linux/fs/ext4/migrate.c

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/*
* Copyright IBM Corporation, 2007
* Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2.1 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
*/
#include <linux/module.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include "ext4_jbd2.h"
#include "ext4_extents.h"
/*
* The contiguous blocks details which can be
* represented by a single extent
*/
struct list_blocks_struct {
ext4_lblk_t first_block, last_block;
ext4_fsblk_t first_pblock, last_pblock;
};
static int finish_range(handle_t *handle, struct inode *inode,
struct list_blocks_struct *lb)
{
int retval = 0, needed;
struct ext4_extent newext;
struct ext4_ext_path *path;
if (lb->first_pblock == 0)
return 0;
/* Add the extent to temp inode*/
newext.ee_block = cpu_to_le32(lb->first_block);
newext.ee_len = cpu_to_le16(lb->last_block - lb->first_block + 1);
ext4_ext_store_pblock(&newext, lb->first_pblock);
path = ext4_ext_find_extent(inode, lb->first_block, NULL);
if (IS_ERR(path)) {
retval = PTR_ERR(path);
path = NULL;
goto err_out;
}
/*
* Calculate the credit needed to inserting this extent
* Since we are doing this in loop we may accumalate extra
* credit. But below we try to not accumalate too much
* of them by restarting the journal.
*/
needed = ext4_ext_calc_credits_for_single_extent(inode,
lb->last_block - lb->first_block + 1, path);
/*
* Make sure the credit we accumalated is not really high
*/
if (needed && ext4_handle_has_enough_credits(handle,
EXT4_RESERVE_TRANS_BLOCKS)) {
retval = ext4_journal_restart(handle, needed);
if (retval)
goto err_out;
} else if (needed) {
retval = ext4_journal_extend(handle, needed);
if (retval) {
/*
* IF not able to extend the journal restart the journal
*/
retval = ext4_journal_restart(handle, needed);
if (retval)
goto err_out;
}
}
retval = ext4_ext_insert_extent(handle, inode, path, &newext, 0);
err_out:
if (path) {
ext4_ext_drop_refs(path);
kfree(path);
}
lb->first_pblock = 0;
return retval;
}
static int update_extent_range(handle_t *handle, struct inode *inode,
ext4_fsblk_t pblock, ext4_lblk_t blk_num,
struct list_blocks_struct *lb)
{
int retval;
/*
* See if we can add on to the existing range (if it exists)
*/
if (lb->first_pblock &&
(lb->last_pblock+1 == pblock) &&
(lb->last_block+1 == blk_num)) {
lb->last_pblock = pblock;
lb->last_block = blk_num;
return 0;
}
/*
* Start a new range.
*/
retval = finish_range(handle, inode, lb);
lb->first_pblock = lb->last_pblock = pblock;
lb->first_block = lb->last_block = blk_num;
return retval;
}
static int update_ind_extent_range(handle_t *handle, struct inode *inode,
ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
struct list_blocks_struct *lb)
{
struct buffer_head *bh;
__le32 *i_data;
int i, retval = 0;
ext4_lblk_t blk_count = *blk_nump;
unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
if (!pblock) {
/* Only update the file block number */
*blk_nump += max_entries;
return 0;
}
bh = sb_bread(inode->i_sb, pblock);
if (!bh)
return -EIO;
i_data = (__le32 *)bh->b_data;
for (i = 0; i < max_entries; i++, blk_count++) {
if (i_data[i]) {
retval = update_extent_range(handle, inode,
le32_to_cpu(i_data[i]),
blk_count, lb);
if (retval)
break;
}
}
/* Update the file block number */
*blk_nump = blk_count;
put_bh(bh);
return retval;
}
static int update_dind_extent_range(handle_t *handle, struct inode *inode,
ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
struct list_blocks_struct *lb)
{
struct buffer_head *bh;
__le32 *i_data;
int i, retval = 0;
