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ext4: remove EXT4_STATE_DIOREAD_LOCK flag

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Commit 16c5468859 ("ext4: Allow parallel DIO reads") reworked the way
locking happens around parallel dio reads. This resulted in obviating
the need for EXT4_STATE_DIOREAD_LOCK flag and accompanying logic.
Currently this amounts to dead code so let's remove it. No functional
changes

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Nikolay Borisov 2018-03-22 11:52:10 -04:00 committed by Theodore Ts'o
parent fe23cb65c2
commit 1d39834fba
6 changed files with 10 additions and 54 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
fs/ext4/ext4.h
View file

@ -1522,8 +1522,6 @@ enum {
EXT4_STATE_EXT_MIGRATE, /* Inode is migrating */
EXT4_STATE_DIO_UNWRITTEN, /* need convert on dio done*/
EXT4_STATE_NEWENTRY, /* File just added to dir */
EXT4_STATE_DIOREAD_LOCK, /* Disable support for dio read
nolocking */
EXT4_STATE_MAY_INLINE_DATA, /* may have in-inode data */
EXT4_STATE_EXT_PRECACHED, /* extents have been precached */
EXT4_STATE_LUSTRE_EA_INODE, /* Lustre-style ea_inode */
@ -3181,21 +3179,6 @@ static inline void set_bitmap_uptodate(struct buffer_head *bh)
set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
}
/*
* Disable DIO read nolock optimization, so new dioreaders will be forced
* to grab i_mutex
*/
static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
{
ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
smp_mb();
}
static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
{
smp_mb();
ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
}
#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
/* For ioend & aio unwritten conversion wait queues */

19
fs/ext4/extents.c
View file

@ -4796,7 +4796,6 @@ static long ext4_zero_range(struct file *file, loff_t offset,
flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
/* Wait all existing dio workers, newcomers will block on i_mutex */
ext4_inode_block_unlocked_dio(inode);
inode_dio_wait(inode);
/* Preallocate the range including the unaligned edges */
@ -4807,7 +4806,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
round_down(offset, 1 << blkbits)) >> blkbits,
new_size, flags);
if (ret)
goto out_dio;
goto out_mutex;
}
@ -4824,7 +4823,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
ret = ext4_update_disksize_before_punch(inode, offset, len);
if (ret) {
up_write(&EXT4_I(inode)->i_mmap_sem);
goto out_dio;
goto out_mutex;
}
/* Now release the pages and zero block aligned part of pages */
truncate_pagecache_range(inode, start, end - 1);
@ -4834,10 +4833,10 @@ static long ext4_zero_range(struct file *file, loff_t offset,
flags);
up_write(&EXT4_I(inode)->i_mmap_sem);
if (ret)
goto out_dio;
goto out_mutex;
}
if (!partial_begin && !partial_end)
goto out_dio;
goto out_mutex;
/*
* In worst case we have to writeout two nonadjacent unwritten
@ -4850,7 +4849,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
ext4_std_error(inode->i_sb, ret);
goto out_dio;
goto out_mutex;
}
inode->i_mtime = inode->i_ctime = current_time(inode);
@ -4875,8 +4874,6 @@ static long ext4_zero_range(struct file *file, loff_t offset,
ext4_handle_sync(handle);
ext4_journal_stop(handle);
out_dio:
ext4_inode_resume_unlocked_dio(inode);
out_mutex:
inode_unlock(inode);
return ret;
@ -4964,11 +4961,9 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
}
/* Wait all existing dio workers, newcomers will block on i_mutex */
ext4_inode_block_unlocked_dio(inode);
inode_dio_wait(inode);
ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags);
ext4_inode_resume_unlocked_dio(inode);
if (ret)
goto out;
@ -5485,7 +5480,6 @@ int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
}
/* Wait for existing dio to complete */
ext4_inode_block_unlocked_dio(inode);
inode_dio_wait(inode);
/*
@ -5562,7 +5556,6 @@ int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
ext4_journal_stop(handle);
out_mmap:
up_write(&EXT4_I(inode)->i_mmap_sem);
ext4_inode_resume_unlocked_dio(inode);
out_mutex:
inode_unlock(inode);
return ret;
@ -5635,7 +5628,6 @@ int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
}
/* Wait for existing dio to complete */
ext4_inode_block_unlocked_dio(inode);
inode_dio_wait(inode);
/*
@ -5737,7 +5729,6 @@ int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
ext4_journal_stop(handle);
out_mmap:
up_write(&EXT4_I(inode)->i_mmap_sem);
ext4_inode_resume_unlocked_dio(inode);
out_mutex:
inode_unlock(inode);
return ret;

