#include <linux/string.h>
#include <linux/buffer_head.h>
#include <linux/writeback.h>
+#include <linux/pagevec.h>
#include <linux/mpage.h>
#include <linux/uio.h>
#include <linux/bio.h>
#include "ext4_jbd2.h"
#include "xattr.h"
#include "acl.h"
+#include "ext4_extents.h"
+
+static inline int ext4_begin_ordered_truncate(struct inode *inode,
+ loff_t new_size)
+{
+ return jbd2_journal_begin_ordered_truncate(&EXT4_I(inode)->jinode,
+ new_size);
+}
+
+static void ext4_invalidatepage(struct page *page, unsigned long offset);
/*
* Test whether an inode is a fast symlink.
{
handle_t *handle;
+ if (ext4_should_order_data(inode))
+ ext4_begin_ordered_truncate(inode, 0);
truncate_inode_pages(&inode->i_data, 0);
if (is_bad_inode(inode))
* direct blocks
*/
static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
- ext4_fsblk_t goal, int indirect_blks, int blks,
- ext4_fsblk_t new_blocks[4], int *err)
+ ext4_lblk_t iblock, ext4_fsblk_t goal,
+ int indirect_blks, int blks,
+ ext4_fsblk_t new_blocks[4], int *err)
{
int target, i;
- unsigned long count = 0;
+ unsigned long count = 0, blk_allocated = 0;
int index = 0;
ext4_fsblk_t current_block = 0;
int ret = 0;
* the first direct block of this branch. That's the
* minimum number of blocks need to allocate(required)
*/
- target = blks + indirect_blks;
-
- while (1) {
+ /* first we try to allocate the indirect blocks */
+ target = indirect_blks;
+ while (target > 0) {
count = target;
/* allocating blocks for indirect blocks and direct blocks */
- current_block = ext4_new_blocks(handle,inode,goal,&count,err);
+ current_block = ext4_new_meta_blocks(handle, inode,
+ goal, &count, err);
if (*err)
goto failed_out;
new_blocks[index++] = current_block++;
count--;
}
-
- if (count > 0)
+ if (count > 0) {
+ /*
+ * save the new block number
+ * for the first direct block
+ */
+ new_blocks[index] = current_block;
+ printk(KERN_INFO "%s returned more blocks than "
+ "requested\n", __func__);
+ WARN_ON(1);
break;
+ }
}
- /* save the new block number for the first direct block */
- new_blocks[index] = current_block;
-
+ target = blks - count ;
+ blk_allocated = count;
+ if (!target)
+ goto allocated;
+ /* Now allocate data blocks */
+ count = target;
+ /* allocating blocks for data blocks */
+ current_block = ext4_new_blocks(handle, inode, iblock,
+ goal, &count, err);
+ if (*err && (target == blks)) {
+ /*
+ * if the allocation failed and we didn't allocate
+ * any blocks before
+ */
+ goto failed_out;
+ }
+ if (!*err) {
+ if (target == blks) {
+ /*
+ * save the new block number
+ * for the first direct block
+ */
+ new_blocks[index] = current_block;
+ }
+ blk_allocated += count;
+ }
+allocated:
/* total number of blocks allocated for direct blocks */
- ret = count;
+ ret = blk_allocated;
*err = 0;
return ret;
failed_out:
* as described above and return 0.
*/
static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
- int indirect_blks, int *blks, ext4_fsblk_t goal,
- ext4_lblk_t *offsets, Indirect *branch)
+ ext4_lblk_t iblock, int indirect_blks,
+ int *blks, ext4_fsblk_t goal,
+ ext4_lblk_t *offsets, Indirect *branch)
{
int blocksize = inode->i_sb->s_blocksize;
int i, n = 0;
ext4_fsblk_t new_blocks[4];
ext4_fsblk_t current_block;
- num = ext4_alloc_blocks(handle, inode, goal, indirect_blks,
+ num = ext4_alloc_blocks(handle, inode, iblock, goal, indirect_blks,
*blks, new_blocks, &err);
if (err)
return err;
/*
* Block out ext4_truncate while we alter the tree
*/
- err = ext4_alloc_branch(handle, inode, indirect_blks, &count, goal,
- offsets + (partial - chain), partial);
+ err = ext4_alloc_branch(handle, inode, iblock, indirect_blks,
+ &count, goal,
+ offsets + (partial - chain), partial);
/*
* The ext4_splice_branch call will free and forget any buffers
*/
int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
unsigned long max_blocks, struct buffer_head *bh,
- int create, int extend_disksize)
+ int create, int extend_disksize, int flag)
{
int retval;
* with create == 1 flag.
*/
down_write((&EXT4_I(inode)->i_data_sem));
+
+ /*
+ * if the caller is from delayed allocation writeout path
+ * we have already reserved fs blocks for allocation
+ * let the underlying get_block() function know to
+ * avoid double accounting
+ */
+ if (flag)
+ EXT4_I(inode)->i_delalloc_reserved_flag = 1;
/*
* We need to check for EXT4 here because migrate
* could have changed the inode type in between
~EXT4_EXT_MIGRATE;
}
}
+
+ if (flag) {
+ EXT4_I(inode)->i_delalloc_reserved_flag = 0;
+ /*
+ * Update reserved blocks/metadata blocks
+ * after successful block allocation
+ * which were deferred till now
+ */
+ if ((retval > 0) && buffer_delay(bh))
+ ext4_da_release_space(inode, retval, 0);
+ }
+
up_write((&EXT4_I(inode)->i_data_sem));
return retval;
}
}
ret = ext4_get_blocks_wrap(handle, inode, iblock,
- max_blocks, bh_result, create, 0);
+ max_blocks, bh_result, create, 0, 0);
if (ret > 0) {
bh_result->b_size = (ret << inode->i_blkbits);
ret = 0;
dummy.b_blocknr = -1000;
buffer_trace_init(&dummy.b_history);
err = ext4_get_blocks_wrap(handle, inode, block, 1,
- &dummy, create, 1);
+ &dummy, create, 1, 0);
/*
* ext4_get_blocks_handle() returns number of blocks
* mapped. 0 in case of a HOLE.
to = from + len;
retry:
- page = __grab_cache_page(mapping, index);
- if (!page)
- return -ENOMEM;
- *pagep = page;
-
handle = ext4_journal_start(inode, needed_blocks);
if (IS_ERR(handle)) {
- unlock_page(page);
- page_cache_release(page);
ret = PTR_ERR(handle);
goto out;
}
+ page = __grab_cache_page(mapping, index);
+ if (!page) {
+ ext4_journal_stop(handle);
+ ret = -ENOMEM;
+ goto out;
+ }
+ *pagep = page;
+
ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
ext4_get_block);
}
if (ret) {
- ext4_journal_stop(handle);
unlock_page(page);
+ ext4_journal_stop(handle);
page_cache_release(page);
}
return ret;
}
-int ext4_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
-{
- int err = jbd2_journal_dirty_data(handle, bh);
- if (err)
- ext4_journal_abort_handle(__func__, __func__,
- bh, handle, err);
- return err;
-}
-
/* For write_end() in data=journal mode */
static int write_end_fn(handle_t *handle, struct buffer_head *bh)
{
return ext4_journal_dirty_metadata(handle, bh);
}
-/*
- * Generic write_end handler for ordered and writeback ext4 journal modes.
