#include <trace/events/ext4.h>
+static int ext4_split_extent(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_map_blocks *map,
+ int split_flag,
+ int flags);
+
static int ext4_ext_truncate_extend_restart(handle_t *handle,
struct inode *inode,
int needed)
static ext4_fsblk_t
ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
struct ext4_ext_path *path,
- struct ext4_extent *ex, int *err)
+ struct ext4_extent *ex, int *err, unsigned int flags)
{
ext4_fsblk_t goal, newblock;
goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
- newblock = ext4_new_meta_blocks(handle, inode, goal, NULL, err);
+ newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
+ NULL, err);
return newblock;
}
* - initializes subtree
*/
static int ext4_ext_split(handle_t *handle, struct inode *inode,
- struct ext4_ext_path *path,
- struct ext4_extent *newext, int at)
+ unsigned int flags,
+ struct ext4_ext_path *path,
+ struct ext4_extent *newext, int at)
{
struct buffer_head *bh = NULL;
int depth = ext_depth(inode);
ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
for (a = 0; a < depth - at; a++) {
newblock = ext4_ext_new_meta_block(handle, inode, path,
- newext, &err);
+ newext, &err, flags);
if (newblock == 0)
goto cleanup;
ablocks[a] = newblock;
* just created block
*/
static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
- struct ext4_ext_path *path,
- struct ext4_extent *newext)
+ unsigned int flags,
+ struct ext4_ext_path *path,
+ struct ext4_extent *newext)
{
struct ext4_ext_path *curp = path;
struct ext4_extent_header *neh;
ext4_fsblk_t newblock;
int err = 0;
- newblock = ext4_ext_new_meta_block(handle, inode, path, newext, &err);
+ newblock = ext4_ext_new_meta_block(handle, inode, path,
+ newext, &err, flags);
if (newblock == 0)
return err;
* if no free index is found, then it requests in-depth growing.
*/
static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
- struct ext4_ext_path *path,
- struct ext4_extent *newext)
+ unsigned int flags,
+ struct ext4_ext_path *path,
+ struct ext4_extent *newext)
{
struct ext4_ext_path *curp;
int depth, i, err = 0;
if (EXT_HAS_FREE_INDEX(curp)) {
/* if we found index with free entry, then use that
* entry: create all needed subtree and add new leaf */
- err = ext4_ext_split(handle, inode, path, newext, i);
+ err = ext4_ext_split(handle, inode, flags, path, newext, i);
if (err)
goto out;
err = PTR_ERR(path);
} else {
/* tree is full, time to grow in depth */
- err = ext4_ext_grow_indepth(handle, inode, path, newext);
+ err = ext4_ext_grow_indepth(handle, inode, flags,
+ path, newext);
if (err)
goto out;
int depth, len, err;
ext4_lblk_t next;
unsigned uninitialized = 0;
+ int flags = 0;
if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
* There is no free space in the found leaf.
* We're gonna add a new leaf in the tree.
*/
- err = ext4_ext_create_new_leaf(handle, inode, path, newext);
+ if (flag & EXT4_GET_BLOCKS_PUNCH_OUT_EXT)
+ flags = EXT4_MB_USE_ROOT_BLOCKS;
+ err = ext4_ext_create_new_leaf(handle, inode, flags, path, newext);
if (err)
goto cleanup;
depth = ext_depth(inode);
}
/*
+ * ext4_ext_in_cache()
+ * Checks to see if the given block is in the cache.
+ * If it is, the cached extent is stored in the given
+ * cache extent pointer. If the cached extent is a hole,
+ * this routine should be used instead of
+ * ext4_ext_in_cache if the calling function needs to
+ * know the size of the hole.
