Hi Wanpeng, > -----Original Message----- > From: Wanpeng Li [mailto:[email protected]] > Sent: Thursday, March 19, 2015 7:02 AM > To: Jaegeuk Kim > Cc: Wanpeng Li; Changman Lee; Chao Yu; [email protected]; > [email protected]; [email protected] > Subject: Re: [PATCH v3] f2fs: add fast symlink support > > Hi Jaegeuk, > On Wed, Mar 18, 2015 at 11:05:28AM -0700, Jaegeuk Kim wrote: > >Hi, > > > >On Wed, Mar 18, 2015 at 04:58:52PM +0800, Wanpeng Li wrote: > >> Hi Jaegeuk, > >> On Tue, Mar 17, 2015 at 10:21:27AM -0700, Jaegeuk Kim wrote: > >> >> - err = page_symlink(inode, symname, symlen); > >> >> + > >> >> + if (symlen > MAX_FAST_SYMLINK_SIZE) { > >> >> + /* slow symlink */ > >> >> + inode->i_op = &f2fs_symlink_inode_operations; > >> >> + inode->i_mapping->a_ops = &f2fs_dblock_aops; > >> >> + err = page_symlink(inode, symname, symlen); > >> >> + } else { > >> >> + /* fast symlink */ > >> >> + struct page *node_page; > >> >> + > >> >> + inode->i_op = &f2fs_fast_symlink_inode_operations; > >> >> + node_page = get_node_page(sbi, inode->i_ino); > >> >> + memcpy((char *)&F2FS_INODE(node_page)->i_addr, symname, > >> >> symlen); > >> > > >> >This is mostly likewise the inline_data flow. > >> >As of now, I can't recommend using any i_addr region, since we need to > >> >handle > >> >many cases such as truncation, roll-forward recovery, and fsck/dump tools. > >> > > >> >It is more sensible to enable inline_data by default, isn't it? > >> > >> Do you mean to replace the codes above by something like > >> f2fs_write_inline_data()? > > > >I meant the mount option, inline_data. > >Currently, f2fs doesn't set that option at mount time, but I thought that we > >can set it by default since it becomes stable. > > So I think you mean my codes should memcpy i_addr[1~872] instead of > i_addr[0~872], right?
I think what Jaegeuk means is that we can use inline_data in f2fs by default with patch like below firstly: >From a7320bfe94239ea4ceb193621a3a1a4d11a40d07 Mon Sep 17 00:00:00 2001 From: Chao Yu <[email protected]> Date: Thu, 19 Mar 2015 10:02:08 +0800 Subject: [PATCH] f2fs: use inline_data by default Use inline_data feature by default since it brings us better performance & space utilization and now it is already stable. Suggested-by: Jaegeuk Kim <[email protected]> Signed-off-by: Chao Yu <[email protected]> Signed-off-by: Wanpeng Li <[email protected]> --- fs/f2fs/super.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index fc6857f..8772d91 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -991,6 +991,7 @@ try_onemore: sbi->active_logs = NR_CURSEG_TYPE; set_opt(sbi, BG_GC); + set_opt(sbi, INLINE_DATA); #ifdef CONFIG_F2FS_FS_XATTR set_opt(sbi, XATTR_USER); -- 2.3.1 Then we enable inline_data feature for symlink in f2fs_may_inline, after that by default our symlink created has inline_data flag in it, we treat small size symlink as an inline regular file, we can write its data page which is written in page_symlink into inode page like normal inline data procedure. Thanks, > > Regards, > Wanpeng Li > > > > >Thanks, > > > >> > >> Regards, > >> Wanpeng Li > >> > >> > > >> >Thanks, > >> > > >> >> + set_page_dirty(node_page); > >> >> + f2fs_put_page(node_page, 1); > >> >> + inode->i_size = symlen-1; > >> >> + set_inode_flag(F2FS_I(inode), FI_FAST_SYMLINK); > >> >> + mark_inode_dirty(inode); > >> >> + } > >> >> alloc_nid_done(sbi, inode->i_ino); > >> >> > >> >> d_instantiate(dentry, inode); > >> >> @@ -743,6 +774,20 @@ const struct inode_operations > >> >> f2fs_symlink_inode_operations = { > >> >> #endif > >> >> }; > >> >> > >> >> +const struct inode_operations f2fs_fast_symlink_inode_operations = { > >> >> + .readlink = generic_readlink, > >> >> + .follow_link = f2fs_follow_link, > >> >> + .put_link = page_put_link, > >> >> + .getattr = f2fs_getattr, > >> >> + .setattr = f2fs_setattr, > >> >> +#ifdef CONFIG_F2FS_FS_XATTR > >> >> + .setxattr = generic_setxattr, > >> >> + .getxattr = generic_getxattr, > >> >> + .listxattr = f2fs_listxattr, > >> >> + .removexattr = generic_removexattr, > >> >> +#endif > >> >> +}; > >> >> + > >> >> const struct inode_operations f2fs_special_inode_operations = { > >> >> .getattr = f2fs_getattr, > >> >> .setattr = f2fs_setattr, > >> >> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > >> >> index 35a9117..efe28a2b 100644 > >> >> --- a/fs/f2fs/node.c > >> >> +++ b/fs/f2fs/node.c > >> >> @@ -908,8 +908,9 @@ void remove_inode_page(struct inode *inode) > >> >> } > >> >> > >> >> /* remove potential inline_data blocks */ > >> >> - if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || > >> >> - S_ISLNK(inode->i_mode)) > >> >> + if ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || > >> >> + S_ISLNK(inode->i_mode)) && > >> >> + !f2fs_inode_is_fast_symlink(inode)) > >> >> truncate_data_blocks_range(&dn, 1); > >> >> > >> >> /* 0 is possible, after f2fs_new_inode() has failed */ > >> >> diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h > >> >> index 502f28c..834880c 100644 > >> >> --- a/include/linux/f2fs_fs.h > >> >> +++ b/include/linux/f2fs_fs.h > >> >> @@ -178,9 +178,11 @@ struct f2fs_extent { > >> >> #define F2FS_INLINE_DATA 0x02 /* file inline data flag */ > >> >> #define F2FS_INLINE_DENTRY 0x04 /* file inline dentry flag */ > >> >> #define F2FS_DATA_EXIST 0x08 /* file inline data > >> >> exist flag */ > >> >> +#define F2FS_FAST_SYMLINK 0x10 /* file fast symlink flag */ > >> >> > >> >> #define MAX_INLINE_DATA (sizeof(__le32) * > >> >> (DEF_ADDRS_PER_INODE - \ > >> >> F2FS_INLINE_XATTR_ADDRS > >> >> - 1)) > >> >> +#define MAX_FAST_SYMLINK_SIZE (MAX_INLINE_DATA + 1) > >> >> > >> >> struct f2fs_inode { > >> >> __le16 i_mode; /* file mode */ > >> >> -- > >> >> 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
