Messages in this thread Patch in this message | | | Date | Tue, 5 May 2020 11:13:23 -0700 | From | Jaegeuk Kim <> | Subject | Re: [f2fs-dev] [PATCH] f2fs: get parent inode when recovering pino |
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On 05/05, Eric Biggers wrote: > On Tue, May 05, 2020 at 08:31:39AM -0700, Jaegeuk Kim wrote: > > We had to grab the inode before retrieving i_ino. > > > > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> > > --- > > fs/f2fs/file.c | 8 +++++++- > > 1 file changed, 7 insertions(+), 1 deletion(-) > > > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > > index a0a4413d6083b..9d4c3e3503567 100644 > > --- a/fs/f2fs/file.c > > +++ b/fs/f2fs/file.c > > @@ -168,6 +168,7 @@ static const struct vm_operations_struct f2fs_file_vm_ops = { > > static int get_parent_ino(struct inode *inode, nid_t *pino) > > { > > struct dentry *dentry; > > + struct inode *parent; > > > > inode = igrab(inode); > > dentry = d_find_any_alias(inode); > > @@ -175,8 +176,13 @@ static int get_parent_ino(struct inode *inode, nid_t *pino) > > if (!dentry) > > return 0; > > > > - *pino = parent_ino(dentry); > > + parent = igrab(d_inode(dentry->d_parent)); > > dput(dentry); > > + if (!parent) > > + return 0; > > + > > + *pino = parent->i_ino; > > + iput(parent); > > return 1;
Hi Eric,
> > This doesn't appear to be necessary. parent_ino() is: > > spin_lock(&dentry->d_lock); > res = dentry->d_parent->d_inode->i_ino; > spin_unlock(&dentry->d_lock); > > Since dentry is locked and referenced, ->d_parent is stable and positive.
I see, thanks. :)
> > In the encrypt+casefold patch I was reviewing, it's indeed necessary, but only > because there was a check of inode->i_flags added outside the locked region. > The following would be simpler: > > spin_lock(&dentry->d_lock); > dir = dentry->d_parent->d_inode; > *pino = dir->i_ino; > needs_recovery = IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir); > spin_unlock(&dentry->d_lock);
Ack.
> > BTW, d_find_any_alias() is unnecessary too. This code should just be using > file_dentry(file) from f2fs_do_sync_file().
How about this?
From 9aee969a413b1ed22b48573071bc93fbb4a2002d Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim <jaegeuk@kernel.org> Date: Tue, 5 May 2020 11:08:58 -0700 Subject: [PATCH] f2fs: remove unnecessary dentry locks
As Eric commented, let's kill unnecessary dentry ops when recovering parent inode number.
Suggested-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> --- fs/f2fs/file.c | 26 ++++++-------------------- 1 file changed, 6 insertions(+), 20 deletions(-)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index a0a4413d6083b..711cebad36fc5 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -165,21 +165,6 @@ static const struct vm_operations_struct f2fs_file_vm_ops = { .page_mkwrite = f2fs_vm_page_mkwrite, }; -static int get_parent_ino(struct inode *inode, nid_t *pino) -{ - struct dentry *dentry; - - inode = igrab(inode); - dentry = d_find_any_alias(inode); - iput(inode); - if (!dentry) - return 0; - - *pino = parent_ino(dentry); - dput(dentry); - return 1; -} - static inline enum cp_reason_type need_do_checkpoint(struct inode *inode) { struct f2fs_sb_info *sbi = F2FS_I_SB(inode); @@ -223,14 +208,15 @@ static bool need_inode_page_update(struct f2fs_sb_info *sbi, nid_t ino) return ret; } -static void try_to_fix_pino(struct inode *inode) +static void try_to_fix_pino(struct dentry *dentry) { + struct inode *inode = d_inode(dentry); struct f2fs_inode_info *fi = F2FS_I(inode); - nid_t pino; down_write(&fi->i_sem); - if (file_wrong_pino(inode) && inode->i_nlink == 1 && - get_parent_ino(inode, &pino)) { + if (file_wrong_pino(inode) && inode->i_nlink == 1) { + nid_t pino = parent_ino(dentry); + f2fs_i_pino_write(inode, pino); file_got_pino(inode); } @@ -310,7 +296,7 @@ static int f2fs_do_sync_file(struct file *file, loff_t start, loff_t end, * We've secured consistency through sync_fs. Following pino * will be used only for fsynced inodes after checkpoint. */ - try_to_fix_pino(inode); + try_to_fix_pino(file_dentry(file)); clear_inode_flag(inode, FI_APPEND_WRITE); clear_inode_flag(inode, FI_UPDATE_WRITE); goto out; -- 2.26.2.526.g744177e7f7-goog
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