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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-06-10 05:30:17 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-06-10 05:30:17 -0300
commitd635711daa98be86d4c7fd01499c34f566b54ccb (patch)
treeaa5cc3760a27c3d57146498cb82fa549547de06c /fs/ext4/extents.c
parentc91265cd0efb83778f015b4d4b1129bd2cfd075e (diff)
Linux-libre 4.6.2-gnu
Diffstat (limited to 'fs/ext4/extents.c')
-rw-r--r--fs/ext4/extents.c128
1 files changed, 63 insertions, 65 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 3753ceb0b..95bf4679a 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -15,7 +15,7 @@
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
- * You should have received a copy of the GNU General Public Licens
+ * You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
*/
@@ -1736,6 +1736,12 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
*/
if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
return 0;
+ /*
+ * The check for IO to unwritten extent is somewhat racy as we
+ * increment i_unwritten / set EXT4_STATE_DIO_UNWRITTEN only after
+ * dropping i_data_sem. But reserved blocks should save us in that
+ * case.
+ */
if (ext4_ext_is_unwritten(ex1) &&
(ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) ||
atomic_read(&EXT4_I(inode)->i_unwritten) ||
@@ -2293,59 +2299,69 @@ static int ext4_fill_fiemap_extents(struct inode *inode,
}
/*
- * ext4_ext_put_gap_in_cache:
- * calculate boundaries of the gap that the requested block fits into
- * and cache this gap
+ * ext4_ext_determine_hole - determine hole around given block
+ * @inode: inode we lookup in
+ * @path: path in extent tree to @lblk
+ * @lblk: pointer to logical block around which we want to determine hole
+ *
+ * Determine hole length (and start if easily possible) around given logical
+ * block. We don't try too hard to find the beginning of the hole but @path
+ * actually points to extent before @lblk, we provide it.
+ *
+ * The function returns the length of a hole starting at @lblk. We update @lblk
+ * to the beginning of the hole if we managed to find it.
*/
-static void
-ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
- ext4_lblk_t block)
+static ext4_lblk_t ext4_ext_determine_hole(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t *lblk)
{
int depth = ext_depth(inode);
- ext4_lblk_t len;
- ext4_lblk_t lblock;
struct ext4_extent *ex;
- struct extent_status es;
+ ext4_lblk_t len;
ex = path[depth].p_ext;
if (ex == NULL) {
/* there is no extent yet, so gap is [0;-] */
- lblock = 0;
+ *lblk = 0;
len = EXT_MAX_BLOCKS;
- ext_debug("cache gap(whole file):");
- } else if (block < le32_to_cpu(ex->ee_block)) {
- lblock = block;
- len = le32_to_cpu(ex->ee_block) - block;
- ext_debug("cache gap(before): %u [%u:%u]",
- block,
- le32_to_cpu(ex->ee_block),
- ext4_ext_get_actual_len(ex));
- } else if (block >= le32_to_cpu(ex->ee_block)
+ } else if (*lblk < le32_to_cpu(ex->ee_block)) {
+ len = le32_to_cpu(ex->ee_block) - *lblk;
+ } else if (*lblk >= le32_to_cpu(ex->ee_block)
+ ext4_ext_get_actual_len(ex)) {
ext4_lblk_t next;
- lblock = le32_to_cpu(ex->ee_block)
- + ext4_ext_get_actual_len(ex);
+ *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
next = ext4_ext_next_allocated_block(path);
- ext_debug("cache gap(after): [%u:%u] %u",
- le32_to_cpu(ex->ee_block),
- ext4_ext_get_actual_len(ex),
- block);
- BUG_ON(next == lblock);
- len = next - lblock;
+ BUG_ON(next == *lblk);
+ len = next - *lblk;
} else {
BUG();
}
+ return len;
+}
- ext4_es_find_delayed_extent_range(inode, lblock, lblock + len - 1, &es);
+/*
+ * ext4_ext_put_gap_in_cache:
+ * calculate boundaries of the gap that the requested block fits into
+ * and cache this gap
+ */
+static void
+ext4_ext_put_gap_in_cache(struct inode *inode, ext4_lblk_t hole_start,
+ ext4_lblk_t hole_len)
+{
+ struct extent_status es;
+
