Messages in this thread | | | Date | Thu, 24 Nov 2022 23:12:21 +0800 | Subject | Re: [f2fs-dev] [PATCH v7] f2fs: introduce F2FS_IOC_START_ATOMIC_REPLACE | From | Chao Yu <> |
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On 2022/11/24 5:58, Jaegeuk Kim wrote: > On 11/23, Chao Yu wrote: >> On 2022/11/12 1:04, Daeho Jeong wrote: >>> From: Daeho Jeong <daehojeong@google.com> >>> >>> introduce a new ioctl to replace the whole content of a file atomically, >>> which means it induces truncate and content update at the same time. >>> We can start it with F2FS_IOC_START_ATOMIC_REPLACE and complete it with >>> F2FS_IOC_COMMIT_ATOMIC_WRITE. Or abort it with >>> F2FS_IOC_ABORT_ATOMIC_WRITE. >>> >>> Signed-off-by: Daeho Jeong <daehojeong@google.com> >>> --- >>> v7: changed where to clear FI_ATOMIC_REPLACE >>> fixed tentative race condition in f2fs_ioc_start_atomic_write() >>> v3: move i_size change after setting atomic write flag >>> v2: add undefined ioctl number reported by <lkp@intel.com> >>> --- >>> fs/f2fs/data.c | 3 +++ >>> fs/f2fs/f2fs.h | 1 + >>> fs/f2fs/file.c | 21 +++++++++++++++------ >>> fs/f2fs/segment.c | 13 ++++++++++++- >>> include/uapi/linux/f2fs.h | 1 + >>> 5 files changed, 32 insertions(+), 7 deletions(-) >>> >>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c >>> index 5f895ddcd64a..bce4dcc3ad78 100644 >>> --- a/fs/f2fs/data.c >>> +++ b/fs/f2fs/data.c >>> @@ -3457,6 +3457,9 @@ static int prepare_atomic_write_begin(struct f2fs_sb_info *sbi, >>> else if (*blk_addr != NULL_ADDR) >>> return 0; >>> + if (is_inode_flag_set(inode, FI_ATOMIC_REPLACE)) >>> + goto reserve_block; >>> + >>> /* Look for the block in the original inode */ >>> err = __find_data_block(inode, index, &ori_blk_addr); >>> if (err) >>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >>> index e29f9adf60ca..d513ecd17550 100644 >>> --- a/fs/f2fs/f2fs.h >>> +++ b/fs/f2fs/f2fs.h >>> @@ -765,6 +765,7 @@ enum { >>> FI_ALIGNED_WRITE, /* enable aligned write */ >>> FI_COW_FILE, /* indicate COW file */ >>> FI_ATOMIC_COMMITTED, /* indicate atomic commit completed except disk sync */ >>> + FI_ATOMIC_REPLACE, /* indicate atomic replace */ >>> FI_MAX, /* max flag, never be used */ >>> }; >>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c >>> index 7ce629c95f4a..f9a04f6d76cb 100644 >>> --- a/fs/f2fs/file.c >>> +++ b/fs/f2fs/file.c >>> @@ -1984,7 +1984,7 @@ static int f2fs_ioc_getversion(struct file *filp, unsigned long arg) >>> return put_user(inode->i_generation, (int __user *)arg); >>> } >>> -static int f2fs_ioc_start_atomic_write(struct file *filp) >>> +static int f2fs_ioc_start_atomic_write(struct file *filp, bool truncate) >>> { >>> struct inode *inode = file_inode(filp); >>> struct user_namespace *mnt_userns = file_mnt_user_ns(filp); >>> @@ -2053,15 +2053,22 @@ static int f2fs_ioc_start_atomic_write(struct file *filp) >>> f2fs_write_inode(inode, NULL); >>> - isize = i_size_read(inode); >>> - fi->original_i_size = isize; >>> - f2fs_i_size_write(fi->cow_inode, isize); >>> - >>> stat_inc_atomic_inode(inode); >>> set_inode_flag(inode, FI_ATOMIC_FILE); >>> set_inode_flag(fi->cow_inode, FI_COW_FILE); >>> clear_inode_flag(fi->cow_inode, FI_INLINE_DATA); >>> + >>> + isize = i_size_read(inode); >>> + fi->original_i_size = isize; >>> + if (truncate) { >>> + set_inode_flag(inode, FI_ATOMIC_REPLACE); >>> + truncate_inode_pages_final(inode->i_mapping); >>> + f2fs_i_size_write(inode, 0); >>> + isize = 0; >>> + } >>> + f2fs_i_size_write(fi->cow_inode, isize); >>> + >>> f2fs_up_write(&fi->i_gc_rwsem[WRITE]); >>> f2fs_update_time(sbi, REQ_TIME); >>> @@ -4089,7 +4096,9 @@ static long __f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) >>> case FS_IOC_GETVERSION: >>> return f2fs_ioc_getversion(filp, arg); >>> case F2FS_IOC_START_ATOMIC_WRITE: >>> - return f2fs_ioc_start_atomic_write(filp); >>> + return f2fs_ioc_start_atomic_write(filp, false); >>> + case F2FS_IOC_START_ATOMIC_REPLACE: >>> + return f2fs_ioc_start_atomic_write(filp, true); >>> case F2FS_IOC_COMMIT_ATOMIC_WRITE: >>> return f2fs_ioc_commit_atomic_write(filp); >>> case F2FS_IOC_ABORT_ATOMIC_WRITE: >>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c >>> index 9cbf88092c78..f2930fffbc7d 100644 >>> --- a/fs/f2fs/segment.c >>> +++ b/fs/f2fs/segment.c >>> @@ -197,6 +197,7 @@ void f2fs_abort_atomic_write(struct inode *inode, bool clean) >>> fi->cow_inode = NULL; >>> release_atomic_write_cnt(inode); >>> clear_inode_flag(inode, FI_ATOMIC_COMMITTED); >>> + clear_inode_flag(inode, FI_ATOMIC_REPLACE); >>> clear_inode_flag(inode, FI_ATOMIC_FILE); >>> stat_dec_atomic_inode(inode); >>> @@ -261,14 +262,24 @@ static void __complete_revoke_list(struct inode *inode, struct list_head *head, >>> bool revoke) >>> { >>> struct revoke_entry *cur, *tmp; >>> + pgoff_t start_index = 0; >>> + bool truncate = is_inode_flag_set(inode, FI_ATOMIC_REPLACE); >>> list_for_each_entry_safe(cur, tmp, head, list) { >>> - if (revoke) >>> + if (revoke) { >>> __replace_atomic_write_block(inode, cur->index, >>> cur->old_addr, NULL, true); >>> + } else if (truncate) { >>> + f2fs_truncate_hole(inode, start_index, cur->index); >>> + start_index = cur->index + 1; >> >> Do we try to truncate from page #0 to page #(index of last page in chain)? >> >> If so, how about calling f2fs_truncate_hole(, 0, last_index) after the loop? > > I think either would be fine. Could you please send a separate patch for this?
Fine, let me add a new patch to clean up it.
Reviewed-by: Chao Yu <chao@kernel.org>
Thanks,
> >> >> Thanks, >> >>> + } >>> + >>> list_del(&cur->list); >>> kmem_cache_free(revoke_entry_slab, cur); >>> } >>> + >>> + if (!revoke && truncate) >>> + f2fs_do_truncate_blocks(inode, start_index * PAGE_SIZE, false); >>> } >>> static int __f2fs_commit_atomic_write(struct inode *inode) >>> diff --git a/include/uapi/linux/f2fs.h b/include/uapi/linux/f2fs.h >>> index 3121d127d5aa..955d440be104 100644 >>> --- a/include/uapi/linux/f2fs.h >>> +++ b/include/uapi/linux/f2fs.h >>> @@ -42,6 +42,7 @@ >>> struct f2fs_comp_option) >>> #define F2FS_IOC_DECOMPRESS_FILE _IO(F2FS_IOCTL_MAGIC, 23) >>> #define F2FS_IOC_COMPRESS_FILE _IO(F2FS_IOCTL_MAGIC, 24) >>> +#define F2FS_IOC_START_ATOMIC_REPLACE _IO(F2FS_IOCTL_MAGIC, 25) >>> /* >>> * should be same as XFS_IOC_GOINGDOWN. >> >> >> _______________________________________________ >> Linux-f2fs-devel mailing list >> Linux-f2fs-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
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