Messages in this thread | | | From | Daeho Jeong <> | Date | Wed, 20 Mar 2024 10:42:01 -0700 | Subject | Re: [f2fs-dev] [PATCH v3] f2fs: prevent writing without fallocate() for pinned files |
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On Wed, Mar 20, 2024 at 2:38 AM Chao Yu <chao@kernel.org> wrote: > > On 2024/3/20 5:23, Daeho Jeong wrote: > > From: Daeho Jeong <daehojeong@google.com> > > > > In a case writing without fallocate(), we can't guarantee it's allocated > > in the conventional area for zoned stroage. > > > > Signed-off-by: Daeho Jeong <daehojeong@google.com> > > --- > > v2: covered the direct io case > > v3: covered the mkwrite case > > --- > > fs/f2fs/data.c | 14 ++++++++++++-- > > fs/f2fs/file.c | 16 ++++++++-------- > > 2 files changed, 20 insertions(+), 10 deletions(-) > > > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > > index c21b92f18463..d3e5ab2736a6 100644 > > --- a/fs/f2fs/data.c > > +++ b/fs/f2fs/data.c > > @@ -1584,8 +1584,11 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, int flag) > > > > /* use out-place-update for direct IO under LFS mode */ > > if (map->m_may_create && > > - (is_hole || (f2fs_lfs_mode(sbi) && flag == F2FS_GET_BLOCK_DIO))) { > > - if (unlikely(f2fs_cp_error(sbi))) { > > + (is_hole || (f2fs_lfs_mode(sbi) && flag == F2FS_GET_BLOCK_DIO && > > + !f2fs_is_pinned_file(inode)))) { > > + if (unlikely(f2fs_cp_error(sbi)) || > > + (f2fs_is_pinned_file(inode) && is_hole && > > + flag != F2FS_GET_BLOCK_PRE_DIO)) { > > err = -EIO; > > goto sync_out; > > } > > @@ -3378,6 +3381,8 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi, > > f2fs_map_lock(sbi, flag); > > locked = true; > > } else if ((pos & PAGE_MASK) >= i_size_read(inode)) { > > + if (f2fs_is_pinned_file(inode)) > > + return -EIO; > > f2fs_map_lock(sbi, flag); > > locked = true; > > } > > @@ -3407,6 +3412,11 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi, > > > > if (!f2fs_lookup_read_extent_cache_block(inode, index, > > &dn.data_blkaddr)) { > > + if (f2fs_is_pinned_file(inode)) { > > + err = -EIO; > > + goto out; > > + } > > + > > if (locked) { > > err = f2fs_reserve_block(&dn, index); > > goto out; > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > > index 82277e95c88f..4db3b21c804b 100644 > > --- a/fs/f2fs/file.c > > +++ b/fs/f2fs/file.c > > @@ -57,7 +57,7 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) > > struct inode *inode = file_inode(vmf->vma->vm_file); > > struct f2fs_sb_info *sbi = F2FS_I_SB(inode); > > struct dnode_of_data dn; > > - bool need_alloc = true; > > + bool need_alloc = !f2fs_is_pinned_file(inode); > > Will this check races w/ pinfile get|set?
Do you mean "set/clear" case? I believe "set" case is okay, since we can't set if the inode already has a data block. For "clear" case, I believe mkwrite failure is okay in racy conditions caused by clearing the pin flag. What do you think?
> > Thanks, > > > int err = 0; > > vm_fault_t ret; > > > > @@ -114,19 +114,15 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) > > goto out_sem; > > } > > > > + set_new_dnode(&dn, inode, NULL, NULL, 0); > > if (need_alloc) { > > /* block allocation */ > > - set_new_dnode(&dn, inode, NULL, NULL, 0); > > err = f2fs_get_block_locked(&dn, page->index); > > - } > > - > > -#ifdef CONFIG_F2FS_FS_COMPRESSION > > - if (!need_alloc) { > > - set_new_dnode(&dn, inode, NULL, NULL, 0); > > + } else { > > err = f2fs_get_dnode_of_data(&dn, page->index, LOOKUP_NODE); > > f2fs_put_dnode(&dn); > > } > > -#endif > > + > > if (err) { > > unlock_page(page); > > goto out_sem; > > @@ -4611,6 +4607,10 @@ static int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *iter, > > return ret; > > } > > > > + /* For pinned files, it should be fallocate()-ed in advance. */ > > + if (f2fs_is_pinned_file(inode)) > > + return 0; > > + > > /* Do not preallocate blocks that will be written partially in 4KB. */ > > map.m_lblk = F2FS_BLK_ALIGN(pos); > > map.m_len = F2FS_BYTES_TO_BLK(pos + count);
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