RE: [PATCH v2] f2fs: add fast symlink support

From: Chao Yu
Date: Thu Mar 12 2015 - 08:11:18 EST

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In reply to: Wanpeng Li: "[PATCH v2] f2fs: add fast symlink support"
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Hi Wanpeng,

> -----Original Message-----
> From: Wanpeng Li [mailto:wanpeng.li@xxxxxxxxxxxxxxx]
> Sent: Thursday, March 12, 2015 5:12 PM
> To: Jaegeuk Kim
> Cc: Changman Lee; Chao Yu; linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx;
> linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Wanpeng Li
> Subject: [PATCH v2] f2fs: add fast symlink support
>
> This patch introduces the improvement fast symlinks to allow storage of
> the target path within inode, thus symlinks with short target paths are
> more accessed quickly. It will fall back to using the original slow
> symlink if the target path exceeds the available inode space.
>
> Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxxxxxx>
> ---
> v1 -> v2:
> * set max size of fast symlink according to inline_xattr flag
>
> fs/f2fs/f2fs.h | 20 +++++++++++++++++++
> fs/f2fs/file.c | 2 ++
> fs/f2fs/inode.c | 9 +++++++--
> fs/f2fs/namei.c | 53 +++++++++++++++++++++++++++++++++++++++++++++----
> include/linux/f2fs_fs.h | 1 +
> 5 files changed, 79 insertions(+), 6 deletions(-)
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 511d6cd..9cc4287 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -1226,6 +1226,7 @@ enum {
> FI_VOLATILE_FILE, /* indicate volatile file */
> FI_DROP_CACHE, /* drop dirty page cache */
> FI_DATA_EXIST, /* indicate data exists */
> + FI_FAST_SYMLINK, /* indicate fast symlink */
> };
>
> static inline void set_inode_flag(struct f2fs_inode_info *fi, int flag)
> @@ -1262,6 +1263,8 @@ static inline void get_inline_info(struct f2fs_inode_info *fi,
> set_inode_flag(fi, FI_INLINE_DENTRY);
> if (ri->i_inline & F2FS_DATA_EXIST)
> set_inode_flag(fi, FI_DATA_EXIST);
> + if (ri->i_inline & F2FS_FAST_SYMLINK)
> + set_inode_flag(fi, FI_FAST_SYMLINK);
> }
>
> static inline void set_raw_inline(struct f2fs_inode_info *fi,
> @@ -1277,6 +1280,8 @@ static inline void set_raw_inline(struct f2fs_inode_info *fi,
> ri->i_inline |= F2FS_INLINE_DENTRY;
> if (is_inode_flag_set(fi, FI_DATA_EXIST))
> ri->i_inline |= F2FS_DATA_EXIST;
> + if (is_inode_flag_set(fi, FI_FAST_SYMLINK))
> + ri->i_inline |= F2FS_FAST_SYMLINK;
> }
>
> static inline int f2fs_has_inline_xattr(struct inode *inode)
> @@ -1370,6 +1375,15 @@ static inline void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi)
> sbi->sb->s_flags |= MS_RDONLY;
> }
>
> +/*
> + * Test whether an inode is a fast symlink.
> + */
> +static inline int f2fs_inode_is_fast_symlink(struct inode *inode)
> +{
> + return (S_ISLNK(inode->i_mode) &&
> + is_inode_flag_set(F2FS_I(inode), FI_FAST_SYMLINK));
> +}
> +
> #define get_inode_mode(i) \
> ((is_inode_flag_set(F2FS_I(i), FI_ACL_MODE)) ? \
> (F2FS_I(i)->i_acl_mode) : ((i)->i_mode))
> @@ -1411,6 +1425,11 @@ void handle_failed_inode(struct inode *);
> */
> struct dentry *f2fs_get_parent(struct dentry *child);
>
> +static inline unsigned int max_fast_symlink_size(struct inode *inode)
> +{
> + return sizeof(__le32) * addrs_per_inode(F2FS_I(inode));
> +}
> +
> /*
> * dir.c
> */
> @@ -1746,6 +1765,7 @@ extern const struct address_space_operations f2fs_node_aops;
> extern const struct address_space_operations f2fs_meta_aops;
> extern const struct inode_operations f2fs_dir_inode_operations;
> extern const struct inode_operations f2fs_symlink_inode_operations;
> +extern const struct inode_operations f2fs_fast_symlink_inode_operations;
> extern const struct inode_operations f2fs_special_inode_operations;
> extern struct kmem_cache *inode_entry_slab;
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index f1341c7..05a3d4f 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -546,6 +546,8 @@ void f2fs_truncate(struct inode *inode)
> if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
> S_ISLNK(inode->i_mode)))
> return;
> + if (f2fs_inode_is_fast_symlink(inode))

