fs: restore nobh
Implement nobh in new aops. This is a bit tricky. FWIW, nobh_truncate is now implemented in a way that does not create blocks in sparse regions, which is a silly thing for it to have been doing (isn't it?) ext2 survives fsx and fsstress. jfs is converted as well... ext3 should be easy to do (but not done yet). [akpm@linux-foundation.org: coding-style fixes] Cc: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>hifive-unleashed-5.1
Nick Piggin
Linus Torvalds
parent
b6af1bcd87
commit
03158cd7eb
229
fs/buffer.c
229
fs/buffer.c
|
|
@ -2369,7 +2369,7 @@ out_unlock:
|
|||
}
|
||||
|
||||
/*
|
||||
* nobh_prepare_write()'s prereads are special: the buffer_heads are freed
|
||||
* nobh_write_begin()'s prereads are special: the buffer_heads are freed
|
||||
* immediately, while under the page lock. So it needs a special end_io
|
||||
* handler which does not touch the bh after unlocking it.
|
||||
*/
|
||||
|
|
@ -2378,17 +2378,46 @@ static void end_buffer_read_nobh(struct buffer_head *bh, int uptodate)
|
|||
__end_buffer_read_notouch(bh, uptodate);
|
||||
}
|
||||
|
||||
/*
|
||||
* Attach the singly-linked list of buffers created by nobh_write_begin, to
|
||||
* the page (converting it to circular linked list and taking care of page
|
||||
* dirty races).
|
||||
*/
|
||||
static void attach_nobh_buffers(struct page *page, struct buffer_head *head)
|
||||
{
|
||||
struct buffer_head *bh;
|
||||
|
||||
BUG_ON(!PageLocked(page));
|
||||
|
||||
spin_lock(&page->mapping->private_lock);
|
||||
bh = head;
|
||||
do {
|
||||
if (PageDirty(page))
|
||||
set_buffer_dirty(bh);
|
||||
if (!bh->b_this_page)
|
||||
bh->b_this_page = head;
|
||||
bh = bh->b_this_page;
|
||||
} while (bh != head);
|
||||
attach_page_buffers(page, head);
|
||||
spin_unlock(&page->mapping->private_lock);
|
||||
}
|
||||
|
||||
/*
|
||||
* On entry, the page is fully not uptodate.
|
||||
* On exit the page is fully uptodate in the areas outside (from,to)
|
||||
*/
|
||||
int nobh_prepare_write(struct page *page, unsigned from, unsigned to,
|
||||
int nobh_write_begin(struct file *file, struct address_space *mapping,
|
||||
loff_t pos, unsigned len, unsigned flags,
|
||||
struct page **pagep, void **fsdata,
|
||||
get_block_t *get_block)
|
||||
{
|
||||
struct inode *inode = page->mapping->host;
|
||||
struct inode *inode = mapping->host;
|
||||
const unsigned blkbits = inode->i_blkbits;
|
||||
const unsigned blocksize = 1 << blkbits;
|
||||
struct buffer_head *head, *bh;
|
||||
struct page *page;
|
||||
pgoff_t index;
|
||||
unsigned from, to;
|
||||
unsigned block_in_page;
|
||||
unsigned block_start, block_end;
|
||||
sector_t block_in_file;
|
||||
|
|
@ -2397,8 +2426,23 @@ int nobh_prepare_write(struct page *page, unsigned from, unsigned to,
|
|||
int ret = 0;
|
||||
int is_mapped_to_disk = 1;
|
||||
|
||||
if (page_has_buffers(page))
|
||||
return block_prepare_write(page, from, to, get_block);
|
||||
index = pos >> PAGE_CACHE_SHIFT;
|
||||
from = pos & (PAGE_CACHE_SIZE - 1);
|
||||
to = from + len;
|
||||
|
||||
page = __grab_cache_page(mapping, index);
|
||||
if (!page)
|
||||
return -ENOMEM;
|
||||
*pagep = page;
|
||||
*fsdata = NULL;
|
||||
|
||||
if (page_has_buffers(page)) {
|
||||
unlock_page(page);
|
||||
page_cache_release(page);
|
||||
*pagep = NULL;
|
||||
return block_write_begin(file, mapping, pos, len, flags, pagep,
|
||||
fsdata, get_block);
|
||||
}
|
||||
|
||||
if (PageMappedToDisk(page))
|
||||
return 0;
|
||||
|
|
@ -2413,8 +2457,10 @@ int nobh_prepare_write(struct page *page, unsigned from, unsigned to,
|
|||
* than the circular one we're used to.