+ ext4_es_find_delayed_extent_range(inode, hole_start,
+ hole_start + hole_len - 1, &es);
if (es.es_len) {
/* There's delayed extent containing lblock? */
- if (es.es_lblk <= lblock)
+ if (es.es_lblk <= hole_start)
return;
- len = min(es.es_lblk - lblock, len);
+ hole_len = min(es.es_lblk - hole_start, hole_len);
}
- ext_debug(" -> %u:%u\n", lblock, len);
- ext4_es_insert_extent(inode, lblock, len, ~0, EXTENT_STATUS_HOLE);
+ ext_debug(" -> %u:%u\n", hole_start, hole_len);
+ ext4_es_insert_extent(inode, hole_start, hole_len, ~0,
+ EXTENT_STATUS_HOLE);
}
/*
@@ -3927,7 +3943,7 @@ get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
static int
convert_initialized_extent(handle_t *handle, struct inode *inode,
struct ext4_map_blocks *map,
- struct ext4_ext_path **ppath, int flags,
+ struct ext4_ext_path **ppath,
unsigned int allocated)
{
struct ext4_ext_path *path = *ppath;
@@ -4007,7 +4023,6 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
struct ext4_ext_path *path = *ppath;
int ret = 0;
int err = 0;
- ext4_io_end_t *io = ext4_inode_aio(inode);
ext_debug("ext4_ext_handle_unwritten_extents: inode %lu, logical "
"block %llu, max_blocks %u, flags %x, allocated %u\n",
@@ -4030,15 +4045,6 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
flags | EXT4_GET_BLOCKS_CONVERT);
if (ret <= 0)
goto out;
- /*
- * Flag the inode(non aio case) or end_io struct (aio case)
- * that this IO needs to conversion to written when IO is
- * completed
- */
- if (io)
- ext4_set_io_unwritten_flag(inode, io);
- else
- ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
map->m_flags |= EXT4_MAP_UNWRITTEN;
goto out;
}
@@ -4283,9 +4289,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
unsigned int allocated = 0, offset = 0;
unsigned int allocated_clusters = 0;
struct ext4_allocation_request ar;
- ext4_io_end_t *io = ext4_inode_aio(inode);
ext4_lblk_t cluster_offset;
- int set_unwritten = 0;
bool map_from_cluster = false;
ext_debug("blocks %u/%u requested for inode %lu\n",
@@ -4347,7 +4351,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
(flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
allocated = convert_initialized_extent(
handle, inode, map, &path,
- flags, allocated);
+ allocated);
goto out2;
} else if (!ext4_ext_is_unwritten(ex))
goto out;
@@ -4368,11 +4372,22 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
* we couldn't try to create block if create flag is zero
*/
if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
+ ext4_lblk_t hole_start, hole_len;
+
+ hole_start = map->m_lblk;
+ hole_len = ext4_ext_determine_hole(inode, path, &hole_start);
/*
* put just found gap into cache to speed up
* subsequent requests
*/
- ext4_ext_put_gap_in_cache(inode, path, map->m_lblk);
+ ext4_ext_put_gap_in_cache(inode, hole_start, hole_len);
+
+ /* Update hole_len to reflect hole size after map->m_lblk */
+ if (hole_start != map->m_lblk)
+ hole_len -= map->m_lblk - hole_start;
+ map->m_pblk = 0;
+ map->m_len = min_t(unsigned int, map->m_len, hole_len);
+
goto out2;
}
@@ -4482,15 +4497,6 @@ got_allocated_blocks:
if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT){
ext4_ext_mark_unwritten(&newex);
map->m_flags |= EXT4_MAP_UNWRITTEN;
- /*
- * io_end structure was created for every IO write to an
- * unwritten extent. To avoid unnecessary conversion,
- * here we flag the IO that really needs the conversion.
- * For non asycn direct IO case, flag the inode state
- * that we need to perform conversion when IO is done.
- */
- if (flags & EXT4_GET_BLOCKS_PRE_IO)
- set_unwritten = 1;
}
err = 0;
@@ -4501,14 +4507,6 @@ got_allocated_blocks:
err = ext4_ext_insert_extent(handle, inode, &path,
&newex, flags);
- if (!err && set_unwritten) {
- if (io)
- ext4_set_io_unwritten_flag(inode, io);
- else
- ext4_set_inode_state(inode,
- EXT4_STATE_DIO_UNWRITTEN);
- }
-
if (err && free_on_err) {
int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;