ext4_lblk_t blk_count = *blk_nump;
unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
if (!pblock) {
/* Only update the file block number */
*blk_nump += max_entries * max_entries;
return 0;
}
bh = sb_bread(inode->i_sb, pblock);
if (!bh)
return -EIO;
i_data = (__le32 *)bh->b_data;
for (i = 0; i < max_entries; i++) {
if (i_data[i]) {
retval = update_ind_extent_range(handle, inode,
le32_to_cpu(i_data[i]),
&blk_count, lb);
if (retval)
break;
} else {
/* Only update the file block number */
blk_count += max_entries;
}
}
/* Update the file block number */
*blk_nump = blk_count;
put_bh(bh);
return retval;
}
static int update_tind_extent_range(handle_t *handle, struct inode *inode,
ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
struct list_blocks_struct *lb)
{
struct buffer_head *bh;
__le32 *i_data;
int i, retval = 0;
ext4_lblk_t blk_count = *blk_nump;
unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
if (!pblock) {
/* Only update the file block number */
*blk_nump += max_entries * max_entries * max_entries;
return 0;
}
bh = sb_bread(inode->i_sb, pblock);
if (!bh)
return -EIO;
i_data = (__le32 *)bh->b_data;
for (i = 0; i < max_entries; i++) {
if (i_data[i]) {
retval = update_dind_extent_range(handle, inode,
le32_to_cpu(i_data[i]),
&blk_count, lb);
if (retval)
break;
} else
/* Only update the file block number */
blk_count += max_entries * max_entries;
}
/* Update the file block number */
*blk_nump = blk_count;
put_bh(bh);
return retval;
}
static int extend_credit_for_blkdel(handle_t *handle, struct inode *inode)
{
int retval = 0, needed;
if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
return 0;
/*
* We are freeing a blocks. During this we touch
* superblock, group descriptor and block bitmap.
* So allocate a credit of 3. We may update
* quota (user and group).
*/
needed = 3 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
if (ext4_journal_extend(handle, needed) != 0)
retval = ext4_journal_restart(handle, needed);
return retval;
}
static int free_dind_blocks(handle_t *handle,
struct inode *inode, __le32 i_data)
{
int i;
__le32 *tmp_idata;
struct buffer_head *bh;
unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
if (!bh)
return -EIO;
tmp_idata = (__le32 *)bh->b_data;
for (i = 0; i < max_entries; i++) {
if (tmp_idata[i]) {
extend_credit_for_blkdel(handle, inode);
ext4_free_blocks(handle, inode, 0,
le32_to_cpu(tmp_idata[i]), 1,
EXT4_FREE_BLOCKS_METADATA |
EXT4_FREE_BLOCKS_FORGET);
}
}
put_bh(bh);
extend_credit_for_blkdel(handle, inode);
ext4_free_blocks(handle, inode, 0, le32_to_cpu(i_data), 1,
EXT4_FREE_BLOCKS_METADATA |
EXT4_FREE_BLOCKS_FORGET);
return 0;
}
static int free_tind_blocks(handle_t *handle,
struct inode *inode, __le32 i_data)
{
int i, retval = 0;
__le32 *tmp_idata;
struct buffer_head *bh;
unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
if (!bh)
return -EIO;
tmp_idata = (__le32 *)bh->b_data;
for (i = 0; i < max_entries; i++) {
if (tmp_idata[i]) {
retval = free_dind_blocks(handle,
inode, tmp_idata[i]);
if (retval) {
put_bh(bh);
return retval;
}
}
}
put_bh(bh);
extend_credit_for_blkdel(handle, inode);
ext4_free_blocks(handle, inode, 0, le32_to_cpu(i_data), 1,
EXT4_FREE_BLOCKS_METADATA |
EXT4_FREE_BLOCKS_FORGET);
return 0;
}
static int free_ind_block(handle_t *handle, struct inode *inode, __le32 *i_data)
{
int retval;
/* ei->i_data[EXT4_IND_BLOCK] */
if (i_data[0]) {
extend_credit_for_blkdel(handle, inode);
ext4_free_blocks(handle, inode, 0,
le32_to_cpu(i_data[0]), 1,
EXT4_FREE_BLOCKS_METADATA |
EXT4_FREE_BLOCKS_FORGET);
}
/* ei->i_data[EXT4_DIND_BLOCK] */
