Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 bugfixes from Ted Ts'o:
 "Revert a potential seek_data/hole regression which shows up when using
  ext4 to handle ext3 file systems, plus two minor bug fixes"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: remove spurious KERN_INFO from ext4_warning call
  Revert "ext4: fix suboptimal seek_{data,hole} extents traversial"
  ext4: prevent online resize with backup superblock

4 files changed, 129 insertions, 121 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e5d3eadf47b1..bed43081720f 100644
--- 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 513c12cf444c..8131be8c0af3 100644
--- 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);
 }
 
 /*
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index bf76f405a5f9..8a8ec6293b19 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -24,6 +24,18 @@ int ext4_resize_begin(struct super_block *sb)
                 return -EPERM;
 
         /*
+         * If we are not using the primary superblock/GDT copy don't resize,
+         * because the user tools have no way of handling this.  Probably a
+         * bad time to do it anyways.
+         */
+        if (EXT4_SB(sb)->s_sbh->b_blocknr !=
+            le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
+                ext4_warning(sb, "won't resize using backup superblock at %llu",
+                        (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
+                return -EPERM;
+        }
+
+        /*
          * We are not allowed to do online-resizing on a filesystem mounted
          * with error, because it can destroy the filesystem easily.
          */
@@ -758,18 +770,6 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
                        "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
                        gdb_num);
 
-        /*
-         * If we are not using the primary superblock/GDT copy don't resize,
-         * because the user tools have no way of handling this.  Probably a
-         * bad time to do it anyways.
-         */
-        if (EXT4_SB(sb)->s_sbh->b_blocknr !=
-            le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
-                ext4_warning(sb, "won't resize using backup superblock at %llu",
-                        (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
-                return -EPERM;
-        }
-
         gdb_bh = sb_bread(sb, gdblock);
         if (!gdb_bh)
                 return -EIO;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 43c92b1685cb..74c5f53595fb 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3482,7 +3482,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
-                ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
+                ext4_warning(sb, "metadata_csum and uninit_bg are "
                              "redundant flags; please run fsck.");
 
         /* Check for a known checksum algorithm */