- * We can't use generic_write_end, because that unlocks the page and we need to
- * unlock the page after ext4_journal_stop, but ext4_journal_stop must run
- * after block_write_end.
- */
-static int ext4_generic_write_end(struct file *file,
- struct address_space *mapping,
- loff_t pos, unsigned len, unsigned copied,
- struct page *page, void *fsdata)
-{
- struct inode *inode = file->f_mapping->host;
-
- copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
-
- if (pos+copied > inode->i_size) {
- i_size_write(inode, pos+copied);
- mark_inode_dirty(inode);
- }
-
- return copied;
-}
-
/*
* We need to pick up the new inode size which generic_commit_write gave us
* `file' can be NULL - eg, when called from page_symlink().
struct page *page, void *fsdata)
{
handle_t *handle = ext4_journal_current_handle();
- struct inode *inode = file->f_mapping->host;
+ struct inode *inode = mapping->host;
unsigned from, to;
int ret = 0, ret2;
from = pos & (PAGE_CACHE_SIZE - 1);
to = from + len;
- ret = walk_page_buffers(handle, page_buffers(page),
- from, to, NULL, ext4_journal_dirty_data);
+ ret = ext4_jbd2_file_inode(handle, inode);
if (ret == 0) {
/*
*/
loff_t new_i_size;
- new_i_size = pos + copied;
- if (new_i_size > EXT4_I(inode)->i_disksize)
- EXT4_I(inode)->i_disksize = new_i_size;
- ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
- page, fsdata);
- copied = ret2;
- if (ret2 < 0)
- ret = ret2;
+ new_i_size = pos + copied;
+ if (new_i_size > EXT4_I(inode)->i_disksize)
+ EXT4_I(inode)->i_disksize = new_i_size;
+ ret2 = generic_write_end(file, mapping, pos, len, copied,
+ page, fsdata);
+ copied = ret2;
+ if (ret2 < 0)
+ ret = ret2;
+ }
+ ret2 = ext4_journal_stop(handle);
+ if (!ret)
+ ret = ret2;
+
+ return ret ? ret : copied;
+}
+
+static int ext4_writeback_write_end(struct file *file,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ handle_t *handle = ext4_journal_current_handle();
+ struct inode *inode = mapping->host;
+ int ret = 0, ret2;
+ loff_t new_i_size;
+
+ new_i_size = pos + copied;
+ if (new_i_size > EXT4_I(inode)->i_disksize)
+ EXT4_I(inode)->i_disksize = new_i_size;
+
+ ret2 = generic_write_end(file, mapping, pos, len, copied,
+ page, fsdata);
+ copied = ret2;
+ if (ret2 < 0)
+ ret = ret2;
+
+ ret2 = ext4_journal_stop(handle);
+ if (!ret)
+ ret = ret2;
+
+ return ret ? ret : copied;
+}
+
+static int ext4_journalled_write_end(struct file *file,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ handle_t *handle = ext4_journal_current_handle();
+ struct inode *inode = mapping->host;
+ int ret = 0, ret2;
+ int partial = 0;
+ unsigned from, to;
+
+ from = pos & (PAGE_CACHE_SIZE - 1);
+ to = from + len;
+
+ if (copied < len) {
+ if (!PageUptodate(page))
+ copied = 0;
+ page_zero_new_buffers(page, from+copied, to);
+ }
+
+ ret = walk_page_buffers(handle, page_buffers(page), from,
+ to, &partial, write_end_fn);
+ if (!partial)
+ SetPageUptodate(page);
+ if (pos+copied > inode->i_size)
+ i_size_write(inode, pos+copied);
+ EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
+ if (inode->i_size > EXT4_I(inode)->i_disksize) {
+ EXT4_I(inode)->i_disksize = inode->i_size;
+ ret2 = ext4_mark_inode_dirty(handle, inode);
+ if (!ret)
+ ret = ret2;
+ }
+
+ unlock_page(page);
+ ret2 = ext4_journal_stop(handle);
+ if (!ret)
+ ret = ret2;
+ page_cache_release(page);
+
+ return ret ? ret : copied;
+}
+/*
+ * Calculate the number of metadata blocks need to reserve
+ * to allocate @blocks for non extent file based file
+ */
+static int ext4_indirect_calc_metadata_amount(struct inode *inode, int blocks)
+{
+ int icap = EXT4_ADDR_PER_BLOCK(inode->i_sb);
+ int ind_blks, dind_blks, tind_blks;
+
+ /* number of new indirect blocks needed */
+ ind_blks = (blocks + icap - 1) / icap;
+
+ dind_blks = (ind_blks + icap - 1) / icap;
+
+ tind_blks = 1;
+
+ return ind_blks + dind_blks + tind_blks;
+}
+
+/*
+ * Calculate the number of metadata blocks need to reserve
+ * to allocate given number of blocks
+ */
+static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
+{
+ if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
+ return ext4_ext_calc_metadata_amount(inode, blocks);
+
+ return ext4_indirect_calc_metadata_amount(inode, blocks);
+}
+
+static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ unsigned long md_needed, mdblocks, total = 0;
+
+ /*
+ * recalculate the amount of metadata blocks to reserve
+ * in order to allocate nrblocks
+ * worse case is one extent per block
+ */
+ spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+ total = EXT4_I(inode)->i_reserved_data_blocks + nrblocks;
+ mdblocks = ext4_calc_metadata_amount(inode, total);
+ BUG_ON(mdblocks < EXT4_I(inode)->i_reserved_meta_blocks);
+
+ md_needed = mdblocks - EXT4_I(inode)->i_reserved_meta_blocks;
+ total = md_needed + nrblocks;
+
+ if (ext4_has_free_blocks(sbi, total) < total) {
+ spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+ return -ENOSPC;
+ }
+
+ /* reduce fs free blocks counter */
+ percpu_counter_sub(&sbi->s_freeblocks_counter, total);
+
+ EXT4_I(inode)->i_reserved_data_blocks += nrblocks;
+ EXT4_I(inode)->i_reserved_meta_blocks = mdblocks;
+
+ spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+ return 0; /* success */
+}
+
+void ext4_da_release_space(struct inode *inode, int used, int to_free)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ int total, mdb, mdb_free, release;
+
+ spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+ /* recalculate the number of metablocks still need to be reserved */
+ total = EXT4_I(inode)->i_reserved_data_blocks - used - to_free;
+ mdb = ext4_calc_metadata_amount(inode, total);
+
+ /* figure out how many metablocks to release */
+ BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
+ mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
+
+ /* Account for allocated meta_blocks */
+ mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks;
+
+ release = to_free + mdb_free;
+
+ /* update fs free blocks counter for truncate case */
+ percpu_counter_add(&sbi->s_freeblocks_counter, release);
+
+ /* update per-inode reservations */
+ BUG_ON(used + to_free > EXT4_I(inode)->i_reserved_data_blocks);
+ EXT4_I(inode)->i_reserved_data_blocks -= (used + to_free);
+
+ BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
+ EXT4_I(inode)->i_reserved_meta_blocks = mdb;
+ EXT4_I(inode)->i_allocated_meta_blocks = 0;
+ spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+}
+
+static void ext4_da_page_release_reservation(struct page *page,
+ unsigned long offset)
+{
+ int to_release = 0;
+ struct buffer_head *head, *bh;
+ unsigned int curr_off = 0;
+
+ head = page_buffers(page);
+ bh = head;
+ do {
+ unsigned int next_off = curr_off + bh->b_size;
+
+ if ((offset <= curr_off) && (buffer_delay(bh))) {
+ to_release++;
+ clear_buffer_delay(bh);
+ }
+ curr_off = next_off;
+ } while ((bh = bh->b_this_page) != head);
+ ext4_da_release_space(page->mapping->host, 0, to_release);
+}
+
+/*
+ * Delayed allocation stuff
+ */
+
+struct mpage_da_data {
+ struct inode *inode;
+ struct buffer_head lbh; /* extent of blocks */
+ unsigned long first_page, next_page; /* extent of pages */
+ get_block_t *get_block;
+ struct writeback_control *wbc;
+};
+
+/*
+ * mpage_da_submit_io - walks through extent of pages and try to write
+ * them with __mpage_writepage()
+ *
+ * @mpd->inode: inode
+ * @mpd->first_page: first page of the extent
+ * @mpd->next_page: page after the last page of the extent
+ * @mpd->get_block: the filesystem's block mapper function
+ *
+ * By the time mpage_da_submit_io() is called we expect all blocks
+ * to be allocated. this may be wrong if allocation failed.
+ *
+ * As pages are already locked by write_cache_pages(), we can't use it
+ */
+static int mpage_da_submit_io(struct mpage_da_data *mpd)
+{
+ struct address_space *mapping = mpd->inode->i_mapping;
+ struct mpage_data mpd_pp = {
+ .bio = NULL,
+ .last_block_in_bio = 0,
+ .get_block = mpd->get_block,
+ .use_writepage = 1,
+ };
+ int ret = 0, err, nr_pages, i;
+ unsigned long index, end;
+ struct pagevec pvec;
+
+ BUG_ON(mpd->next_page <= mpd->first_page);
+
+ pagevec_init(&pvec, 0);
+ index = mpd->first_page;
+ end = mpd->next_page - 1;
+
+ while (index <= end) {
+ /* XXX: optimize tail */
+ nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
+ if (nr_pages == 0)
+ break;
+ for (i = 0; i < nr_pages; i++) {
+ struct page *page = pvec.pages[i];
+
+ index = page->index;
+ if (index > end)
+ break;
+ index++;
+
+ err = __mpage_writepage(page, mpd->wbc, &mpd_pp);
+
+ /*
+ * In error case, we have to continue because
+ * remaining pages are still locked
+ * XXX: unlock and re-dirty them?
+ */
+ if (ret == 0)
+ ret = err;
+ }
+ pagevec_release(&pvec);
+ }
+ if (mpd_pp.bio)
+ mpage_bio_submit(WRITE, mpd_pp.bio);
+
+ return ret;
+}
+
+/*
+ * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
+ *
+ * @mpd->inode - inode to walk through
+ * @exbh->b_blocknr - first block on a disk
+ * @exbh->b_size - amount of space in bytes
+ * @logical - first logical block to start assignment with
+ *
+ * the function goes through all passed space and put actual disk
+ * block numbers into buffer heads, dropping BH_Delay
+ */
+static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
+ struct buffer_head *exbh)
+{
+ struct inode *inode = mpd->inode;
+ struct address_space *mapping = inode->i_mapping;
+ int blocks = exbh->b_size >> inode->i_blkbits;
+ sector_t pblock = exbh->b_blocknr, cur_logical;
+ struct buffer_head *head, *bh;
+ unsigned long index, end;
+ struct pagevec pvec;
+ int nr_pages, i;
+
+ index = logical >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ end = (logical + blocks - 1) >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ cur_logical = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+
+ pagevec_init(&pvec, 0);
+
+ while (index <= end) {
+ /* XXX: optimize tail */
+ nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
+ if (nr_pages == 0)
+ break;
+ for (i = 0; i < nr_pages; i++) {
+ struct page *page = pvec.pages[i];
+
+ index = page->index;
+ if (index > end)
+ break;
+ index++;
+
+ BUG_ON(!PageLocked(page));
+ BUG_ON(PageWriteback(page));
+ BUG_ON(!page_has_buffers(page));
+
+ bh = page_buffers(page);
+ head = bh;
+
+ /* skip blocks out of the range */
+ do {
+ if (cur_logical >= logical)
+ break;
+ cur_logical++;
+ } while ((bh = bh->b_this_page) != head);
+
+ do {
+ if (cur_logical >= logical + blocks)
+ break;
+
+ if (buffer_delay(bh)) {
+ bh->b_blocknr = pblock;
+ clear_buffer_delay(bh);
+ } else if (buffer_mapped(bh)) {
+ BUG_ON(bh->b_blocknr != pblock);
+ }
+
+ cur_logical++;
+ pblock++;
+ } while ((bh = bh->b_this_page) != head);
+ }
+ pagevec_release(&pvec);
+ }
+}
+
+
+/*
+ * __unmap_underlying_blocks - just a helper function to unmap
+ * set of blocks described by @bh
+ */
+static inline void __unmap_underlying_blocks(struct inode *inode,
+ struct buffer_head *bh)
+{
+ struct block_device *bdev = inode->i_sb->s_bdev;
+ int blocks, i;
+
+ blocks = bh->b_size >> inode->i_blkbits;
+ for (i = 0; i < blocks; i++)
+ unmap_underlying_metadata(bdev, bh->b_blocknr + i);
+}
+
+/*
+ * mpage_da_map_blocks - go through given space
+ *
+ * @mpd->lbh - bh describing space
+ * @mpd->get_block - the filesystem's block mapper function
+ *
+ * The function skips space we know is already mapped to disk blocks.