if (i_data[1]) {
retval = free_dind_blocks(handle, inode, i_data[1]);
if (retval)
return retval;
}
/* ei->i_data[EXT4_TIND_BLOCK] */
if (i_data[2]) {
retval = free_tind_blocks(handle, inode, i_data[2]);
if (retval)
return retval;
}
return 0;
}
static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
struct inode *tmp_inode)
{
int retval;
__le32 i_data[3];
struct ext4_inode_info *ei = EXT4_I(inode);
struct ext4_inode_info *tmp_ei = EXT4_I(tmp_inode);
/*
* One credit accounted for writing the
* i_data field of the original inode
*/
retval = ext4_journal_extend(handle, 1);
if (retval) {
retval = ext4_journal_restart(handle, 1);
if (retval)
goto err_out;
}
i_data[0] = ei->i_data[EXT4_IND_BLOCK];
i_data[1] = ei->i_data[EXT4_DIND_BLOCK];
i_data[2] = ei->i_data[EXT4_TIND_BLOCK];
down_write(&EXT4_I(inode)->i_data_sem);
/*
* if EXT4_STATE_EXT_MIGRATE is cleared a block allocation
* happened after we started the migrate. We need to
* fail the migrate
*/
if (!ext4_test_inode_state(inode, EXT4_STATE_EXT_MIGRATE)) {
retval = -EAGAIN;
up_write(&EXT4_I(inode)->i_data_sem);
goto err_out;
} else
ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
/*
* We have the extent map build with the tmp inode.
* Now copy the i_data across
*/
ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS);
memcpy(ei->i_data, tmp_ei->i_data, sizeof(ei->i_data));
/*
* Update i_blocks with the new blocks that got
* allocated while adding extents for extent index
* blocks.
*
* While converting to extents we need not
* update the orignal inode i_blocks for extent blocks
* via quota APIs. The quota update happened via tmp_inode already.
*/
spin_lock(&inode->i_lock);
inode->i_blocks += tmp_inode->i_blocks;
spin_unlock(&inode->i_lock);
up_write(&EXT4_I(inode)->i_data_sem);
/*
* We mark the inode dirty after, because we decrement the
* i_blocks when freeing the indirect meta-data blocks
*/
retval = free_ind_block(handle, inode, i_data);
ext4_mark_inode_dirty(handle, inode);
err_out:
return retval;
}
static int free_ext_idx(handle_t *handle, struct inode *inode,
struct ext4_extent_idx *ix)
{
int i, retval = 0;
ext4_fsblk_t block;
struct buffer_head *bh;
struct ext4_extent_header *eh;
block = ext4_idx_pblock(ix);
bh = sb_bread(inode->i_sb, block);
if (!bh)
return -EIO;
eh = (struct ext4_extent_header *)bh->b_data;
if (eh->eh_depth != 0) {
ix = EXT_FIRST_INDEX(eh);
for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
retval = free_ext_idx(handle, inode, ix);
if (retval)
break;
}
}
put_bh(bh);
extend_credit_for_blkdel(handle, inode);
ext4_free_blocks(handle, inode, 0, block, 1,
EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
return retval;
}
/*
* Free the extent meta data blocks only
*/
static int free_ext_block(handle_t *handle, struct inode *inode)
{
int i, retval = 0;
struct ext4_inode_info *ei = EXT4_I(inode);
struct ext4_extent_header *eh = (struct ext4_extent_header *)ei->i_data;
struct ext4_extent_idx *ix;
if (eh->eh_depth == 0)
/*
* No extra blocks allocated for extent meta data
*/
return 0;
ix = EXT_FIRST_INDEX(eh);
for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
retval = free_ext_idx(handle, inode, ix);
if (retval)
return retval;
}
return retval;
}
int ext4_ext_migrate(struct inode *inode)
{
handle_t *handle;
int retval = 0, i;
__le32 *i_data;
ext4_lblk_t blk_count = 0;
struct ext4_inode_info *ei;
struct inode *tmp_inode = NULL;
struct list_blocks_struct lb;
unsigned long max_entries;
__u32 goal;
/*
* If the filesystem does not support extents, or the inode
* already is extent-based, error out.