+ *
+ * @inode: The files inode
+ * @block: The block to look for in the cache
+ * @ex: Pointer where the cached extent will be stored
+ * if it contains block
+ *
* Return 0 if cache is invalid; 1 if the cache is valid
*/
-static int
-ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
- struct ext4_extent *ex)
-{
+static int ext4_ext_check_cache(struct inode *inode, ext4_lblk_t block,
+ struct ext4_ext_cache *ex){
struct ext4_ext_cache *cex;
+ struct ext4_sb_info *sbi;
int ret = 0;
/*
*/
spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
cex = &EXT4_I(inode)->i_cached_extent;
+ sbi = EXT4_SB(inode->i_sb);
/* has cache valid data? */
if (cex->ec_len == 0)
goto errout;
if (in_range(block, cex->ec_block, cex->ec_len)) {
- ex->ee_block = cpu_to_le32(cex->ec_block);
- ext4_ext_store_pblock(ex, cex->ec_start);
- ex->ee_len = cpu_to_le16(cex->ec_len);
+ memcpy(ex, cex, sizeof(struct ext4_ext_cache));
ext_debug("%u cached by %u:%u:%llu\n",
block,
cex->ec_block, cex->ec_len, cex->ec_start);
ret = 1;
}
errout:
+ if (!ret)
+ sbi->extent_cache_misses++;
+ else
+ sbi->extent_cache_hits++;
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
return ret;
}
+/*
+ * ext4_ext_in_cache()
+ * Checks to see if the given block is in the cache.
+ * If it is, the cached extent is stored in the given
+ * extent pointer.
+ *
+ * @inode: The files inode
+ * @block: The block to look for in the cache
+ * @ex: Pointer where the cached extent will be stored
+ * if it contains block
+ *
+ * Return 0 if cache is invalid; 1 if the cache is valid
+ */
+static int
+ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
+ struct ext4_extent *ex)
+{
+ struct ext4_ext_cache cex;
+ int ret = 0;
+
+ if (ext4_ext_check_cache(inode, block, &cex)) {
+ ex->ee_block = cpu_to_le32(cex.ec_block);
+ ext4_ext_store_pblock(ex, cex.ec_start);
+ ex->ee_len = cpu_to_le16(cex.ec_len);
+ ret = 1;
+ }
+
+ return ret;
+}
+
+
/*
* ext4_ext_rm_idx:
* removes index from the index block.
ext4_free_blocks(handle, inode, NULL, start, num, flags);
} else if (from == le32_to_cpu(ex->ee_block)
&& to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
- printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n",
- from, to, le32_to_cpu(ex->ee_block), ee_len);
+ /* head removal */
+ ext4_lblk_t num;
+ ext4_fsblk_t start;
+
+ num = to - from;
+ start = ext4_ext_pblock(ex);
+
+ ext_debug("free first %u blocks starting %llu\n", num, start);
+ ext4_free_blocks(handle, inode, 0, start, num, flags);
+
} else {
printk(KERN_INFO "strange request: removal(2) "
"%u-%u from %u:%u\n",
return 0;
}
+
+/*
+ * ext4_ext_rm_leaf() Removes the extents associated with the
+ * blocks appearing between "start" and "end", and splits the extents
+ * if "start" and "end" appear in the same extent
+ *
+ * @handle: The journal handle
+ * @inode: The files inode
+ * @path: The path to the leaf
+ * @start: The first block to remove
+ * @end: The last block to remove
+ */
static int
ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
- struct ext4_ext_path *path, ext4_lblk_t start)
+ struct ext4_ext_path *path, ext4_lblk_t start,
+ ext4_lblk_t end)
{
int err = 0, correct_index = 0;
int depth = ext_depth(inode), credits;
unsigned short ex_ee_len;
unsigned uninitialized = 0;
struct ext4_extent *ex;
+ struct ext4_map_blocks map;
/* the header must be checked already in ext4_ext_remove_space() */
ext_debug("truncate since %u in leaf\n", start);
path[depth].p_ext = ex;
a = ex_ee_block > start ? ex_ee_block : start;
- b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ?
- ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK;
+ b = ex_ee_block+ex_ee_len - 1 < end ?
