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Diffstat (limited to 'fs/ext4/extents.c')
-rw-r--r--fs/ext4/extents.c170
1 files changed, 88 insertions, 82 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 4394a757aa4..4726a3a447a 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -44,6 +44,14 @@
#include <trace/events/ext4.h>
+/*
+ * used by extent splitting.
+ */
+#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
+ due to ENOSPC */
+#define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */
+#define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */
+
static int ext4_split_extent(handle_t *handle,
struct inode *inode,
struct ext4_ext_path *path,
@@ -51,6 +59,13 @@ static int ext4_split_extent(handle_t *handle,
int split_flag,
int flags);
+static int ext4_split_extent_at(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t split,
+ int split_flag,
+ int flags);
+
static int ext4_ext_truncate_extend_restart(handle_t *handle,
struct inode *inode,
int needed)
@@ -2310,7 +2325,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
struct ext4_extent *ex;
/* the header must be checked already in ext4_ext_remove_space() */
- ext_debug("truncate since %u in leaf\n", start);
+ ext_debug("truncate since %u in leaf to %u\n", start, end);
if (!path[depth].p_hdr)
path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
eh = path[depth].p_hdr;
@@ -2345,7 +2360,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
ext_debug(" border %u:%u\n", a, b);
/* If this extent is beyond the end of the hole, skip it */
- if (end <= ex_ee_block) {
+ if (end < ex_ee_block) {
ex--;
ex_ee_block = le32_to_cpu(ex->ee_block);
ex_ee_len = ext4_ext_get_actual_len(ex);
@@ -2484,7 +2499,8 @@ ext4_ext_more_to_rm(struct ext4_ext_path *path)
return 1;
}
-static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
+static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
+ ext4_lblk_t end)
{
struct super_block *sb = inode->i_sb;
int depth = ext_depth(inode);
@@ -2493,7 +2509,7 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
handle_t *handle;
int i, err;
- ext_debug("truncate since %u\n", start);
+ ext_debug("truncate since %u to %u\n", start, end);
/* probably first extent we're gonna free will be last in block */
handle = ext4_journal_start(inode, depth + 1);
@@ -2506,6 +2522,61 @@ again:
trace_ext4_ext_remove_space(inode, start, depth);
/*
+ * Check if we are removing extents inside the extent tree. If that
+ * is the case, we are going to punch a hole inside the extent tree
+ * so we have to check whether we need to split the extent covering
+ * the last block to remove so we can easily remove the part of it
+ * in ext4_ext_rm_leaf().
+ */
+ if (end < EXT_MAX_BLOCKS - 1) {
+ struct ext4_extent *ex;
+ ext4_lblk_t ee_block;
+
+ /* find extent for this block */
+ path = ext4_ext_find_extent(inode, end, NULL);
+ if (IS_ERR(path)) {
+ ext4_journal_stop(handle);
+ return PTR_ERR(path);
+ }
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ if (!ex)
+ goto cont;
+
+ ee_block = le32_to_cpu(ex->ee_block);
+
+ /*
+ * See if the last block is inside the extent, if so split
+ * the extent at 'end' block so we can easily remove the
+ * tail of the first part of the split extent in
+ * ext4_ext_rm_leaf().
+ */
+ if (end >= ee_block &&
+ end < ee_block + ext4_ext_get_actual_len(ex) - 1) {
+ int split_flag = 0;
+
+ if (ext4_ext_is_uninitialized(ex))
+ split_flag = EXT4_EXT_MARK_UNINIT1 |
+ EXT4_EXT_MARK_UNINIT2;
+
+ /*
+ * Split the extent in two so that 'end' is the last
+ * block in the first new extent
+ */
+ err = ext4_split_extent_at(handle, inode, path,
+ end + 1, split_flag,
+ EXT4_GET_BLOCKS_PRE_IO |
+ EXT4_GET_BLOCKS_PUNCH_OUT_EXT);
+
+ if (err < 0)
+ goto out;
+ }
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ }
+cont:
+
+ /*
* We start scanning from right side, freeing all the blocks
* after i_size and walking into the tree depth-wise.