*/
if (!EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb,
EXT4_FEATURE_INCOMPAT_EXTENTS) ||
(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
return -EINVAL;
if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0)
/*
* don't migrate fast symlink
*/
return retval;
handle = ext4_journal_start(inode,
EXT4_DATA_TRANS_BLOCKS(inode->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)
+ 1);
if (IS_ERR(handle)) {
retval = PTR_ERR(handle);
return retval;
}
goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) *
EXT4_INODES_PER_GROUP(inode->i_sb)) + 1;
tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
S_IFREG, 0, goal);
if (IS_ERR(tmp_inode)) {
retval = -ENOMEM;
ext4_journal_stop(handle);
return retval;
}
i_size_write(tmp_inode, i_size_read(inode));
/*
* Set the i_nlink to zero so it will be deleted later
* when we drop inode reference.
*/
tmp_inode->i_nlink = 0;
ext4_ext_tree_init(handle, tmp_inode);
ext4_orphan_add(handle, tmp_inode);
ext4_journal_stop(handle);
/*
* start with one credit accounted for
* superblock modification.
*
* For the tmp_inode we already have commited the
* trascation that created the inode. Later as and
* when we add extents we extent the journal
*/
/*
* Even though we take i_mutex we can still cause block
* allocation via mmap write to holes. If we have allocated
* new blocks we fail migrate. New block allocation will
* clear EXT4_STATE_EXT_MIGRATE flag. The flag is updated
* with i_data_sem held to prevent racing with block
* allocation.
*/
down_read((&EXT4_I(inode)->i_data_sem));
ext4_set_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
up_read((&EXT4_I(inode)->i_data_sem));
handle = ext4_journal_start(inode, 1);
if (IS_ERR(handle)) {
/*
* It is impossible to update on-disk structures without
* a handle, so just rollback in-core changes and live other
* work to orphan_list_cleanup()
*/
ext4_orphan_del(NULL, tmp_inode);
retval = PTR_ERR(handle);
goto out;
}
ei = EXT4_I(inode);
i_data = ei->i_data;
memset(&lb, 0, sizeof(lb));
/* 32 bit block address 4 bytes */
max_entries = inode->i_sb->s_blocksize >> 2;
for (i = 0; i < EXT4_NDIR_BLOCKS; i++, blk_count++) {
if (i_data[i]) {
retval = update_extent_range(handle, tmp_inode,
le32_to_cpu(i_data[i]),
blk_count, &lb);
if (retval)
goto err_out;
}
}
if (i_data[EXT4_IND_BLOCK]) {
retval = update_ind_extent_range(handle, tmp_inode,
le32_to_cpu(i_data[EXT4_IND_BLOCK]),
&blk_count, &lb);
if (retval)
goto err_out;
} else
blk_count += max_entries;
if (i_data[EXT4_DIND_BLOCK]) {
retval = update_dind_extent_range(handle, tmp_inode,
le32_to_cpu(i_data[EXT4_DIND_BLOCK]),
&blk_count, &lb);
if (retval)
goto err_out;
} else
blk_count += max_entries * max_entries;
if (i_data[EXT4_TIND_BLOCK]) {
retval = update_tind_extent_range(handle, tmp_inode,
le32_to_cpu(i_data[EXT4_TIND_BLOCK]),
&blk_count, &lb);
if (retval)
goto err_out;
}
/*
* Build the last extent
*/
retval = finish_range(handle, tmp_inode, &lb);
err_out:
if (retval)
/*
* Failure case delete the extent information with the
* tmp_inode
*/
free_ext_block(handle, tmp_inode);
else {
retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode);
if (retval)
/*
* if we fail to swap inode data free the extent
* details of the tmp inode
*/
free_ext_block(handle, tmp_inode);
}
/* We mark the tmp_inode dirty via ext4_ext_tree_init. */
if (ext4_journal_extend(handle, 1) != 0)
ext4_journal_restart(handle, 1);
/*
* Mark the tmp_inode as of size zero
*/
i_size_write(tmp_inode, 0);
/*
* set the i_blocks count to zero
* so that the ext4_delete_inode does the
* right job
*
* We don't need to take the i_lock because
* the inode is not visible to user space.
*/
tmp_inode->i_blocks = 0;
/* Reset the extent details */
ext4_ext_tree_init(handle, tmp_inode);
ext4_journal_stop(handle);
out:
unlock_new_inode(tmp_inode);
iput(tmp_inode);
return retval;
}