|
||||
*/
|
||||
head = alloc_page_buffers(page, blocksize, 0);
|
||||
if (!head)
|
||||
return -ENOMEM;
|
||||
if (!head) {
|
||||
ret = -ENOMEM;
|
||||
goto out_release;
|
||||
}
|
||||
|
||||
block_in_file = (sector_t)page->index << (PAGE_CACHE_SHIFT - blkbits);
|
||||
|
||||
|
|
@ -2483,15 +2529,12 @@ int nobh_prepare_write(struct page *page, unsigned from, unsigned to,
|
|||
if (is_mapped_to_disk)
|
||||
SetPageMappedToDisk(page);
|
||||
|
||||
do {
|
||||
bh = head;
|
||||
head = head->b_this_page;
|
||||
free_buffer_head(bh);
|
||||
} while (head);
|
||||
*fsdata = head; /* to be released by nobh_write_end */
|
||||
|
||||
return 0;
|
||||
|
||||
failed:
|
||||
BUG_ON(!ret);
|
||||
/*
|
||||
* Error recovery is a bit difficult. We need to zero out blocks that
|
||||
* were newly allocated, and dirty them to ensure they get written out.
|
||||
|
|
@ -2499,64 +2542,57 @@ failed:
|
|||
* the handling of potential IO errors during writeout would be hard
|
||||
* (could try doing synchronous writeout, but what if that fails too?)
|
||||
*/
|
||||
spin_lock(&page->mapping->private_lock);
|
||||
bh = head;
|
||||
block_start = 0;
|
||||
do {
|
||||
if (PageUptodate(page))
|
||||
set_buffer_uptodate(bh);
|
||||
if (PageDirty(page))
|
||||
set_buffer_dirty(bh);
|
||||
attach_nobh_buffers(page, head);
|
||||
page_zero_new_buffers(page, from, to);
|
||||
|
||||
block_end = block_start+blocksize;
|
||||
if (block_end <= from)
|
||||
goto next;
|
||||
if (block_start >= to)
|
||||
goto next;
|
||||
out_release:
|
||||
unlock_page(page);
|
||||
page_cache_release(page);
|
||||
*pagep = NULL;
|
||||
|
||||
if (buffer_new(bh)) {
|
||||
clear_buffer_new(bh);
|
||||
if (!buffer_uptodate(bh)) {
|
||||
zero_user_page(page, block_start, bh->b_size, KM_USER0);
|
||||
set_buffer_uptodate(bh);
|
||||
}
|
||||
mark_buffer_dirty(bh);
|
||||
}
|
||||
next:
|
||||
block_start = block_end;
|
||||
if (!bh->b_this_page)
|
||||
bh->b_this_page = head;
|
||||
bh = bh->b_this_page;
|
||||
} while (bh != head);
|
||||
attach_page_buffers(page, head);
|
||||
spin_unlock(&page->mapping->private_lock);
|
||||
if (pos + len > inode->i_size)
|
||||
vmtruncate(inode, inode->i_size);
|
||||
|
||||
return ret;
|
||||
}
|
||||
EXPORT_SYMBOL(nobh_prepare_write);
|
||||
EXPORT_SYMBOL(nobh_write_begin);
|
||||
|
||||
/*
|
||||
* Make sure any changes to nobh_commit_write() are reflected in
|
||||
* nobh_truncate_page(), since it doesn't call commit_write().
|
||||
*/
|
||||
int nobh_commit_write(struct file *file, struct page *page,
|
||||
unsigned from, unsigned to)
|
||||
int nobh_write_end(struct file *file, struct address_space *mapping,
|
||||
loff_t pos, unsigned len, unsigned copied,
|
||||
struct page *page, void *fsdata)
|
||||
{
|
||||
struct inode *inode = page->mapping->host;
|
||||
loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
|
||||
struct buffer_head *head = NULL;
|
||||
struct buffer_head *bh;
|
||||
|
||||
if (page_has_buffers(page))
|
||||
return generic_commit_write(file, page, from, to);
|
||||
if (!PageMappedToDisk(page)) {
|
||||
if (unlikely(copied < len) && !page_has_buffers(page))
|
||||
attach_nobh_buffers(page, head);
|
||||
if (page_has_buffers(page))
|
||||
return generic_write_end(file, mapping, pos, len,
|
||||
copied, page, fsdata);
|
||||
}
|
||||
|
||||
SetPageUptodate(page);
|
||||
set_page_dirty(page);
|
||||
if (pos > inode->i_size) {
|
||||
i_size_write(inode, pos);
|
||||
if (pos+copied > inode->i_size) {
|
||||
i_size_write(inode, pos+copied);
|
||||
mark_inode_dirty(inode);
|
||||
}
|
||||
return 0;
|
||||
|
||||
unlock_page(page);
|
||||
page_cache_release(page);
|
||||
|
||||
head = fsdata;
|
||||
while (head) {
|
||||
bh = head;
|
||||
head = head->b_this_page;
|
||||
free_buffer_head(bh);
|
||||
}
|
||||
|
||||
return copied;
|
||||
}
|
||||
EXPORT_SYMBOL(nobh_commit_write);
|
||||
EXPORT_SYMBOL(nobh_write_end);
|
||||
|
||||
/*
|
||||
* nobh_writepage() - based on block_full_write_page() except
|
||||
|
|
@ -2609,44 +2645,79 @@ out:
|
|||
}
|
||||
EXPORT_SYMBOL(nobh_writepage);
|
||||
|
||||
/*
|
||||
* This function assumes that ->prepare_write() uses nobh_prepare_write().