+ ex_ee_block+ex_ee_len - 1 : end;
ext_debug(" border %u:%u\n", a, b);
- if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) {
- block = 0;
- num = 0;
- BUG();
+ /* If this extent is beyond the end of the hole, skip it */
+ if (end <= ex_ee_block) {
+ ex--;
+ ex_ee_block = le32_to_cpu(ex->ee_block);
+ ex_ee_len = ext4_ext_get_actual_len(ex);
+ continue;
+ } else if (a != ex_ee_block &&
+ b != ex_ee_block + ex_ee_len - 1) {
+ /*
+ * If this is a truncate, then this condition should
+ * never happen because at least one of the end points
+ * needs to be on the edge of the extent.
+ */
+ if (end == EXT_MAX_BLOCK) {
+ ext_debug(" bad truncate %u:%u\n",
+ start, end);
+ block = 0;
+ num = 0;
+ err = -EIO;
+ goto out;
+ }
+ /*
+ * else this is a hole punch, so the extent needs to
+ * be split since neither edge of the hole is on the
+ * extent edge
+ */
+ else{
+ map.m_pblk = ext4_ext_pblock(ex);
+ map.m_lblk = ex_ee_block;
+ map.m_len = b - ex_ee_block;
+
+ err = ext4_split_extent(handle,
+ inode, path, &map, 0,
+ EXT4_GET_BLOCKS_PUNCH_OUT_EXT |
+ EXT4_GET_BLOCKS_PRE_IO);
+
+ if (err < 0)
+ goto out;
+
+ ex_ee_len = ext4_ext_get_actual_len(ex);
+
+ b = ex_ee_block+ex_ee_len - 1 < end ?
+ ex_ee_block+ex_ee_len - 1 : end;
+
+ /* Then remove tail of this extent */
+ block = ex_ee_block;
+ num = a - block;
+ }
} else if (a != ex_ee_block) {
/* remove tail of the extent */
block = ex_ee_block;
num = a - block;
} else if (b != ex_ee_block + ex_ee_len - 1) {
/* remove head of the extent */
- block = a;
- num = b - a;
- /* there is no "make a hole" API yet */
- BUG();
+ block = b;
+ num = ex_ee_block + ex_ee_len - b;
+
+ /*
+ * If this is a truncate, this condition
+ * should never happen
+ */
+ if (end == EXT_MAX_BLOCK) {
+ ext_debug(" bad truncate %u:%u\n",
+ start, end);
+ err = -EIO;
+ goto out;
+ }
} else {
/* remove whole extent: excellent! */
block = ex_ee_block;
num = 0;
- BUG_ON(a != ex_ee_block);
- BUG_ON(b != ex_ee_block + ex_ee_len - 1);
+ if (a != ex_ee_block) {
+ ext_debug(" bad truncate %u:%u\n",
+ start, end);
+ err = -EIO;
+ goto out;
+ }
+
+ if (b != ex_ee_block + ex_ee_len - 1) {
+ ext_debug(" bad truncate %u:%u\n",
+ start, end);
+ err = -EIO;
+ goto out;
+ }
}
/*
if (num == 0) {
/* this extent is removed; mark slot entirely unused */
ext4_ext_store_pblock(ex, 0);
- le16_add_cpu(&eh->eh_entries, -1);
+ } else if (block != ex_ee_block) {
+ /*
+ * If this was a head removal, then we need to update
+ * the physical block since it is now at a different
+ * location
+ */
+ ext4_ext_store_pblock(ex, ext4_ext_pblock(ex) + (b-a));
}
ex->ee_block = cpu_to_le32(block);
if (err)
goto out;
+ /*
+ * If the extent was completely released,
+ * we need to remove it from the leaf
+ */
+ if (num == 0) {
+ if (end != EXT_MAX_BLOCK) {
+ /*
+ * For hole punching, we need to scoot all the
+ * extents up when an extent is removed so that
+ * we dont have blank extents in the middle
+ */
+ memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