*/
@@ -2517,6 +2588,7 @@ again:
}
path[0].p_depth = depth;
path[0].p_hdr = ext_inode_hdr(inode);
+
if (ext4_ext_check(inode, path[0].p_hdr, depth)) {
err = -EIO;
goto out;
@@ -2528,7 +2600,7 @@ again:
/* this is leaf block */
err = ext4_ext_rm_leaf(handle, inode, path,
&partial_cluster, start,
- EXT_MAX_BLOCKS - 1);
+ end);
/* root level has p_bh == NULL, brelse() eats this */
brelse(path[i].p_bh);
path[i].p_bh = NULL;
@@ -2711,14 +2783,6 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
}
/*
- * used by extent splitting.
- */
-#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
- due to ENOSPC */
-#define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */
-#define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */
-
-/*
* ext4_split_extent_at() splits an extent at given block.
*
* @handle: the journal handle
@@ -4230,7 +4294,7 @@ void ext4_ext_truncate(struct inode *inode)
last_block = (inode->i_size + sb->s_blocksize - 1)
>> EXT4_BLOCK_SIZE_BITS(sb);
- err = ext4_ext_remove_space(inode, last_block);
+ err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
/* In a multi-transaction truncate, we only make the final
* transaction synchronous.
@@ -4707,14 +4771,12 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
{
struct inode *inode = file->f_path.dentry->d_inode;
struct super_block *sb = inode->i_sb;
- struct ext4_ext_cache cache_ex;
- ext4_lblk_t first_block, last_block, num_blocks, iblock, max_blocks;
+ ext4_lblk_t first_block, stop_block;
struct address_space *mapping = inode->i_mapping;
- struct ext4_map_blocks map;
handle_t *handle;
loff_t first_page, last_page, page_len;
loff_t first_page_offset, last_page_offset;
- int ret, credits, blocks_released, err = 0;
+ int credits, err = 0;
/* No need to punch hole beyond i_size */
if (offset >= inode->i_size)
@@ -4730,10 +4792,6 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
offset;
}
- first_block = (offset + sb->s_blocksize - 1) >>
- EXT4_BLOCK_SIZE_BITS(sb);
- last_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
-
first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
last_page = (offset + length) >> PAGE_CACHE_SHIFT;
@@ -4812,7 +4870,6 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
}
}
-
/*
* If i_size is contained in the last page, we need to
* unmap and zero the partial page after i_size
@@ -4832,73 +4889,22 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
}
}
+ first_block = (offset + sb->s_blocksize - 1) >>
+ EXT4_BLOCK_SIZE_BITS(sb);
+ stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
+
/* If there are no blocks to remove, return now */
- if (first_block >= last_block)
+ if (first_block >= stop_block)
goto out;
down_write(&EXT4_I(inode)->i_data_sem);
ext4_ext_invalidate_cache(inode);
ext4_discard_preallocations(inode);
- /*
- * Loop over all the blocks and identify blocks
- * that need to be punched out
- */
- iblock = first_block;
- blocks_released = 0;
- while (iblock < last_block) {
- max_blocks = last_block - iblock;
- num_blocks = 1;
- memset(&map, 0, sizeof(map));
- map.m_lblk = iblock;
- map.m_len = max_blocks;
- ret = ext4_ext_map_blocks(handle, inode, &map,
- EXT4_GET_BLOCKS_PUNCH_OUT_EXT);
-
- if (ret > 0) {
- blocks_released += ret;
- num_blocks = ret;
- } else if (ret == 0) {
- /*
- * If map blocks could not find the block,
- * then it is in a hole. If the hole was
- * not already cached, then map blocks should
- * put it in the cache. So we can get the hole
- * out of the cache
- */
- memset(&cache_ex, 0, sizeof(cache_ex));
- if ((ext4_ext_check_cache(inode, iblock, &cache_ex)) &&
- !cache_ex.ec_start) {
+ err = ext4_ext_remove_space(inode, first_block, stop_block - 1);
- /* The hole is cached */
- num_blocks = cache_ex.ec_block +
- cache_ex.ec_len - iblock;
-
- } else {
- /* The block could not be identified */
- err = -EIO;
- break;
- }
- } else {
- /* Map blocks error */
- err = ret;
- break;
- }
-
- if (num_blocks == 0) {
- /* This condition should never happen */
- ext_debug("Block lookup failed");
- err = -EIO;
- break;
- }
-
- iblock += num_blocks;
- }
-
- if (blocks_released > 0) {
- ext4_ext_invalidate_cache(inode);
- ext4_discard_preallocations(inode);
- }
+ ext4_ext_invalidate_cache(inode);
+ ext4_discard_preallocations(inode);
if (IS_SYNC(inode))
ext4_handle_sync(handle);