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authorTheodore Ts'o <tytso@mit.edu>2021-09-04 23:46:32 -0400
committerTheodore Ts'o <tytso@mit.edu>2021-09-09 10:47:06 -0400
commit11ef08c9eb52a808b8903004cba0733df6902a43 (patch)
tree7ecde02153887ecd74bbc7e5b916a3a1f48ec90f /fs/ext4
parent1fd95c05d8f742abfe906620780aee4dbe1a2db0 (diff)
parentcc883236b79297f6266ca6f4e7f24f3fd3c736c1 (diff)
Merge branch 'delalloc-buffer-write' into dev
Fix a bug in how we update i_disksize, and the error path in inline_data_end. Finally, drop an unnecessary creation of a journal handle which was only needed for inline data, which can give us a large performance gain in delayed allocation writes. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/ext4.h3
-rw-r--r--fs/ext4/inline.c131
-rw-r--r--fs/ext4/inode.c150
3 files changed, 105 insertions, 179 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 98758e8ea7fc..2fa2dc6f6ac0 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3603,9 +3603,6 @@ extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
unsigned flags,
struct page **pagep,
void **fsdata);
-extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
- unsigned len, unsigned copied,
- struct page *page);
extern int ext4_try_add_inline_entry(handle_t *handle,
struct ext4_filename *fname,
struct inode *dir, struct inode *inode);
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 82bf4ff6be28..50a3031bf466 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -733,45 +733,83 @@ convert:
int ext4_write_inline_data_end(struct inode *inode, loff_t pos, unsigned len,
unsigned copied, struct page *page)
{
- int ret, no_expand;
+ handle_t *handle = ext4_journal_current_handle();
+ int no_expand;
void *kaddr;
struct ext4_iloc iloc;
+ int ret = 0, ret2;
+
+ if (unlikely(copied < len) && !PageUptodate(page))
+ copied = 0;
- if (unlikely(copied < len)) {
- if (!PageUptodate(page)) {
- copied = 0;
+ if (likely(copied)) {
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret) {
+ unlock_page(page);
+ put_page(page);
+ ext4_std_error(inode->i_sb, ret);
goto out;
}
- }
+ ext4_write_lock_xattr(inode, &no_expand);
+ BUG_ON(!ext4_has_inline_data(inode));
- ret = ext4_get_inode_loc(inode, &iloc);
- if (ret) {
- ext4_std_error(inode->i_sb, ret);
- copied = 0;
- goto out;
- }
+ /*
+ * ei->i_inline_off may have changed since
+ * ext4_write_begin() called
+ * ext4_try_to_write_inline_data()
+ */
+ (void) ext4_find_inline_data_nolock(inode);
- ext4_write_lock_xattr(inode, &no_expand);
- BUG_ON(!ext4_has_inline_data(inode));
+ kaddr = kmap_atomic(page);
+ ext4_write_inline_data(inode, &iloc, kaddr, pos, copied);
+ kunmap_atomic(kaddr);
+ SetPageUptodate(page);
+ /* clear page dirty so that writepages wouldn't work for us. */
+ ClearPageDirty(page);
- /*
- * ei->i_inline_off may have changed since ext4_write_begin()
- * called ext4_try_to_write_inline_data()
- */
- (void) ext4_find_inline_data_nolock(inode);
+ ext4_write_unlock_xattr(inode, &no_expand);
+ brelse(iloc.bh);
- kaddr = kmap_atomic(page);
- ext4_write_inline_data(inode, &iloc, kaddr, pos, len);
- kunmap_atomic(kaddr);
- SetPageUptodate(page);
- /* clear page dirty so that writepages wouldn't work for us. */
- ClearPageDirty(page);
+ /*
+ * It's important to update i_size while still holding page
+ * lock: page writeout could otherwise come in and zero
+ * beyond i_size.
+ */
+ ext4_update_inode_size(inode, pos + copied);
+ }
+ unlock_page(page);
+ put_page(page);
- ext4_write_unlock_xattr(inode, &no_expand);
- brelse(iloc.bh);
- mark_inode_dirty(inode);
+ /*
+ * Don't mark the inode dirty under page lock. First, it unnecessarily
+ * makes the holding time of page lock longer. Second, it forces lock
+ * ordering of page lock and transaction start for journaling
+ * filesystems.
+ */
+ if (likely(copied))
+ mark_inode_dirty(inode);
out:
- return copied;
+ /*
+ * If we didn't copy as much data as expected, we need to trim back
+ * size of xattr containing inline data.
+ */
+ if (pos + len > inode->i_size && ext4_can_truncate(inode))
+ ext4_orphan_add(handle, inode);
+
+ ret2 = ext4_journal_stop(handle);
+ if (!ret)
+ ret = ret2;
+ if (pos + len > inode->i_size) {
+ ext4_truncate_failed_write(inode);
+ /*
+ * If truncate failed early the inode might still be
+ * on the orphan list; we need to make sure the inode
+ * is removed from the orphan list in that case.
