When delayed allocation is disabled (either through mount option or because we are running low on free space), ext4_write_begin() allocates blocks with EXT4_GET_BLOCKS_IO_CREATE_EXT flag. With this flag extent merging is disabled and since ext4_write_begin() is called for each page separately, we end up with a *lot* of 1 block extents in the extent tree and following writeback is writing 1 block at a time which results in very poor write throughput (4 MB/s instead of 200 MB/s). These days when ext4_get_block_unwritten() is used only by ext4_write_begin(), ext4_page_mkwrite() and inline data conversion, we can safely allow extent merging to happen from these paths since following writeback will happen on different boundaries anyway. So use EXT4_GET_BLOCKS_CREATE_UNRIT_EXT instead which restores the performance. Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220520111402.4252-1-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Pull page cache updates from Matthew Wilcox:
- Appoint myself page cache maintainer
- Fix how scsicam uses the page cache
- Use the memalloc_nofs_save() API to replace AOP_FLAG_NOFS
- Remove the AOP flags entirely
- Remove pagecache_write_begin() and pagecache_write_end()
- Documentation updates
- Convert several address_space operations to use folios:
- is_dirty_writeback
- readpage becomes read_folio
- releasepage becomes release_folio
- freepage becomes free_folio
- Change filler_t to require a struct file pointer be the first
argument like ->read_folio
* tag 'folio-5.19' of git://git.infradead.org/users/willy/pagecache: (107 commits)
nilfs2: Fix some kernel-doc comments
Appoint myself page cache maintainer
fs: Remove aops->freepage
secretmem: Convert to free_folio
nfs: Convert to free_folio
orangefs: Convert to free_folio
fs: Add free_folio address space operation
fs: Convert drop_buffers() to use a folio
fs: Change try_to_free_buffers() to take a folio
jbd2: Convert release_buffer_page() to use a folio
jbd2: Convert jbd2_journal_try_to_free_buffers to take a folio
reiserfs: Convert release_buffer_page() to use a folio
fs: Remove last vestiges of releasepage
ubifs: Convert to release_folio
reiserfs: Convert to release_folio
orangefs: Convert to release_folio
ocfs2: Convert to release_folio
nilfs2: Remove comment about releasepage
nfs: Convert to release_folio
jfs: Convert to release_folio
...
Fix following includecheck warning: ./fs/ext4/inode.c: linux/dax.h is included more than once. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Link: https://lore.kernel.org/r/20220504225025.44753-1-yang.lee@linux.alibaba.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Hulk Robot reported a BUG_ON:
==================================================================
EXT4-fs error (device loop3): ext4_mb_generate_buddy:805: group 0,
block bitmap and bg descriptor inconsistent: 25 vs 31513 free clusters
kernel BUG at fs/ext4/ext4_jbd2.c:53!
invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 PID: 25371 Comm: syz-executor.3 Not tainted 5.10.0+ #1
RIP: 0010:ext4_put_nojournal fs/ext4/ext4_jbd2.c:53 [inline]
RIP: 0010:__ext4_journal_stop+0x10e/0x110 fs/ext4/ext4_jbd2.c:116
[...]
Call Trace:
ext4_write_inline_data_end+0x59a/0x730 fs/ext4/inline.c:795
generic_perform_write+0x279/0x3c0 mm/filemap.c:3344
ext4_buffered_write_iter+0x2e3/0x3d0 fs/ext4/file.c:270
ext4_file_write_iter+0x30a/0x11c0 fs/ext4/file.c:520
do_iter_readv_writev+0x339/0x3c0 fs/read_write.c:732
do_iter_write+0x107/0x430 fs/read_write.c:861
vfs_writev fs/read_write.c:934 [inline]
do_pwritev+0x1e5/0x380 fs/read_write.c:1031
[...]
==================================================================
Above issue may happen as follows:
cpu1 cpu2
__________________________|__________________________
do_pwritev
vfs_writev
do_iter_write
ext4_file_write_iter
ext4_buffered_write_iter
generic_perform_write
ext4_da_write_begin
vfs_fallocate
ext4_fallocate
ext4_convert_inline_data
ext4_convert_inline_data_nolock
ext4_destroy_inline_data_nolock
clear EXT4_STATE_MAY_INLINE_DATA
ext4_map_blocks
ext4_ext_map_blocks
ext4_mb_new_blocks
ext4_mb_regular_allocator
ext4_mb_good_group_nolock
ext4_mb_init_group
ext4_mb_init_cache
ext4_mb_generate_buddy --> error
ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)
ext4_restore_inline_data
set EXT4_STATE_MAY_INLINE_DATA
ext4_block_write_begin
ext4_da_write_end
ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)
ext4_write_inline_data_end
handle=NULL
ext4_journal_stop(handle)
__ext4_journal_stop
ext4_put_nojournal(handle)
ref_cnt = (unsigned long)handle
BUG_ON(ref_cnt == 0) ---> BUG_ON
The lock held by ext4_convert_inline_data is xattr_sem, but the lock
held by generic_perform_write is i_rwsem. Therefore, the two locks can
be concurrent.