+ sizeof(struct ext4_extent));
+
+ /* Now get rid of the one at the end */
+ memset(EXT_LAST_EXTENT(eh), 0,
+ sizeof(struct ext4_extent));
+ }
+ le16_add_cpu(&eh->eh_entries, -1);
+ }
+
ext_debug("new extent: %u:%u:%llu\n", block, num,
ext4_ext_pblock(ex));
ex--;
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);
while (i >= 0 && err == 0) {
if (i == depth) {
/* this is leaf block */
- err = ext4_ext_rm_leaf(handle, inode, path, start);
+ err = ext4_ext_rm_leaf(handle, inode, path,
+ start, end);
/* root level has p_bh == NULL, brelse() eats this */
brelse(path[i].p_bh);
path[i].p_bh = NULL;
EXT4_EXT_MARK_UNINIT2;
err = ext4_split_extent_at(handle, inode, path,
map->m_lblk + map->m_len, split_flag1, flags1);
+ if (err)
+ goto out;
}
ext4_ext_drop_refs(path);
(EXT4_EXT_MAY_ZEROOUT & split_flag)) {
/* case 3 */
zero_ex.ee_block =
- cpu_to_le32(map->m_lblk + map->m_len);
- zero_ex.ee_len = cpu_to_le16(allocated - map->m_len);
+ cpu_to_le32(map->m_lblk);
+ zero_ex.ee_len = cpu_to_le16(allocated);
ext4_ext_store_pblock(&zero_ex,
ext4_ext_pblock(ex) + map->m_lblk - ee_block);
err = ext4_ext_zeroout(inode, &zero_ex);
goto out;
}
- allocated = map->m_lblk - ee_block + map->m_len;
-
split_map.m_lblk = ee_block;
- split_map.m_len = allocated;
+ split_map.m_len = map->m_lblk - ee_block + map->m_len;
+ allocated = map->m_len;
}
}
ext4_fsblk_t newblock = 0;
int err = 0, depth, ret;
unsigned int allocated = 0;
+ unsigned int punched_out = 0;
+ unsigned int result = 0;
struct ext4_allocation_request ar;
ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
+ struct ext4_map_blocks punch_map;
ext_debug("blocks %u/%u requested for inode %lu\n",
map->m_lblk, map->m_len, inode->i_ino);
trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
/* check in cache */
- if (ext4_ext_in_cache(inode, map->m_lblk, &newex)) {
+ if (ext4_ext_in_cache(inode, map->m_lblk, &newex) &&
+ ((flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) == 0)) {
if (!newex.ee_start_lo && !newex.ee_start_hi) {
if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
/*
ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
ee_block, ee_len, newblock);
- /* Do not put uninitialized extent in the cache */
- if (!ext4_ext_is_uninitialized(ex)) {
- ext4_ext_put_in_cache(inode, ee_block,
- ee_len, ee_start);
- goto out;
+ if ((flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) == 0) {
+ /*
+ * Do not put uninitialized extent
+ * in the cache
+ */
+ if (!ext4_ext_is_uninitialized(ex)) {
+ ext4_ext_put_in_cache(inode, ee_block,
+ ee_len, ee_start);
+ goto out;
+ }
+ ret = ext4_ext_handle_uninitialized_extents(
+ handle, inode, map, path, flags,
+ allocated, newblock);
+ return ret;
}
- ret = ext4_ext_handle_uninitialized_extents(handle,
- inode, map, path, flags, allocated,
- newblock);
- return ret;
+
+ /*
+ * Punch out the map length, but only to the
+ * end of the extent
+ */
+ punched_out = allocated < map->m_len ?