8
fs/ext4/inode.c
View file

@ -4252,7 +4252,6 @@ int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length)
}
/* Wait all existing dio workers, newcomers will block on i_mutex */
ext4_inode_block_unlocked_dio(inode);
inode_dio_wait(inode);
/*
@ -4325,7 +4324,6 @@ int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length)
ext4_journal_stop(handle);
out_dio:
up_write(&EXT4_I(inode)->i_mmap_sem);
ext4_inode_resume_unlocked_dio(inode);
out_mutex:
inode_unlock(inode);
return ret;
@ -5507,9 +5505,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
*/
if (orphan) {
if (!ext4_should_journal_data(inode)) {
ext4_inode_block_unlocked_dio(inode);
inode_dio_wait(inode);
ext4_inode_resume_unlocked_dio(inode);
} else
ext4_wait_for_tail_page_commit(inode);
}
@ -6000,7 +5996,6 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
return -EROFS;
/* Wait for all existing dio workers */
ext4_inode_block_unlocked_dio(inode);
inode_dio_wait(inode);
/*
@ -6016,7 +6011,6 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
err = filemap_write_and_wait(inode->i_mapping);
if (err < 0) {
up_write(&EXT4_I(inode)->i_mmap_sem);
ext4_inode_resume_unlocked_dio(inode);
return err;
}
}
@ -6039,7 +6033,6 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
if (err < 0) {
jbd2_journal_unlock_updates(journal);
percpu_up_write(&sbi->s_journal_flag_rwsem);
ext4_inode_resume_unlocked_dio(inode);
return err;
}
ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
@ -6051,7 +6044,6 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
if (val)
up_write(&EXT4_I(inode)->i_mmap_sem);
ext4_inode_resume_unlocked_dio(inode);
/* Finally we can mark the inode as dirty. */

4
fs/ext4/ioctl.c
View file

@ -124,8 +124,6 @@ static long swap_inode_boot_loader(struct super_block *sb,
truncate_inode_pages(&inode_bl->i_data, 0);
/* Wait for all existing dio workers */
ext4_inode_block_unlocked_dio(inode);
ext4_inode_block_unlocked_dio(inode_bl);
inode_dio_wait(inode);
inode_dio_wait(inode_bl);
@ -186,8 +184,6 @@ static long swap_inode_boot_loader(struct super_block *sb,
ext4_double_up_write_data_sem(inode, inode_bl);
journal_err_out:
ext4_inode_resume_unlocked_dio(inode);
ext4_inode_resume_unlocked_dio(inode_bl);
unlock_two_nondirectories(inode, inode_bl);
iput(inode_bl);
return err;

4
fs/ext4/move_extent.c
View file

@ -601,8 +601,6 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk,
lock_two_nondirectories(orig_inode, donor_inode);
/* Wait for all existing dio workers */
ext4_inode_block_unlocked_dio(orig_inode);
ext4_inode_block_unlocked_dio(donor_inode);
inode_dio_wait(orig_inode);
inode_dio_wait(donor_inode);
@ -693,8 +691,6 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk,
ext4_ext_drop_refs(path);
kfree(path);
ext4_double_up_write_data_sem(orig_inode, donor_inode);
ext4_inode_resume_unlocked_dio(orig_inode);
ext4_inode_resume_unlocked_dio(donor_inode);
unlock_two_nondirectories(orig_inode, donor_inode);
return ret;

12
fs/ext4/super.c
View file

@ -101,15 +101,13 @@ static struct inode *ext4_get_journal_inode(struct super_block *sb,
* i_data_sem (rw)
*
* truncate:
* sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
* i_mmap_rwsem (w) -> page lock
* sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
* transaction start -> i_data_sem (rw)
* sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
* sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
* i_data_sem (rw)
*
* direct IO:
* sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
* sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
* transaction start -> i_data_sem (rw)
* sb_start_write -> i_mutex -> mmap_sem
* sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
*
* writepages:
* transaction start -> page lock(s) -> i_data_sem (rw)