To solve above issue, we add inode_lock() for ext4_convert_inline_data().
At the same time, move ext4_convert_inline_data() in front of
ext4_punch_hole(), remove similar handling from ext4_punch_hole().
Fixes: 0c8d414f163f ("ext4: let fallocate handle inline data correctly")
Cc: stable@vger.kernel.org
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220428134031.4153381-1-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Symlink's external data block is one kind of metadata block, and now that almost all ext4 metadata block's page cache (e.g. directory blocks, quota blocks...) belongs to bdev backing inode except the symlink. It is essentially worked in data=journal mode like other regular file's data block because probably in order to make it simple for generic VFS code handling symlinks or some other historical reasons, but the logic of creating external data block in ext4_symlink() is complicated. and it also make things confused if user do not want to let the filesystem worked in data=journal mode. This patch convert the final exceptional case and make things clean, move the mapping of the symlink's external data block to bdev like any other metadata block does. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Link: https://lore.kernel.org/r/20220424140936.1898920-3-yi.zhang@huawei.com
Current ext4_getblk() might sleep if some resources are not valid or could be race with a concurrent extents modifing procedure. So we cannot call ext4_getblk() and ext4_map_blocks() to get map blocks in the atomic context in some fast path (e.g. the upcoming procedure of getting symlink external block in the RCU context), even if the map extents have already been check and cached. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Link: https://lore.kernel.org/r/20220424140936.1898920-2-yi.zhang@huawei.com
We got issue as follows:
EXT4-fs error (device loop0) in ext4_reserve_inode_write:5741: Out of memory
EXT4-fs error (device loop0): ext4_setattr:5462: inode #13: comm syz-executor.0: mark_inode_dirty error
EXT4-fs error (device loop0) in ext4_setattr:5519: Out of memory
EXT4-fs error (device loop0): ext4_ind_map_blocks:595: inode #13: comm syz-executor.0: Can't allocate blocks for non-extent mapped inodes with bigalloc
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4361 at fs/ext4/file.c:301 ext4_file_write_iter+0x11c9/0x1220
Modules linked in:
CPU: 1 PID: 4361 Comm: syz-executor.0 Not tainted 5.10.0+ #1
RIP: 0010:ext4_file_write_iter+0x11c9/0x1220
RSP: 0018:ffff924d80b27c00 EFLAGS: 00010282
RAX: ffffffff815a3379 RBX: 0000000000000000 RCX: 000000003b000000
RDX: ffff924d81601000 RSI: 00000000000009cc RDI: 00000000000009cd
RBP: 000000000000000d R08: ffffffffbc5a2c6b R09: 0000902e0e52a96f
R10: ffff902e2b7c1b40 R11: ffff902e2b7c1b40 R12: 000000000000000a
R13: 0000000000000001 R14: ffff902e0e52aa10 R15: ffffffffffffff8b
FS: 00007f81a7f65700(0000) GS:ffff902e3bc80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 000000012db88001 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
do_iter_readv_writev+0x2e5/0x360
do_iter_write+0x112/0x4c0
do_pwritev+0x1e5/0x390
__x64_sys_pwritev2+0x7e/0xa0
do_syscall_64+0x37/0x50
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Above issue may happen as follows:
Assume
inode.i_size=4096
EXT4_I(inode)->i_disksize=4096
step 1: set inode->i_isize = 8192
ext4_setattr
if (attr->ia_size != inode->i_size)
EXT4_I(inode)->i_disksize = attr->ia_size;
rc = ext4_mark_inode_dirty
ext4_reserve_inode_write
ext4_get_inode_loc
__ext4_get_inode_loc
sb_getblk --> return -ENOMEM
...
if (!error) ->will not update i_size
i_size_write(inode, attr->ia_size);
Now:
inode.i_size=4096
EXT4_I(inode)->i_disksize=8192
step 2: Direct write 4096 bytes
ext4_file_write_iter
ext4_dio_write_iter
iomap_dio_rw ->return error
if (extend)
ext4_handle_inode_extension
WARN_ON_ONCE(i_size_read(inode) < EXT4_I(inode)->i_disksize);
->Then trigger warning.
To solve above issue, if mark inode dirty failed in ext4_setattr just
set 'EXT4_I(inode)->i_disksize' with old value.
Signed-off-by: Ye Bin <yebin10@huawei.com>
Link: https://lore.kernel.org/r/20220326065351.761952-1-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
All but two of the callers already have a folio; pass a folio into try_to_free_buffers(). This removes the last user of cancel_dirty_page() so remove that wrapper function too. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jeff Layton <jlayton@kernel.org>
Also convert it to return a bool since it's called from release_folio(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jeff Layton <jlayton@kernel.org>
The use of folios should be pushed deeper into ext4 from here. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jeff Layton <jlayton@kernel.org>