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Date: Thu, 18 Dec 2014 19:59:05 +0400
From: Dmitry Monakhov <dmonakhov@...nvz.org>
To: linux-ext4@...r.kernel.org
Cc: tytso@....edu, Dmitry Monakhov <dmonakhov@...nvz.org>
Subject: [PATCH 1/2] ext4: fix seek_data cleanup
- Remove usless condition page_has_buffers(). We already checked that previously.
- The goal of ext4_find_unwritten_pgoff() is to distinguish uninitialized data
from initialized or delayed ones so check (buffer_uptodate() || buffer_unwritten() is
not correct. Data is delayed if bh_uptodate && (bh_delayed || bh_async_write)
- Rename ext4_find_unwritten_pgoff -> ext4_find_delayed_pgoff
- Fix seek_data/seek_hole for case blk_sz != pg_sz.
tested on following configurations
xfstest-blk conf: ext3, ext3-1k, ext3-1k-da, 1k, 4k
test: generic/285
Signed-off-by: Dmitry Monakhov <dmonakhov@...nvz.org>
---
fs/ext4/file.c | 58 ++++++++++++++++++++++++++++---------------------------
1 files changed, 30 insertions(+), 28 deletions(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 513c12c..8ec48a4 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -273,19 +273,19 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
* we determine this extent as a data or a hole according to whether the
* page cache has data or not.
*/
-static int ext4_find_unwritten_pgoff(struct inode *inode, int whence,
- loff_t endoff, loff_t *offset)
+static int ext4_find_delayed_pgoff(struct inode *inode, int whence,
+ loff_t endoff, loff_t *offset)
{
struct pagevec pvec;
pgoff_t index;
pgoff_t end;
loff_t startoff;
loff_t lastoff;
+ loff_t last_data;
int found = 0;
startoff = *offset;
- lastoff = startoff;
-
+ last_data = lastoff = startoff;
index = startoff >> PAGE_CACHE_SHIFT;
end = endoff >> PAGE_CACHE_SHIFT;
@@ -350,30 +350,32 @@ static int ext4_find_unwritten_pgoff(struct inode *inode, int whence,
unlock_page(page);
continue;
}
-
- if (page_has_buffers(page)) {
- lastoff = page_offset(page);
- bh = head = page_buffers(page);
- do {
- if (buffer_uptodate(bh) ||
- buffer_unwritten(bh)) {
- if (whence == SEEK_DATA)
- found = 1;
- } else {
- if (whence == SEEK_HOLE)
- found = 1;
+ lastoff = page_offset(page);
+ bh = head = page_buffers(page);
+ do {
+ if (buffer_uptodate(bh) &&
+ (buffer_dirty(bh) ||
+ buffer_async_write(bh))) {
+ last_data = lastoff + bh->b_size;
+ if (whence == SEEK_DATA &&
+ lastoff + bh->b_size > startoff)
+ found = 1;
+ } else {
+ if (whence == SEEK_HOLE &&
+ lastoff + bh->b_size > startoff) {
+ lastoff = last_data;
+ found = 1;
}
- if (found) {
- *offset = max_t(loff_t,
+ }
+ if (found) {
+ *offset = max_t(loff_t,
startoff, lastoff);
- unlock_page(page);
- goto out;
- }
- lastoff += bh->b_size;
- bh = bh->b_this_page;
- } while (bh != head);
- }
-
+ unlock_page(page);
+ goto out;
+ }
+ lastoff += bh->b_size;
+ bh = bh->b_this_page;
+ } while (bh != head);
lastoff = page_offset(page) + PAGE_SIZE;
unlock_page(page);
}
@@ -450,7 +452,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
* it will be as a data or a hole according to page
* cache that has data or not.
*/
- if (ext4_find_unwritten_pgoff(inode, SEEK_DATA,
+ if (ext4_find_delayed_pgoff(inode, SEEK_DATA,
next, &offset))
goto out;
@@ -524,7 +526,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
* it will be as a data or a hole according to page
* cache that has data or not.
*/
- if (ext4_find_unwritten_pgoff(inode, SEEK_HOLE,
+ if (ext4_find_delayed_pgoff(inode, SEEK_HOLE,
next, &offset))
goto out;
--
1.7.1
--
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