+ allocated : map->m_len;
+
+ /*
+ * Sense extents need to be converted to
+ * uninitialized, they must fit in an
+ * uninitialized extent
+ */
+ if (punched_out > EXT_UNINIT_MAX_LEN)
+ punched_out = EXT_UNINIT_MAX_LEN;
+
+ punch_map.m_lblk = map->m_lblk;
+ punch_map.m_pblk = newblock;
+ punch_map.m_len = punched_out;
+ punch_map.m_flags = 0;
+
+ /* Check to see if the extent needs to be split */
+ if (punch_map.m_len != ee_len ||
+ punch_map.m_lblk != ee_block) {
+
+ ret = ext4_split_extent(handle, inode,
+ path, &punch_map, 0,
+ EXT4_GET_BLOCKS_PUNCH_OUT_EXT |
+ EXT4_GET_BLOCKS_PRE_IO);
+
+ if (ret < 0) {
+ err = ret;
+ goto out2;
+ }
+ /*
+ * find extent for the block at
+ * the start of the hole
+ */
+ ext4_ext_drop_refs(path);
+ kfree(path);
+
+ path = ext4_ext_find_extent(inode,
+ map->m_lblk, NULL);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ path = NULL;
+ goto out2;
+ }
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_len = ext4_ext_get_actual_len(ex);
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_start = ext4_ext_pblock(ex);
+
+ }
+
+ ext4_ext_mark_uninitialized(ex);
+
+ err = ext4_ext_remove_space(inode, map->m_lblk,
+ map->m_lblk + punched_out);
+
+ goto out2;
}
}
}
trace_ext4_ext_map_blocks_exit(inode, map->m_lblk,
newblock, map->m_len, err ? err : allocated);
- return err ? err : allocated;
+
+ result = (flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) ?
+ punched_out : allocated;
+
+ return err ? err : result;
}
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_BLOCK);
/* In a multi-transaction truncate, we only make the final
* transaction synchronous.
if (IS_SYNC(inode))
ext4_handle_sync(handle);
-out_stop:
up_write(&EXT4_I(inode)->i_data_sem);
+
+out_stop:
/*
* If this was a simple ftruncate() and the file will remain alive,
* then we need to clear up the orphan record which we created above.
struct ext4_map_blocks map;
unsigned int credits, blkbits = inode->i_blkbits;
- /* We only support the FALLOC_FL_KEEP_SIZE mode */
- if (mode & ~FALLOC_FL_KEEP_SIZE)
- return -EOPNOTSUPP;
-
/*
* currently supporting (pre)allocate mode for extent-based
* files _only_
if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
return -EOPNOTSUPP;
+ /* Return error if mode is not supported */
+ if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
+ return -EOPNOTSUPP;
+
+ if (mode & FALLOC_FL_PUNCH_HOLE)
+ return ext4_punch_hole(file, offset, len);
+
trace_ext4_fallocate_enter(inode, offset, len, mode);
map.m_lblk = offset >> blkbits;
/*
pgoff_t last_offset;
pgoff_t offset;
pgoff_t index;
+ pgoff_t start_index = 0;
struct page **pages = NULL;
struct buffer_head *bh = NULL;
struct buffer_head *head = NULL;
kfree(pages);
return EXT_CONTINUE;
}
+ index = 0;
+next_page:
/* Try to find the 1st mapped buffer. */
- end = ((__u64)pages[0]->index << PAGE_SHIFT) >>
+ end = ((__u64)pages[index]->index << PAGE_SHIFT) >>
blksize_bits;
- if (!page_has_buffers(pages[0]))
+ if (!page_has_buffers(pages[index]))
goto out;
- head = page_buffers(pages[0]);
+ head = page_buffers(pages[index]);
if (!head)
goto out;
+ index++;
bh = head;
do {
- if (buffer_mapped(bh)) {
+ if (end >= newex->ec_block +
+ newex->ec_len)
+ /* The buffer is out of
+ * the request range.
+ */
+ goto out;
+
+ if (buffer_mapped(bh) &&
+ end >= newex->ec_block) {
+ start_index = index - 1;
/* get the 1st mapped buffer. */
- if (end > newex->ec_block +
- newex->ec_len)
- /* The buffer is out of
- * the request range.
- */
- goto out;
goto found_mapped_buffer;
}
+
bh = bh->b_this_page;
end++;
} while (bh != head);
- /* No mapped buffer found. */
- goto out;
+ /* No mapped buffer in the range found in this page,
+ * We need to look up next page.
+ */
+ if (index >= ret) {
+ /* There is no page left, but we need to limit
+ * newex->ec_len.