+ *
+ * The function ignores errors ->get_block() returns, thus real
+ * error handling is postponed to __mpage_writepage()
+ */
+static void mpage_da_map_blocks(struct mpage_da_data *mpd)
+{
+ struct buffer_head *lbh = &mpd->lbh;
+ int err = 0, remain = lbh->b_size;
+ sector_t next = lbh->b_blocknr;
+ struct buffer_head new;
+
+ /*
+ * We consider only non-mapped and non-allocated blocks
+ */
+ if (buffer_mapped(lbh) && !buffer_delay(lbh))
+ return;
+
+ while (remain) {
+ new.b_state = lbh->b_state;
+ new.b_blocknr = 0;
+ new.b_size = remain;
+ err = mpd->get_block(mpd->inode, next, &new, 1);
+ if (err) {
+ /*
+ * Rather than implement own error handling
+ * here, we just leave remaining blocks
+ * unallocated and try again with ->writepage()
+ */
+ break;
+ }
+ BUG_ON(new.b_size == 0);
+
+ if (buffer_new(&new))
+ __unmap_underlying_blocks(mpd->inode, &new);
+
+ /*
+ * If blocks are delayed marked, we need to
+ * put actual blocknr and drop delayed bit
+ */
+ if (buffer_delay(lbh))
+ mpage_put_bnr_to_bhs(mpd, next, &new);
+
+ /* go for the remaining blocks */
+ next += new.b_size >> mpd->inode->i_blkbits;
+ remain -= new.b_size;
+ }
+}
+
+#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | (1 << BH_Delay))
+
+/*
+ * mpage_add_bh_to_extent - try to add one more block to extent of blocks
+ *
+ * @mpd->lbh - extent of blocks
+ * @logical - logical number of the block in the file
+ * @bh - bh of the block (used to access block's state)
+ *
+ * the function is used to collect contig. blocks in same state
+ */
+static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
+ sector_t logical, struct buffer_head *bh)
+{
+ struct buffer_head *lbh = &mpd->lbh;
+ sector_t next;
+
+ next = lbh->b_blocknr + (lbh->b_size >> mpd->inode->i_blkbits);
+
+ /*
+ * First block in the extent
+ */
+ if (lbh->b_size == 0) {
+ lbh->b_blocknr = logical;
+ lbh->b_size = bh->b_size;
+ lbh->b_state = bh->b_state & BH_FLAGS;
+ return;
+ }
+
+ /*
+ * Can we merge the block to our big extent?
+ */
+ if (logical == next && (bh->b_state & BH_FLAGS) == lbh->b_state) {
+ lbh->b_size += bh->b_size;
+ return;
+ }
+
+ /*
+ * We couldn't merge the block to our extent, so we
+ * need to flush current extent and start new one
+ */
+ mpage_da_map_blocks(mpd);
+
+ /*
+ * Now start a new extent
+ */
+ lbh->b_size = bh->b_size;
+ lbh->b_state = bh->b_state & BH_FLAGS;
+ lbh->b_blocknr = logical;
+}
+
+/*
+ * __mpage_da_writepage - finds extent of pages and blocks
+ *
+ * @page: page to consider
+ * @wbc: not used, we just follow rules
+ * @data: context
+ *
+ * The function finds extents of pages and scan them for all blocks.
+ */
+static int __mpage_da_writepage(struct page *page,
+ struct writeback_control *wbc, void *data)
+{
+ struct mpage_da_data *mpd = data;
+ struct inode *inode = mpd->inode;
+ struct buffer_head *bh, *head, fake;
+ sector_t logical;
+
+ /*
+ * Can we merge this page to current extent?
+ */
+ if (mpd->next_page != page->index) {
+ /*
+ * Nope, we can't. So, we map non-allocated blocks
+ * and start IO on them using __mpage_writepage()
+ */
+ if (mpd->next_page != mpd->first_page) {
+ mpage_da_map_blocks(mpd);
+ mpage_da_submit_io(mpd);
+ }
+
+ /*
+ * Start next extent of pages ...
+ */
+ mpd->first_page = page->index;
+
+ /*
+ * ... and blocks
+ */
+ mpd->lbh.b_size = 0;
+ mpd->lbh.b_state = 0;
+ mpd->lbh.b_blocknr = 0;
+ }
+
+ mpd->next_page = page->index + 1;
+ logical = (sector_t) page->index <<
+ (PAGE_CACHE_SHIFT - inode->i_blkbits);
+
+ if (!page_has_buffers(page)) {
+ /*
+ * There is no attached buffer heads yet (mmap?)
+ * we treat the page asfull of dirty blocks
+ */
+ bh = &fake;
+ bh->b_size = PAGE_CACHE_SIZE;
+ bh->b_state = 0;
+ set_buffer_dirty(bh);
+ set_buffer_uptodate(bh);
+ mpage_add_bh_to_extent(mpd, logical, bh);
+ } else {
+ /*
+ * Page with regular buffer heads, just add all dirty ones
+ */
+ head = page_buffers(page);
+ bh = head;
+ do {
+ BUG_ON(buffer_locked(bh));
+ if (buffer_dirty(bh))
+ mpage_add_bh_to_extent(mpd, logical, bh);
+ logical++;
+ } while ((bh = bh->b_this_page) != head);
+ }
+
+ return 0;
+}
+
+/*
+ * mpage_da_writepages - walk the list of dirty pages of the given
+ * address space, allocates non-allocated blocks, maps newly-allocated
+ * blocks to existing bhs and issue IO them
+ *
+ * @mapping: address space structure to write
+ * @wbc: subtract the number of written pages from *@wbc->nr_to_write
+ * @get_block: the filesystem's block mapper function.
+ *
+ * This is a library function, which implements the writepages()
+ * address_space_operation.