We should handle fast symlink in remove_inode_page to avoid invoking
truncate_data_blocks_range incorrectly.

Thanks,

> + return;
>
> trace_f2fs_truncate(inode);
>
> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> index b508744..ec9ad22 100644
> --- a/fs/f2fs/inode.c
> +++ b/fs/f2fs/inode.c
> @@ -13,6 +13,7 @@
> #include <linux/buffer_head.h>
> #include <linux/writeback.h>
> #include <linux/bitops.h>
> +#include <linux/namei.h>
>
> #include "f2fs.h"
> #include "node.h"
> @@ -188,8 +189,12 @@ make_now:
> inode->i_mapping->a_ops = &f2fs_dblock_aops;
> mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_HIGH_ZERO);
> } else if (S_ISLNK(inode->i_mode)) {
> - inode->i_op = &f2fs_symlink_inode_operations;
> - inode->i_mapping->a_ops = &f2fs_dblock_aops;
> + if (f2fs_inode_is_fast_symlink(inode))
> + inode->i_op = &f2fs_fast_symlink_inode_operations;
> + else {
> + inode->i_op = &f2fs_symlink_inode_operations;
> + inode->i_mapping->a_ops = &f2fs_dblock_aops;
> + }
> } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
> S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
> inode->i_op = &f2fs_special_inode_operations;
> diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
> index 1e2ae21..ab75ad6 100644
> --- a/fs/f2fs/namei.c
> +++ b/fs/f2fs/namei.c
> @@ -14,6 +14,7 @@
> #include <linux/sched.h>
> #include <linux/ctype.h>
> #include <linux/dcache.h>
> +#include <linux/namei.h>
>
> #include "f2fs.h"
> #include "node.h"
> @@ -247,6 +248,21 @@ fail:
> return err;
> }
>
> +static void *f2fs_follow_link(struct dentry *dentry, struct nameidata *nd)
> +{
> + struct page *node_page;
> +
> + node_page = get_node_page(F2FS_I_SB(dentry->d_inode),
> + dentry->d_inode->i_ino);
> + if (IS_ERR(node_page)) {
> + nd_set_link(nd, NULL);
> + return NULL;
> + }
> + nd_set_link(nd, (char *)(F2FS_INODE(node_page)->i_addr));
> + f2fs_put_page(node_page, 1);
> + return NULL;
> +}
> +
> static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
> const char *symname)
> {
> @@ -261,16 +277,31 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
> if (IS_ERR(inode))
> return PTR_ERR(inode);
>
> - inode->i_op = &f2fs_symlink_inode_operations;
> - inode->i_mapping->a_ops = &f2fs_dblock_aops;
> -
> f2fs_lock_op(sbi);
> err = f2fs_add_link(dentry, inode);
> if (err)
> goto out;
> f2fs_unlock_op(sbi);
>
> - err = page_symlink(inode, symname, symlen);
> +
> + if (symlen > max_fast_symlink_size(inode)) {
> + /* 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);
> + 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/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> index 502f28c..a317234 100644
> --- a/include/linux/f2fs_fs.h
> +++ b/include/linux/f2fs_fs.h
> @@ -178,6 +178,7 @@ 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))
> --
> 2.1.0

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Next message: James Bottomley: "Re: [PATCH 14/22] parisc: %pF is only for function pointers"
Previous message: Alexandre Belloni: "[PATCH v5 03/10] watchdog: at91rm9200: use the system timer syscon"
In reply to: Wanpeng Li: "[PATCH v2] f2fs: add fast symlink support"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]