+ */
+ newex->ec_len = end - newex->ec_block;
+ goto out;
+ }
+ goto next_page;
} else {
/*Find contiguous delayed buffers. */
if (ret > 0 && pages[0]->index == last_offset)
head = page_buffers(pages[0]);
bh = head;
+ index = 1;
+ start_index = 0;
}
found_mapped_buffer:
end++;
} while (bh != head);
- for (index = 1; index < ret; index++) {
+ for (; index < ret; index++) {
if (!page_has_buffers(pages[index])) {
bh = NULL;
break;
bh = NULL;
break;
}
+
if (pages[index]->index !=
- pages[0]->index + index) {
+ pages[start_index]->index + index
+ - start_index) {
/* Blocks are not contiguous. */
bh = NULL;
break;
return (error < 0 ? error : 0);
}
+/*
+ * ext4_ext_punch_hole
+ *
+ * Punches a hole of "length" bytes in a file starting
+ * at byte "offset"
+ *
+ * @inode: The inode of the file to punch a hole in
+ * @offset: The starting byte offset of the hole
+ * @length: The length of the hole
+ *
+ * Returns the number of blocks removed or negative on err
+ */
+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;
+ struct address_space *mapping = inode->i_mapping;
+ struct ext4_map_blocks map;
+ handle_t *handle;
+ loff_t first_block_offset, last_block_offset, block_len;
+ loff_t first_page, last_page, first_page_offset, last_page_offset;
+ int ret, credits, blocks_released, err = 0;
+
+ first_block = (offset + sb->s_blocksize - 1) >>
+ EXT4_BLOCK_SIZE_BITS(sb);
+ last_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
+
+ first_block_offset = first_block << EXT4_BLOCK_SIZE_BITS(sb);
+ last_block_offset = last_block << EXT4_BLOCK_SIZE_BITS(sb);
+
+ first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ last_page = (offset + length) >> PAGE_CACHE_SHIFT;
+
+ first_page_offset = first_page << PAGE_CACHE_SHIFT;
+ last_page_offset = last_page << PAGE_CACHE_SHIFT;
+
+ /*
+ * Write out all dirty pages to avoid race conditions
+ * Then release them.
+ */
+ if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
+ err = filemap_write_and_wait_range(mapping,
+ first_page_offset == 0 ? 0 : first_page_offset-1,
+ last_page_offset);
+
+ if (err)
+ return err;
+ }
+
+ /* Now release the pages */
+ if (last_page_offset > first_page_offset) {
+ truncate_inode_pages_range(mapping, first_page_offset,
+ last_page_offset-1);
+ }
+
+ /* finish any pending end_io work */
+ ext4_flush_completed_IO(inode);
+
+ credits = ext4_writepage_trans_blocks(inode);
+ handle = ext4_journal_start(inode, credits);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ err = ext4_orphan_add(handle, inode);
+ if (err)
+ goto out;
+
+ /*
+ * Now we need to zero out the un block aligned data.
+ * If the file is smaller than a block, just
+ * zero out the middle
+ */
+ if (first_block > last_block)
+ ext4_block_zero_page_range(handle, mapping, offset, length);
+ else {
+ /* zero out the head of the hole before the first block */
+ block_len = first_block_offset - offset;
+ if (block_len > 0)
+ ext4_block_zero_page_range(handle, mapping,
+ offset, block_len);
+
+ /* zero out the tail of the hole after the last block */
+ block_len = offset + length - last_block_offset;
+ if (block_len > 0) {
+ ext4_block_zero_page_range(handle, mapping,
+ last_block_offset, block_len);
+ }
+ }
+
+ /* If there are no blocks to remove, return now */
+ if (first_block >= last_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) {
+
+ /* 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);
+ }
+
+ if (IS_SYNC(inode))
+ ext4_handle_sync(handle);
+
+ up_write(&EXT4_I(inode)->i_data_sem);
+
+out:
+ ext4_orphan_del(handle, inode);
+ inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+ ext4_mark_inode_dirty(handle, inode);
+ ext4_journal_stop(handle);
+ return err;
+}
int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
__u64 start, __u64 len)
{
return error;
}
-
git.openpandora.org / pandora-kernel.git / blobdiff