Messages in this thread | | | Date | Tue, 5 May 2020 09:58:47 -0700 | From | Eric Biggers <> | Subject | Re: [f2fs-dev] [PATCH] f2fs: get parent inode when recovering pino |
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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;
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.
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);
BTW, d_find_any_alias() is unnecessary too. This code should just be using file_dentry(file) from f2fs_do_sync_file().
- Eric
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