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ext4: remove vestiges of nobh support 

The nobh option was only supported for writeback mode, but given that all
write paths actually create buffer heads it effectively was a no-op already.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Christoph Hellwig 2010-06-14 14:42:49 -04:00 committed by Theodore Ts'o
parent 5a0790c2c4
commit 206f7ab4f4
4 changed files with 15 additions and 44 deletions
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1
fs/ext4/ext4.h
View File

@ -873,7 +873,6 @@ struct ext4_inode_info {
#define EXT4_MOUNT_POSIX_ACL 0x08000 /* POSIX Access Control Lists */
#define EXT4_MOUNT_NO_AUTO_DA_ALLOC 0x10000 /* No auto delalloc mapping */
#define EXT4_MOUNT_BARRIER 0x20000 /* Use block barriers */
#define EXT4_MOUNT_NOBH 0x40000 /* No bufferheads */
#define EXT4_MOUNT_QUOTA 0x80000 /* Some quota option set */
#define EXT4_MOUNT_USRQUOTA 0x100000 /* "old" user quota */
#define EXT4_MOUNT_GRPQUOTA 0x200000 /* "old" group quota */

10
fs/ext4/ext4_jbd2.h
View File

@ -313,17 +313,15 @@ static inline int ext4_should_writeback_data(struct inode *inode)
* This function controls whether or not we should try to go down the
* dioread_nolock code paths, which makes it safe to avoid taking
* i_mutex for direct I/O reads. This only works for extent-based
* files, and it doesn't work for nobh or if data journaling is
* enabled, since the dioread_nolock code uses b_private to pass
* information back to the I/O completion handler, and this conflicts
* with the jbd's use of b_private.
* files, and it doesn't work if data journaling is enabled, since the
* dioread_nolock code uses b_private to pass information back to the
* I/O completion handler, and this conflicts with the jbd's use of
* b_private.
*/
static inline int ext4_should_dioread_nolock(struct inode *inode)
{
if (!test_opt(inode->i_sb, DIOREAD_NOLOCK))
return 0;
if (test_opt(inode->i_sb, NOBH))
return 0;
if (!S_ISREG(inode->i_mode))
return 0;
if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))

27
fs/ext4/inode.c
View File

@ -2553,18 +2553,16 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
/*
* This function is used as a standard get_block_t calback function
* when there is no desire to allocate any blocks. It is used as a
* callback function for block_prepare_write(), nobh_writepage(), and
* block_write_full_page(). These functions should only try to map a
* single block at a time.
* callback function for block_prepare_write() and block_write_full_page().
* These functions should only try to map a single block at a time.
*
* Since this function doesn't do block allocations even if the caller
* requests it by passing in create=1, it is critically important that
* any caller checks to make sure that any buffer heads are returned
* by this function are either all already mapped or marked for
* delayed allocation before calling nobh_writepage() or
* block_write_full_page(). Otherwise, b_blocknr could be left
* unitialized, and the page write functions will be taken by
* surprise.
* delayed allocation before calling block_write_full_page(). Otherwise,
* b_blocknr could be left unitialized, and the page write functions will
* be taken by surprise.
*/
static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
@ -2749,9 +2747,7 @@ static int ext4_writepage(struct page *page,
return __ext4_journalled_writepage(page, len);
}
if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
ret = nobh_writepage(page, noalloc_get_block_write, wbc);
else if (page_bufs && buffer_uninit(page_bufs)) {
if (page_bufs && buffer_uninit(page_bufs)) {
ext4_set_bh_endio(page_bufs, inode);
ret = block_write_full_page_endio(page, noalloc_get_block_write,
wbc, ext4_end_io_buffer_write);
@ -4125,17 +4121,6 @@ int ext4_block_truncate_page(handle_t *handle,
length = blocksize - (offset & (blocksize - 1));
iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
/*
* For "nobh" option, we can only work if we don't need to
* read-in the page - otherwise we create buffers to do the IO.
*/
if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
ext4_should_writeback_data(inode) && PageUptodate(page)) {
zero_user(page, offset, length);
set_page_dirty(page);
goto unlock;
}
if (!page_has_buffers(page))
create_empty_buffers(page, blocksize, 0);

21
fs/ext4/super.c
View File

@ -946,8 +946,6 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
seq_puts(seq, ",journal_async_commit");
else if (test_opt(sb, JOURNAL_CHECKSUM))
seq_puts(seq, ",journal_checksum");
if (test_opt(sb, NOBH))
seq_puts(seq, ",nobh");
if (test_opt(sb, I_VERSION))
seq_puts(seq, ",i_version");
if (!test_opt(sb, DELALLOC))
@ -1624,10 +1622,12 @@ set_qf_format:
*n_blocks_count = option;
break;
case Opt_nobh:
set_opt(sbi->s_mount_opt, NOBH);
ext4_msg(sb, KERN_WARNING,
"Ignoring deprecated nobh option");
break;
case Opt_bh:
clear_opt(sbi->s_mount_opt, NOBH);
ext4_msg(sb, KERN_WARNING,
"Ignoring deprecated bh option");
break;
case Opt_i_version:
set_opt(sbi->s_mount_opt, I_VERSION);
@ -2912,18 +2912,7 @@ no_journal:
ext4_msg(sb, KERN_ERR, "insufficient memory");
goto failed_mount_wq;
}
if (test_opt(sb, NOBH)) {
if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
ext4_msg(sb, KERN_WARNING, "Ignoring nobh option - "
"its supported only with writeback mode");
clear_opt(sbi->s_mount_opt, NOBH);
}
if (test_opt(sb, DIOREAD_NOLOCK)) {
ext4_msg(sb, KERN_WARNING, "dioread_nolock option is "
"not supported with nobh mode");
goto failed_mount_wq;
}
}
EXT4_SB(sb)->dio_unwritten_wq = create_workqueue("ext4-dio-unwritten");
if (!EXT4_SB(sb)->dio_unwritten_wq) {
printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");