+ */
+ if (inode->i_nlink)
+ ext4_orphan_del(NULL, inode);
+ }
+ return ret ? ret : copied;
}
struct buffer_head *
@@ -953,43 +991,6 @@ out:
return ret;
}
-int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
- unsigned len, unsigned copied,
- struct page *page)
-{
- int ret;
-
- ret = ext4_write_inline_data_end(inode, pos, len, copied, page);
- if (ret < 0) {
- unlock_page(page);
- put_page(page);
- return ret;
- }
- copied = ret;
-
- /*
- * No need to use i_size_read() here, the i_size
- * cannot change under us because we hold i_mutex.
- *
- * But it's important to update i_size while still holding page lock:
- * page writeout could otherwise come in and zero beyond i_size.
- */
- if (pos+copied > inode->i_size)
- i_size_write(inode, pos+copied);
- unlock_page(page);
- put_page(page);
-
- /*
- * Don't mark the inode dirty under page lock. First, it unnecessarily
- * makes the holding time of page lock longer. Second, it forces lock
- * ordering of page lock and transaction start for journaling
- * filesystems.
- */
- mark_inode_dirty(inode);
-
- return copied;
-}
-
#ifdef INLINE_DIR_DEBUG
void ext4_show_inline_dir(struct inode *dir, struct buffer_head *bh,
void *inline_start, int inline_size)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 62e9165bc69c..8204176256c8 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1284,22 +1284,14 @@ static int ext4_write_end(struct file *file,
loff_t old_size = inode->i_size;
int ret = 0, ret2;
int i_size_changed = 0;
- int inline_data = ext4_has_inline_data(inode);
bool verity = ext4_verity_in_progress(inode);
trace_ext4_write_end(inode, pos, len, copied);
- if (inline_data) {
- ret = ext4_write_inline_data_end(inode, pos, len,
- copied, page);
- if (ret < 0) {
- unlock_page(page);
- put_page(page);
- goto errout;
- }
- copied = ret;
- } else
- copied = block_write_end(file, mapping, pos,
- len, copied, page, fsdata);
+
+ if (ext4_has_inline_data(inode))
+ return ext4_write_inline_data_end(inode, pos, len, copied, page);
+
+ copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
/*
* it's important to update i_size while still holding page lock:
* page writeout could otherwise come in and zero beyond i_size.
@@ -1320,7 +1312,7 @@ static int ext4_write_end(struct file *file,
* ordering of page lock and transaction start for journaling
* filesystems.
*/
- if (i_size_changed || inline_data)
+ if (i_size_changed)
ret = ext4_mark_inode_dirty(handle, inode);
if (pos + len > inode->i_size && !verity && ext4_can_truncate(inode))
@@ -1329,7 +1321,7 @@ static int ext4_write_end(struct file *file,
* inode->i_size. So truncate them
*/
ext4_orphan_add(handle, inode);
-errout:
+
ret2 = ext4_journal_stop(handle);
if (!ret)
ret = ret2;
@@ -1395,7 +1387,6 @@ static int ext4_journalled_write_end(struct file *file,
int partial = 0;
unsigned from, to;
int size_changed = 0;
- int inline_data = ext4_has_inline_data(inode);
bool verity = ext4_verity_in_progress(inode);
trace_ext4_journalled_write_end(inode, pos, len, copied);
@@ -1404,16 +1395,10 @@ static int ext4_journalled_write_end(struct file *file,
BUG_ON(!ext4_handle_valid(handle));
- if (inline_data) {
- ret = ext4_write_inline_data_end(inode, pos, len,
- copied, page);
- if (ret < 0) {
- unlock_page(page);
- put_page(page);
- goto errout;
- }
- copied = ret;
- } else if (unlikely(copied < len) && !PageUptodate(page)) {
+ if (ext4_has_inline_data(inode))
+ return ext4_write_inline_data_end(inode, pos, len, copied, page);
+
+ if (unlikely(copied < len) && !PageUptodate(page)) {
copied = 0;
ext4_journalled_zero_new_buffers(handle, inode, page, from, to);
} else {
@@ -1436,7 +1421,7 @@ static int ext4_journalled_write_end(struct file *file,
if (old_size < pos && !verity)
pagecache_isize_extended(inode, old_size, pos);
- if (size_changed || inline_data) {
+ if (size_changed) {
ret2 = ext4_mark_inode_dirty(handle, inode);
if (!ret)
ret = ret2;
@@ -1449,7 +1434,6 @@ static int ext4_journalled_write_end(struct file *file,
*/
ext4_orphan_add(handle, inode);
-errout:
ret2 = ext4_journal_stop(handle);
if (!ret)
ret = ret2;
@@ -2932,19 +2916,6 @@ static int ext4_nonda_switch(struct super_block *sb)
return 0;
}
-/* We always reserve for an inode update; the superblock could be there too */
-static int ext4_da_write_credits(struct inode *inode, loff_t pos, unsigned len)
-{
- if (likely(ext4_has_feature_large_file(inode->i_sb)))
- return 1;
-
- if (pos + len <= 0x7fffffffULL)
- return 1;
-
- /* We might need to update the superblock to set LARGE_FILE */
- return 2;
-}
-
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)
@@ -2953,7 +2924,6 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
struct page *page;
pgoff_t index;
struct inode *inode = mapping->host;
- handle_t *handle;
if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
return -EIO;
@@ -2979,41 +2949,11 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
return 0;
}
- /*
- * grab_cache_page_write_begin() can take a long time if the
- * system is thrashing due to memory pressure, or if the page
- * is being written back. So grab it first before we start
- * the transaction handle. This also allows us to allocate
- * the page (if needed) without using GFP_NOFS.