+ *
+ * In order to avoid duplication of logic that deals with partial pages,
+ * multiple bio per page, etc, we find non-allocated blocks, allocate
+ * them with minimal calls to ->get_block() and re-use __mpage_writepage()
+ *
+ * It's important that we call __mpage_writepage() only once for each
+ * involved page, otherwise we'd have to implement more complicated logic
+ * to deal with pages w/o PG_lock or w/ PG_writeback and so on.
+ *
+ * See comments to mpage_writepages()
+ */
+static int mpage_da_writepages(struct address_space *mapping,
+ struct writeback_control *wbc,
+ get_block_t get_block)
+{
+ struct mpage_da_data mpd;
+ int ret;
+
+ if (!get_block)
+ return generic_writepages(mapping, wbc);
+
+ mpd.wbc = wbc;
+ mpd.inode = mapping->host;
+ mpd.lbh.b_size = 0;
+ mpd.lbh.b_state = 0;
+ mpd.lbh.b_blocknr = 0;
+ mpd.first_page = 0;
+ mpd.next_page = 0;
+ mpd.get_block = get_block;
+
+ ret = write_cache_pages(mapping, wbc, __mpage_da_writepage, &mpd);
+
+ /*
+ * Handle last extent of pages
+ */
+ if (mpd.next_page != mpd.first_page) {
+ mpage_da_map_blocks(&mpd);
+ mpage_da_submit_io(&mpd);
+ }
+
+ return ret;
+}
+
+/*
+ * this is a special callback for ->write_begin() only
+ * it's intention is to return mapped block or reserve space
+ */
+static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ int ret = 0;
+
+ BUG_ON(create == 0);
+ BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
+
+ /*
+ * first, we need to know whether the block is allocated already
+ * preallocated blocks are unmapped but should treated
+ * the same as allocated blocks.
+ */
+ ret = ext4_get_blocks_wrap(NULL, inode, iblock, 1, bh_result, 0, 0, 0);
+ if ((ret == 0) && !buffer_delay(bh_result)) {
+ /* the block isn't (pre)allocated yet, let's reserve space */
+ /*
+ * XXX: __block_prepare_write() unmaps passed block,
+ * is it OK?
+ */
+ ret = ext4_da_reserve_space(inode, 1);
+ if (ret)
+ /* not enough space to reserve */
+ return ret;
+
+ map_bh(bh_result, inode->i_sb, 0);
+ set_buffer_new(bh_result);
+ set_buffer_delay(bh_result);
+ } else if (ret > 0) {
+ bh_result->b_size = (ret << inode->i_blkbits);
+ ret = 0;
+ }
+
+ return ret;
+}
+#define EXT4_DELALLOC_RSVED 1
+static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ int ret, needed_blocks = ext4_writepage_trans_blocks(inode);
+ unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
+ loff_t disksize = EXT4_I(inode)->i_disksize;
+ handle_t *handle = NULL;
+
+ if (create) {
+ handle = ext4_journal_start(inode, needed_blocks);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto out;
+ }
+ }
+
+ ret = ext4_get_blocks_wrap(handle, inode, iblock, max_blocks,
+ bh_result, create, 0, EXT4_DELALLOC_RSVED);
+ if (ret > 0) {
+ bh_result->b_size = (ret << inode->i_blkbits);
+
+ /*
+ * Update on-disk size along with block allocation
+ * we don't use 'extend_disksize' as size may change
+ * within already allocated block -bzzz
+ */
+ disksize = ((loff_t) iblock + ret) << inode->i_blkbits;
+ if (disksize > i_size_read(inode))
+ disksize = i_size_read(inode);
+ if (disksize > EXT4_I(inode)->i_disksize) {
+ /*
+ * XXX: replace with spinlock if seen contended -bzzz
+ */
+ down_write(&EXT4_I(inode)->i_data_sem);
+ if (disksize > EXT4_I(inode)->i_disksize)
+ EXT4_I(inode)->i_disksize = disksize;
+ up_write(&EXT4_I(inode)->i_data_sem);
+
+ if (EXT4_I(inode)->i_disksize == disksize) {
+ if (handle == NULL)
+ handle = ext4_journal_start(inode, 1);
+ if (!IS_ERR(handle))
+ ext4_mark_inode_dirty(handle, inode);
+ }
+ }
+
+ ret = 0;
+ }
+
+out:
+ if (handle && !IS_ERR(handle))
+ ext4_journal_stop(handle);
+
+ return ret;
+}
+/* FIXME!! only support data=writeback mode */
+static int ext4_da_writepage(struct page *page,
+ struct writeback_control *wbc)
+{
+ struct inode *inode = page->mapping->host;
+ handle_t *handle = NULL;
+ int ret = 0;
+ int err;
+
+ if (ext4_journal_current_handle())
+ goto out_fail;
+
+ handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto out_fail;
+ }
+
+ if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
+ ret = nobh_writepage(page, ext4_get_block, wbc);
+ else
+ ret = block_write_full_page(page, ext4_get_block, wbc);
+
+ if (!ret && inode->i_size > EXT4_I(inode)->i_disksize) {
+ EXT4_I(inode)->i_disksize = inode->i_size;
+ ext4_mark_inode_dirty(handle, inode);
+ }
+
+ err = ext4_journal_stop(handle);
+ if (!ret)
+ ret = err;
+ return ret;
+
+out_fail:
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+ return ret;
+}
+
+static int ext4_da_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ return mpage_da_writepages(mapping, wbc, ext4_da_get_block_write);
+}
+
+static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ int ret, retries = 0;
+ struct page *page;
+ pgoff_t index;
+ unsigned from, to;
+ struct inode *inode = mapping->host;
+ handle_t *handle;
+
+ index = pos >> PAGE_CACHE_SHIFT;
+ from = pos & (PAGE_CACHE_SIZE - 1);
+ to = from + len;
+
+retry:
+ /*
+ * With delayed allocation, we don't log the i_disksize update
+ * if there is delayed block allocation. But we still need
+ * to journalling the i_disksize update if writes to the end
+ * of file which has an already mapped buffer.
