From ad7fefb109b0418bb4f16fc1176fd082f986698b Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Fri, 2 Jan 2015 15:16:00 -0500 Subject: [PATCH] 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 --- fs/ext4/extents.c | 4 +- fs/ext4/file.c | 220 ++++++++++++++++++++++++---------------------- 2 files changed, 116 insertions(+), 108 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 @@ static int ext4_find_unwritten_pgoff(struct inode *inode, int whence, 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); } /* -- GitLab