- */
-retry_grab:
+retry:
page = grab_cache_page_write_begin(mapping, index, flags);
if (!page)
return -ENOMEM;
- unlock_page(page);
- /*
- * 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.
- */
-retry_journal:
- handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
- ext4_da_write_credits(inode, pos, len));
- if (IS_ERR(handle)) {
- put_page(page);
- return PTR_ERR(handle);
- }
-
- lock_page(page);
- if (page->mapping != mapping) {
- /* The page got truncated from under us */
- unlock_page(page);
- put_page(page);
- ext4_journal_stop(handle);
- goto retry_grab;
- }
/* In case writeback began while the page was unlocked */
wait_for_stable_page(page);
@@ -3025,20 +2965,18 @@ retry_journal:
#endif
if (ret < 0) {
unlock_page(page);
- ext4_journal_stop(handle);
+ put_page(page);
/*
* block_write_begin may have instantiated a few blocks
* outside i_size. Trim these off again. Don't need
- * i_size_read because we hold i_mutex.
+ * i_size_read because we hold inode lock.
*/
if (pos + len > inode->i_size)
ext4_truncate_failed_write(inode);
if (ret == -ENOSPC &&
ext4_should_retry_alloc(inode->i_sb, &retries))
- goto retry_journal;
-
- put_page(page);
+ goto retry;
return ret;
}
@@ -3075,8 +3013,6 @@ static int ext4_da_write_end(struct file *file,
struct page *page, void *fsdata)
{
struct inode *inode = mapping->host;
- int ret = 0, ret2;
- handle_t *handle = ext4_journal_current_handle();
loff_t new_i_size;
unsigned long start, end;
int write_mode = (int)(unsigned long)fsdata;
@@ -3086,44 +3022,36 @@ static int ext4_da_write_end(struct file *file,
len, copied, page, fsdata);
trace_ext4_da_write_end(inode, pos, len, copied);
+
+ if (write_mode != CONVERT_INLINE_DATA &&
+ ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) &&
+ ext4_has_inline_data(inode))
+ return ext4_write_inline_data_end(inode, pos, len, copied, page);
+
start = pos & (PAGE_SIZE - 1);
end = start + copied - 1;
/*
- * generic_write_end() will run mark_inode_dirty() if i_size
- * changes. So let's piggyback the i_disksize mark_inode_dirty
- * into that.
+ * Since we are holding inode lock, we are sure i_disksize <=
+ * i_size. We also know that if i_disksize < i_size, there are
+ * delalloc writes pending in the range upto i_size. If the end of
+ * the current write is <= i_size, there's no need to touch
+ * i_disksize since writeback will push i_disksize upto i_size
+ * eventually. If the end of the current write is > i_size and
+ * inside an allocated block (ext4_da_should_update_i_disksize()
+ * check), we need to update i_disksize here as neither
+ * ext4_writepage() nor certain ext4_writepages() paths not
+ * allocating blocks update i_disksize.
+ *
+ * Note that we defer inode dirtying to generic_write_end() /
+ * ext4_da_write_inline_data_end().
*/
new_i_size = pos + copied;
- if (copied && new_i_size > EXT4_I(inode)->i_disksize) {
- if (ext4_has_inline_data(inode) ||
- ext4_da_should_update_i_disksize(page, end)) {
- ext4_update_i_disksize(inode, new_i_size);
- /* We need to mark inode dirty even if
- * new_i_size is less that inode->i_size
- * bu greater than i_disksize.(hint delalloc)
- */
- ret = ext4_mark_inode_dirty(handle, inode);
- }
- }
+ if (copied && new_i_size > inode->i_size &&
+ ext4_da_should_update_i_disksize(page, end))
+ ext4_update_i_disksize(inode, new_i_size);
- if (write_mode != CONVERT_INLINE_DATA &&
- ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) &&
- ext4_has_inline_data(inode))
- ret2 = ext4_da_write_inline_data_end(inode, pos, len, copied,
- page);
- else
- ret2 = generic_write_end(file, mapping, pos, len, copied,
- page, fsdata);
-
- copied = ret2;
- if (ret2 < 0)
- ret = ret2;
- ret2 = ext4_journal_stop(handle);
- if (unlikely(ret2 && !ret))
- ret = ret2;
-
- return ret ? ret : copied;
+ return generic_write_end(file, mapping, pos, len, copied, page, fsdata);
}
/*