+ */
+ handle = ext4_journal_start(inode, 1);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto out;
+ }
+
+ page = __grab_cache_page(mapping, index);
+ if (!page)
+ return -ENOMEM;
+ *pagep = page;
+
+ ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+ ext4_da_get_block_prep);
+ if (ret < 0) {
+ unlock_page(page);
+ ext4_journal_stop(handle);
+ page_cache_release(page);
}
- ret2 = ext4_journal_stop(handle);
- if (!ret)
- ret = ret2;
- unlock_page(page);
- page_cache_release(page);
- return ret ? ret : copied;
+ if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+ goto retry;
+out:
+ return ret;
}
-static int ext4_writeback_write_end(struct file *file,
+static int ext4_bh_unmapped_or_delay(handle_t *handle, struct buffer_head *bh)
+{
+ return !buffer_mapped(bh) || buffer_delay(bh);
+}
+
+static int ext4_da_write_end(struct file *file,
struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
- handle_t *handle = ext4_journal_current_handle();
- struct inode *inode = file->f_mapping->host;
+ struct inode *inode = mapping->host;
int ret = 0, ret2;
+ handle_t *handle = ext4_journal_current_handle();
loff_t new_i_size;
+ /*
+ * generic_write_end() will run mark_inode_dirty() if i_size
+ * changes. So let's piggyback the i_disksize mark_inode_dirty
+ * into that.
+ */
+
new_i_size = pos + copied;
if (new_i_size > EXT4_I(inode)->i_disksize)
- EXT4_I(inode)->i_disksize = new_i_size;
+ if (!walk_page_buffers(NULL, page_buffers(page),
+ 0, len, NULL, ext4_bh_unmapped_or_delay)){
+ /*
+ * Updating i_disksize when extending file without
+ * needing block allocation
+ */
+ if (ext4_should_order_data(inode))
+ ret = ext4_jbd2_file_inode(handle, inode);
- ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
+ EXT4_I(inode)->i_disksize = new_i_size;
+ }
+ ret2 = generic_write_end(file, mapping, pos, len, copied,
page, fsdata);
copied = ret2;
if (ret2 < 0)
ret = ret2;
-
ret2 = ext4_journal_stop(handle);
if (!ret)
ret = ret2;
- unlock_page(page);
- page_cache_release(page);
return ret ? ret : copied;
}
-static int ext4_journalled_write_end(struct file *file,
- struct address_space *mapping,
- loff_t pos, unsigned len, unsigned copied,
- struct page *page, void *fsdata)
+static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
{
- handle_t *handle = ext4_journal_current_handle();
- struct inode *inode = mapping->host;
- int ret = 0, ret2;
- int partial = 0;
- unsigned from, to;
-
- from = pos & (PAGE_CACHE_SIZE - 1);
- to = from + len;
-
- if (copied < len) {
- if (!PageUptodate(page))
- copied = 0;
- page_zero_new_buffers(page, from+copied, to);
- }
+ /*
+ * Drop reserved blocks
+ */
+ BUG_ON(!PageLocked(page));
+ if (!page_has_buffers(page))
+ goto out;
- ret = walk_page_buffers(handle, page_buffers(page), from,
- to, &partial, write_end_fn);
- if (!partial)
- SetPageUptodate(page);
- if (pos+copied > inode->i_size)
- i_size_write(inode, pos+copied);
- EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
- if (inode->i_size > EXT4_I(inode)->i_disksize) {
- EXT4_I(inode)->i_disksize = inode->i_size;
- ret2 = ext4_mark_inode_dirty(handle, inode);
- if (!ret)
- ret = ret2;
- }
+ ext4_da_page_release_reservation(page, offset);
- ret2 = ext4_journal_stop(handle);
- if (!ret)
- ret = ret2;
- unlock_page(page);
- page_cache_release(page);
+out:
+ ext4_invalidatepage(page, offset);
- return ret ? ret : copied;
+ return;
}
+
/*
* bmap() is special. It gets used by applications such as lilo and by
* the swapper to find the on-disk block of a specific piece of data.
journal_t *journal;
int err;
+ if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
+ test_opt(inode->i_sb, DELALLOC)) {
+ /*
+ * With delalloc we want to sync the file
+ * so that we can make sure we allocate
+ * blocks for file
+ */
+ filemap_write_and_wait(mapping);
+ }
+
if (EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {
/*
* This is a REALLY heavyweight approach, but the use of
return 0;
}
-static int jbd2_journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
-{
- if (buffer_mapped(bh))
- return ext4_journal_dirty_data(handle, bh);
- return 0;
-}
-
/*
- * Note that we always start a transaction even if we're not journalling
- * data. This is to preserve ordering: any hole instantiation within
- * __block_write_full_page -> ext4_get_block() should be journalled
- * along with the data so we don't crash and then get metadata which
- * refers to old data.
+ * Note that we don't need to start a transaction unless we're journaling data
+ * because we should have holes filled from ext4_page_mkwrite(). We even don't
+ * need to file the inode to the transaction's list in ordered mode because if
+ * we are writing back data added by write(), the inode is already there and if
+ * we are writing back data modified via mmap(), noone guarantees in which
+ * transaction the data will hit the disk. In case we are journaling data, we
+ * cannot start transaction directly because transaction start ranks above page
+ * lock so we have to do some magic.
*
- * In all journalling modes block_write_full_page() will start the I/O.
+ * In all journaling modes block_write_full_page() will start the I/O.
*
* Problem:
*
* disastrous. Any write() or metadata operation will sync the fs for
* us.
*
- * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
- * we don't need to open a transaction here.
*/
-static int ext4_ordered_writepage(struct page *page,
+static int __ext4_normal_writepage(struct page *page,
struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
- struct buffer_head *page_bufs;
- handle_t *handle = NULL;
- int ret = 0;
- int err;
-
- J_ASSERT(PageLocked(page));
-
- /*
- * We give up here if we're reentered, because it might be for a
- * different filesystem.
- */
- if (ext4_journal_current_handle())
- goto out_fail;
-
- handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
- goto out_fail;
- }
+ if (test_opt(inode->i_sb, NOBH))
+ return nobh_writepage(page, ext4_get_block, wbc);
+ else
+ return block_write_full_page(page, ext4_get_block, wbc);
+}
- if (!page_has_buffers(page)) {
- create_empty_buffers(page, inode->i_sb->s_blocksize,
- (1 << BH_Dirty)|(1 << BH_Uptodate));
- }
- page_bufs = page_buffers(page);
- walk_page_buffers(handle, page_bufs, 0,
- PAGE_CACHE_SIZE, NULL, bget_one);
- ret = block_write_full_page(page, ext4_get_block, wbc);
+static int ext4_normal_writepage(struct page *page,
+ struct writeback_control *wbc)
+{
+ struct inode *inode = page->mapping->host;
+ loff_t size = i_size_read(inode);
+ loff_t len;
- /*
- * The page can become unlocked at any point now, and
- * truncate can then come in and change things. So we
- * can't touch *page from now on. But *page_bufs is
- * safe due to elevated refcount.
- */
+ J_ASSERT(PageLocked(page));
+ J_ASSERT(page_has_buffers(page));
+ if (page->index == size >> PAGE_CACHE_SHIFT)
+ len = size & ~PAGE_CACHE_MASK;
+ else
+ len = PAGE_CACHE_SIZE;
+ BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
+ ext4_bh_unmapped_or_delay));
- /*
- * And attach them to the current transaction. But only if
- * block_write_full_page() succeeded. Otherwise they are unmapped,
- * and generally junk.
- */
- if (ret == 0) {
- err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
- NULL, jbd2_journal_dirty_data_fn);
- if (!ret)
- ret = err;
- }
- walk_page_buffers(handle, page_bufs, 0,
- PAGE_CACHE_SIZE, NULL, bput_one);
- err = ext4_journal_stop(handle);
- if (!ret)
- ret = err;
- return ret;
+ if (!ext4_journal_current_handle())
+ return __ext4_normal_writepage(page, wbc);
-out_fail:
redirty_page_for_writepage(wbc, page);
unlock_page(page);
- return ret;
+ return 0;
}
-static int ext4_writeback_writepage(struct page *page,
+static int __ext4_journalled_writepage(struct page *page,
struct writeback_control *wbc)
{
- struct inode *inode = page->mapping->host;
+ struct address_space *mapping = page->mapping;
+ struct inode *inode = mapping->host;
+ struct buffer_head *page_bufs;
handle_t *handle = NULL;
int ret = 0;
int err;
- if (ext4_journal_current_handle())
- goto out_fail;
+ ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE, ext4_get_block);
+ if (ret != 0)
+ goto out_unlock;
+
+ page_bufs = page_buffers(page);
+ walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, NULL,
+ bget_one);
+ /* As soon as we unlock the page, it can go away, but we have
+ * references to buffers so we are safe */
+ unlock_page(page);
handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
- goto out_fail;
+ goto out;
}
- if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
- ret = nobh_writepage(page, ext4_get_block, wbc);
- else
- ret = block_write_full_page(page, ext4_get_block, wbc);
+ ret = walk_page_buffers(handle, page_bufs, 0,
+ PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
+ err = walk_page_buffers(handle, page_bufs, 0,
+ PAGE_CACHE_SIZE, NULL, write_end_fn);
+ if (ret == 0)
+ ret = err;
err = ext4_journal_stop(handle);
if (!ret)
ret = err;
- return ret;
-out_fail:
- redirty_page_for_writepage(wbc, page);
+ walk_page_buffers(handle, page_bufs, 0,
+ PAGE_CACHE_SIZE, NULL, bput_one);
+ EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
+ goto out;
+
+out_unlock:
unlock_page(page);
+out:
return ret;
}
struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
- handle_t *handle = NULL;
- int ret = 0;
- int err;
+ loff_t size = i_size_read(inode);
+ loff_t len;
- if (ext4_journal_current_handle())
- goto no_write;
+ J_ASSERT(PageLocked(page));
+ J_ASSERT(page_has_buffers(page));
+ if (page->index == size >> PAGE_CACHE_SHIFT)
+ len = size & ~PAGE_CACHE_MASK;
+ else
+ len = PAGE_CACHE_SIZE;
+ BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
+ ext4_bh_unmapped_or_delay));
- handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
+ if (ext4_journal_current_handle())
goto no_write;
- }
- if (!page_has_buffers(page) || PageChecked(page)) {
+ if (PageChecked(page)) {
/*
* It's mmapped pagecache. Add buffers and journal it. There
* doesn't seem much point in redirtying the page here.
*/
ClearPageChecked(page);
- ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
- ext4_get_block);
- if (ret != 0) {
- ext4_journal_stop(handle);
- goto out_unlock;
- }
- ret = walk_page_buffers(handle, page_buffers(page), 0,
- PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
-
- err = walk_page_buffers(handle, page_buffers(page), 0,
- PAGE_CACHE_SIZE, NULL, write_end_fn);
- if (ret == 0)
- ret = err;
- EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
- unlock_page(page);
+ return __ext4_journalled_writepage(page, wbc);
} else {
/*
* It may be a page full of checkpoint-mode buffers. We don't
* really know unless we go poke around in the buffer_heads.
* But block_write_full_page will do the right thing.
*/
- ret = block_write_full_page(page, ext4_get_block, wbc);
+ return block_write_full_page(page, ext4_get_block, wbc);
}
- err = ext4_journal_stop(handle);
- if (!ret)
- ret = err;
-out:
- return ret;
-
no_write:
redirty_page_for_writepage(wbc, page);
-out_unlock:
unlock_page(page);
- goto out;
+ return 0;
}
static int ext4_readpage(struct file *file, struct page *page)
static const struct address_space_operations ext4_ordered_aops = {
.readpage = ext4_readpage,
.readpages = ext4_readpages,
- .writepage = ext4_ordered_writepage,
+ .writepage = ext4_normal_writepage,
.sync_page = block_sync_page,
.write_begin = ext4_write_begin,
.write_end = ext4_ordered_write_end,
static const struct address_space_operations ext4_writeback_aops = {
.readpage = ext4_readpage,
.readpages = ext4_readpages,
- .writepage = ext4_writeback_writepage,
+ .writepage = ext4_normal_writepage,
.sync_page = block_sync_page,
.write_begin = ext4_write_begin,
.write_end = ext4_writeback_write_end,
.releasepage = ext4_releasepage,
};
+static const struct address_space_operations ext4_da_aops = {
+ .readpage = ext4_readpage,
+ .readpages = ext4_readpages,
+ .writepage = ext4_da_writepage,
+ .writepages = ext4_da_writepages,
+ .sync_page = block_sync_page,
+ .write_begin = ext4_da_write_begin,
+ .write_end = ext4_da_write_end,
+ .bmap = ext4_bmap,
+ .invalidatepage = ext4_da_invalidatepage,
+ .releasepage = ext4_releasepage,
+ .direct_IO = ext4_direct_IO,
+ .migratepage = buffer_migrate_page,
+};
+
void ext4_set_aops(struct inode *inode)
{
if (ext4_should_order_data(inode))
inode->i_mapping->a_ops = &ext4_ordered_aops;
+ else if (ext4_should_writeback_data(inode) &&
+ test_opt(inode->i_sb, DELALLOC))
+ inode->i_mapping->a_ops = &ext4_da_aops;
else if (ext4_should_writeback_data(inode))
inode->i_mapping->a_ops = &ext4_writeback_aops;
else
* This required during truncate. We need to physically zero the tail end
* of that block so it doesn't yield old data if the file is later grown.