|
||||
*/
|
||||
int nobh_truncate_page(struct address_space *mapping, loff_t from)
|
||||
int nobh_truncate_page(struct address_space *mapping,
|
||||
loff_t from, get_block_t *get_block)
|
||||
{
|
||||
struct inode *inode = mapping->host;
|
||||
unsigned blocksize = 1 << inode->i_blkbits;
|
||||
pgoff_t index = from >> PAGE_CACHE_SHIFT;
|
||||
unsigned offset = from & (PAGE_CACHE_SIZE-1);
|
||||
unsigned to;
|
||||
unsigned blocksize;
|
||||
sector_t iblock;
|
||||
unsigned length, pos;
|
||||
struct inode *inode = mapping->host;
|
||||
struct page *page;
|
||||
const struct address_space_operations *a_ops = mapping->a_ops;
|
||||
int ret = 0;
|
||||
struct buffer_head map_bh;
|
||||
int err;
|
||||
|
||||
if ((offset & (blocksize - 1)) == 0)
|
||||
goto out;
|
||||
blocksize = 1 << inode->i_blkbits;
|
||||
length = offset & (blocksize - 1);
|
||||
|
||||
/* Block boundary? Nothing to do */
|
||||
if (!length)
|
||||
return 0;
|
||||
|
||||
length = blocksize - length;
|
||||
iblock = (sector_t)index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
|
||||
|
||||
ret = -ENOMEM;
|
||||
page = grab_cache_page(mapping, index);
|
||||
err = -ENOMEM;
|
||||
if (!page)
|
||||
goto out;
|
||||
|
||||
to = (offset + blocksize) & ~(blocksize - 1);
|
||||
ret = a_ops->prepare_write(NULL, page, offset, to);
|
||||
if (ret == 0) {
|
||||
zero_user_page(page, offset, PAGE_CACHE_SIZE - offset,
|
||||
KM_USER0);
|
||||
/*
|
||||
* It would be more correct to call aops->commit_write()
|
||||
* here, but this is more efficient.
|
||||
*/
|
||||
SetPageUptodate(page);
|
||||
set_page_dirty(page);
|
||||
if (page_has_buffers(page)) {
|
||||
has_buffers:
|
||||
unlock_page(page);
|
||||
page_cache_release(page);
|
||||
return block_truncate_page(mapping, from, get_block);
|
||||
}
|
||||
|
||||
/* Find the buffer that contains "offset" */
|
||||
pos = blocksize;
|
||||
while (offset >= pos) {
|
||||
iblock++;
|
||||
pos += blocksize;
|
||||
}
|
||||
|
||||
err = get_block(inode, iblock, &map_bh, 0);
|
||||
if (err)
|
||||
goto unlock;
|
||||
/* unmapped? It's a hole - nothing to do */
|
||||
if (!buffer_mapped(&map_bh))
|
||||
goto unlock;
|
||||
|
||||
/* Ok, it's mapped. Make sure it's up-to-date */
|
||||
if (!PageUptodate(page)) {
|
||||
err = mapping->a_ops->readpage(NULL, page);
|
||||
if (err) {
|
||||
page_cache_release(page);
|
||||
goto out;
|
||||
}
|
||||
lock_page(page);
|
||||
if (!PageUptodate(page)) {
|
||||
err = -EIO;
|
||||
goto unlock;
|
||||
}
|
||||
if (page_has_buffers(page))
|
||||
goto has_buffers;
|
||||
}
|
||||
zero_user_page(page, offset, length, KM_USER0);
|
||||
set_page_dirty(page);
|
||||
err = 0;
|
||||
|
||||
unlock:
|
||||
unlock_page(page);
|
||||
page_cache_release(page);
|
||||
out:
|
||||
return ret;
|
||||
return err;
|
||||
}
|
||||
EXPORT_SYMBOL(nobh_truncate_page);
|
||||
|
||||
|
|
|
|||
|
|
@ -659,6 +659,20 @@ ext2_write_begin(struct file *file, struct address_space *mapping,
|
|||
return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata);
|
||||
}
|
||||
|
||||
static int
|
||||
ext2_nobh_write_begin(struct file *file, struct address_space *mapping,
|
||||
loff_t pos, unsigned len, unsigned flags,
|
||||
struct page **pagep, void **fsdata)
|
||||
{
|
||||
/*
|
||||
* Dir-in-pagecache still uses ext2_write_begin. Would have to rework
|
||||
* directory handling code to pass around offsets rather than struct
|
||||
* pages in order to make this work easily.
