flags & FIEMAP_EXTENT_UNWRITTEN)) {
-                               if (offset < (loff_t)ext[i].fe_logical)
-                                       goto out;
-                               offset = next;
+               /*
+                * If there is a unwritten extent at this offset,
+                * it will be as a data or a hole according to page
+                * cache that has data or not.
+                */
+               if (map.m_flags & EXT4_MAP_UNWRITTEN) {
+                       int unwritten;
+                       unwritten = ext4_find_unwritten_pgoff(inode, SEEK_HOLE,
+                                                             &map, &holeoff);
+                       if (!unwritten) {
+                               last += ret;
+                               holeoff = (loff_t)last << blkbits;
                                continue;
                        }
-                       /*
-                        * If there is a unwritten extent at this offset,
-                        * it will be as a data or a hole according to page
-                        * cache that has data or not.
-                        */
-                       if (ext4_find_unwritten_pgoff(inode, SEEK_HOLE,
-                                                     next, &offset))
-                               goto out;
-
-                       offset = next;
-                       if (ext[i].fe_flags & FIEMAP_EXTENT_LAST)
-                               goto out;
                }
-       }
-       if (offset > inode->i_size)
-               offset = inode->i_size;
-out:
+
+               /* find a hole */
+               break;
+       } while (last <= end);
+
        mutex_unlock(&inode->i_mutex);
-       if (ret)
-               return ret;
 
-       return vfs_setpos(file, offset, maxsize);
+       if (holeoff > isize)
+               holeoff = isize;
+
+       return vfs_setpos(file, holeoff, maxsize);
 }
 
 /*