*/
-int ext4_block_truncate_page(handle_t *handle, struct page *page,
+int ext4_block_truncate_page(handle_t *handle,
struct address_space *mapping, loff_t from)
{
ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
ext4_lblk_t iblock;
struct inode *inode = mapping->host;
struct buffer_head *bh;
+ struct page *page;
int err = 0;
+ page = grab_cache_page(mapping, from >> PAGE_CACHE_SHIFT);
+ if (!page)
+ return -EINVAL;
+
blocksize = inode->i_sb->s_blocksize;
length = blocksize - (offset & (blocksize - 1));
iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
err = ext4_journal_dirty_metadata(handle, bh);
} else {
if (ext4_should_order_data(inode))
- err = ext4_journal_dirty_data(handle, bh);
+ err = ext4_jbd2_file_inode(handle, inode);
mark_buffer_dirty(bh);
}
if (this_bh) {
BUFFER_TRACE(this_bh, "call ext4_journal_dirty_metadata");
- ext4_journal_dirty_metadata(handle, this_bh);
+
+ /*
+ * The buffer head should have an attached journal head at this
+ * point. However, if the data is corrupted and an indirect
+ * block pointed to itself, it would have been detached when
+ * the block was cleared. Check for this instead of OOPSing.
+ */
+ if (bh2jh(this_bh))
+ ext4_journal_dirty_metadata(handle, this_bh);
+ else
+ ext4_error(inode->i_sb, __func__,
+ "circular indirect block detected, "
+ "inode=%lu, block=%llu",
+ inode->i_ino,
+ (unsigned long long) this_bh->b_blocknr);
}
}
}
}
+int ext4_can_truncate(struct inode *inode)
+{
+ if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+ return 0;
+ if (S_ISREG(inode->i_mode))
+ return 1;
+ if (S_ISDIR(inode->i_mode))
+ return 1;
+ if (S_ISLNK(inode->i_mode))
+ return !ext4_inode_is_fast_symlink(inode);
+ return 0;
+}
+
/*
* ext4_truncate()
*
int n;
ext4_lblk_t last_block;
unsigned blocksize = inode->i_sb->s_blocksize;
- struct page *page;
- if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
- S_ISLNK(inode->i_mode)))
- return;
- if (ext4_inode_is_fast_symlink(inode))
- return;
- if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+ if (!ext4_can_truncate(inode))
return;
- /*
- * We have to lock the EOF page here, because lock_page() nests
- * outside jbd2_journal_start().
- */
- if ((inode->i_size & (blocksize - 1)) == 0) {
- /* Block boundary? Nothing to do */
- page = NULL;
- } else {
- page = grab_cache_page(mapping,
- inode->i_size >> PAGE_CACHE_SHIFT);
- if (!page)
- return;
- }
-
if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
- ext4_ext_truncate(inode, page);
+ ext4_ext_truncate(inode);
return;
}
handle = start_transaction(inode);
- if (IS_ERR(handle)) {
- if (page) {
- clear_highpage(page);
- flush_dcache_page(page);
- unlock_page(page);
- page_cache_release(page);
- }
+ if (IS_ERR(handle))
return; /* AKPM: return what? */
- }
last_block = (inode->i_size + blocksize-1)
>> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
- if (page)
- ext4_block_truncate_page(handle, page, mapping, inode->i_size);
+ if (inode->i_size & (blocksize - 1))
+ if (ext4_block_truncate_page(handle, mapping, inode->i_size))
+ goto out_stop;
n = ext4_block_to_path(inode, last_block, offsets, NULL);
if (n == 0)
* be freed, so we have a strong guarantee that no future commit will
* leave these blocks visible to the user.)
*
- * Called with inode->sem down.
+ * Another thing we have to assure is that if we are in ordered mode
+ * and inode is still attached to the committing transaction, we must
+ * we start writeout of all the dirty pages which are being truncated.
+ * This way we are sure that all the data written in the previous
+ * transaction are already on disk (truncate waits for pages under
+ * writeback).
+ *
+ * Called with inode->i_mutex down.
*/
int ext4_setattr(struct dentry *dentry, struct iattr *attr)
{
if (!error)
error = rc;
ext4_journal_stop(handle);
+
+ if (ext4_should_order_data(inode)) {
+ error = ext4_begin_ordered_truncate(inode,
+ attr->ia_size);
+ if (error) {
+ /* Do as much error cleanup as possible */
+ handle = ext4_journal_start(inode, 3);
+ if (IS_ERR(handle)) {
+ ext4_orphan_del(NULL, inode);
+ goto err_out;
+ }
+ ext4_orphan_del(handle, inode);
+ ext4_journal_stop(handle);
+ goto err_out;
+ }
+ }
}
rc = inode_setattr(inode, attr);
return err;
}
+
+static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
+{
+ return !buffer_mapped(bh);
+}
+
+int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page)
+{
+ loff_t size;
+ unsigned long len;
+ int ret = -EINVAL;
+ struct file *file = vma->vm_file;
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct address_space *mapping = inode->i_mapping;
+
+ /*
+ * Get i_alloc_sem to stop truncates messing with the inode. We cannot
+ * get i_mutex because we are already holding mmap_sem.
+ */
+ down_read(&inode->i_alloc_sem);
+ size = i_size_read(inode);
+ if (page->mapping != mapping || size <= page_offset(page)
+ || !PageUptodate(page)) {
+ /* page got truncated from under us? */
+ goto out_unlock;
+ }
+ ret = 0;
+ if (PageMappedToDisk(page))
+ goto out_unlock;
+
+ if (page->index == size >> PAGE_CACHE_SHIFT)
+ len = size & ~PAGE_CACHE_MASK;
+ else
+ len = PAGE_CACHE_SIZE;
+
+ if (page_has_buffers(page)) {
+ /* return if we have all the buffers mapped */
+ if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
+ ext4_bh_unmapped))
+ goto out_unlock;
+ }
+ /*
+ * OK, we need to fill the hole... Do write_begin write_end
+ * to do block allocation/reservation.We are not holding
+ * inode.i__mutex here. That allow * parallel write_begin,
+ * write_end call. lock_page prevent this from happening
+ * on the same page though
+ */
+ ret = mapping->a_ops->write_begin(file, mapping, page_offset(page),
+ len, AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+ if (ret < 0)
+ goto out_unlock;
+ ret = mapping->a_ops->write_end(file, mapping, page_offset(page),
+ len, len, page, NULL);
+ if (ret < 0)
+ goto out_unlock;
+ ret = 0;
+out_unlock:
+ up_read(&inode->i_alloc_sem);
+ return ret;
+}
projects / mirror_ubuntu-bionic-kernel.git / blobdiff