|
||||
*/
|
||||
return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
|
||||
ext2_get_block);
|
||||
}
|
||||
|
||||
static int ext2_nobh_writepage(struct page *page,
|
||||
struct writeback_control *wbc)
|
||||
{
|
||||
|
|
@ -710,7 +724,8 @@ const struct address_space_operations ext2_nobh_aops = {
|
|||
.readpages = ext2_readpages,
|
||||
.writepage = ext2_nobh_writepage,
|
||||
.sync_page = block_sync_page,
|
||||
/* XXX: todo */
|
||||
.write_begin = ext2_nobh_write_begin,
|
||||
.write_end = nobh_write_end,
|
||||
.bmap = ext2_bmap,
|
||||
.direct_IO = ext2_direct_IO,
|
||||
.writepages = ext2_writepages,
|
||||
|
|
@ -927,7 +942,8 @@ void ext2_truncate (struct inode * inode)
|
|||
if (mapping_is_xip(inode->i_mapping))
|
||||
xip_truncate_page(inode->i_mapping, inode->i_size);
|
||||
else if (test_opt(inode->i_sb, NOBH))
|
||||
nobh_truncate_page(inode->i_mapping, inode->i_size);
|
||||
nobh_truncate_page(inode->i_mapping,
|
||||
inode->i_size, ext2_get_block);
|
||||
else
|
||||
block_truncate_page(inode->i_mapping,
|
||||
inode->i_size, ext2_get_block);
|
||||
|
|
|
|||
|
|
@ -279,8 +279,7 @@ static int jfs_write_begin(struct file *file, struct address_space *mapping,
|
|||
loff_t pos, unsigned len, unsigned flags,
|
||||
struct page **pagep, void **fsdata)
|
||||
{
|
||||
*pagep = NULL;
|
||||
return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
|
||||
return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
|
||||
jfs_get_block);
|
||||
}
|
||||
|
||||
|
|
@ -306,7 +305,7 @@ const struct address_space_operations jfs_aops = {
|
|||
.writepages = jfs_writepages,
|
||||
.sync_page = block_sync_page,
|
||||
.write_begin = jfs_write_begin,
|
||||
.write_end = generic_write_end,
|
||||
.write_end = nobh_write_end,
|
||||
.bmap = jfs_bmap,
|
||||
.direct_IO = jfs_direct_IO,
|
||||
};
|
||||
|
|
@ -359,7 +358,7 @@ void jfs_truncate(struct inode *ip)
|
|||
{
|
||||
jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
|
||||
|
||||
block_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
|
||||
nobh_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
|
||||
|
||||
IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
|
||||
jfs_truncate_nolock(ip, ip->i_size);
|
||||
|
|
|
|||
|
|
@ -226,9 +226,13 @@ sector_t generic_block_bmap(struct address_space *, sector_t, get_block_t *);
|
|||
int generic_commit_write(struct file *, struct page *, unsigned, unsigned);
|
||||
int block_truncate_page(struct address_space *, loff_t, get_block_t *);
|
||||
int file_fsync(struct file *, struct dentry *, int);
|
||||
int nobh_prepare_write(struct page*, unsigned, unsigned, get_block_t*);
|
||||
int nobh_commit_write(struct file *, struct page *, unsigned, unsigned);
|
||||
int nobh_truncate_page(struct address_space *, loff_t);
|
||||
int nobh_write_begin(struct file *, struct address_space *,
|
||||
loff_t, unsigned, unsigned,
|
||||
struct page **, void **, get_block_t*);
|
||||
int nobh_write_end(struct file *, struct address_space *,
|
||||
loff_t, unsigned, unsigned,
|
||||
struct page *, void *);
|
||||
int nobh_truncate_page(struct address_space *, loff_t, get_block_t *);
|
||||
int nobh_writepage(struct page *page, get_block_t *get_block,
|
||||
struct writeback_control *wbc);
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue