| Message ID | 20180517085305.GA23785@veci.piliscsaba.redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, May 17, 2018 at 11:53 AM, Miklos Szeredi <miklos@szeredi.hu> wrote: > On Thu, May 17, 2018 at 10:10:58AM +0200, Miklos Szeredi wrote: >> >> Not the only reason: we don't want inode allocation to fail after >> successful creation. Solution: add a preallocated inode argument to >> ovl_get_inode() and deal with allocation failure there. > > Here's a patch to split a helper out of iget5_locked() that takes a preallocated > inode. It makes the whole thing more readable, IMO, regardless of overlayfs's > needs. > That looks good. I'll use that. One suggestion below. Thanks, Amir. > > --- > diff --git a/fs/inode.c b/fs/inode.c > index 13ceb98c3bd3..bb79e3f96147 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -1002,6 +1002,52 @@ void unlock_two_nondirectories(struct inode *inode1, struct inode *inode2) > } > EXPORT_SYMBOL(unlock_two_nondirectories); > > +struct inode *iget5_prealloc(struct inode *inode, > + struct super_block *sb, unsigned long hashval, Maybe no need to pass in @sb... > + int (*test)(struct inode *, void *), > + int (*set)(struct inode *, void *), void *data) > +{ > + struct hlist_head *head = inode_hashtable + hash(sb, hashval); > + struct inode *old; > + > +again: > + spin_lock(&inode_hash_lock); > + old = find_inode(sb, head, test, data); > + if (unlikely(old)) { > + /* > + * Uhhuh, somebody else created the same inode under us. > + * Use the old inode instead of the preallocated one. > + */ > + spin_unlock(&inode_hash_lock); > + wait_on_inode(old); > + if (unlikely(inode_unhashed(old))) { > + iput(old); > + goto again; > + } > + return old; > + } > + > + if (unlikely(set(inode, data))) { > + inode = NULL; > + goto unlock; > + } > + > + /* > + * Return the locked inode with I_NEW set, the > + * caller is responsible for filling in the contents > + */ > + spin_lock(&inode->i_lock); > + inode->i_state = I_NEW; > + hlist_add_head(&inode->i_hash, head); > + spin_unlock(&inode->i_lock); > + inode_sb_list_add(inode); > +unlock: > + spin_unlock(&inode_hash_lock); > + > + return inode; > +} > +EXPORT_SYMBOL(iget5_prealloc); > + > /** > * iget5_locked - obtain an inode from a mounted file system > * @sb: super block of file system > @@ -1026,66 +1072,18 @@ struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, > int (*test)(struct inode *, void *), > int (*set)(struct inode *, void *), void *data) > { > - struct hlist_head *head = inode_hashtable + hash(sb, hashval); > - struct inode *inode; > -again: > - spin_lock(&inode_hash_lock); > - inode = find_inode(sb, head, test, data); > - spin_unlock(&inode_hash_lock); > + struct inode *inode = ilookup5(sb, hashval, test, data); > > - if (inode) { > - wait_on_inode(inode); > - if (unlikely(inode_unhashed(inode))) { > - iput(inode); > - goto again; > - } > - return inode; > - } > - > - inode = alloc_inode(sb); > - if (inode) { > - struct inode *old; > - > - spin_lock(&inode_hash_lock); > - /* We released the lock, so.. */ > - old = find_inode(sb, head, test, data); > - if (!old) { > - if (set(inode, data)) > - goto set_failed; > - > - spin_lock(&inode->i_lock); > - inode->i_state = I_NEW; > - hlist_add_head(&inode->i_hash, head); > - spin_unlock(&inode->i_lock); > - inode_sb_list_add(inode); > - spin_unlock(&inode_hash_lock); > - > - /* Return the locked inode with I_NEW set, the > - * caller is responsible for filling in the contents > - */ > - return inode; > - } > + if (!inode) { > + struct inode *new = alloc_inode(sb); > > - /* > - * Uhhuh, somebody else created the same inode under > - * us. Use the old inode instead of the one we just > - * allocated. > - */ > - spin_unlock(&inode_hash_lock); > - destroy_inode(inode); > - inode = old; > - wait_on_inode(inode); > - if (unlikely(inode_unhashed(inode))) { > - iput(inode); > - goto again; > + if (new) { > + inode = iget5_prealloc(new, sb, hashval, test, set, data); > + if (inode != new) > + destroy_inode(new); > } > } > return inode; > - > -set_failed: > - spin_unlock(&inode_hash_lock); > - destroy_inode(inode); > - return NULL; > } > EXPORT_SYMBOL(iget5_locked); >
On Thu, May 17, 2018 at 10:58 AM, Amir Goldstein <amir73il@gmail.com> wrote: >> --- >> diff --git a/fs/inode.c b/fs/inode.c >> index 13ceb98c3bd3..bb79e3f96147 100644 >> --- a/fs/inode.c >> +++ b/fs/inode.c >> @@ -1002,6 +1002,52 @@ void unlock_two_nondirectories(struct inode *inode1, struct inode *inode2) >> } >> EXPORT_SYMBOL(unlock_two_nondirectories); >> >> +struct inode *iget5_prealloc(struct inode *inode, >> + struct super_block *sb, unsigned long hashval, > > Maybe no need to pass in @sb... Yep. Thanks, Miklos
On Thu, May 17, 2018 at 12:07 PM, Miklos Szeredi <miklos@szeredi.hu> wrote: > On Thu, May 17, 2018 at 10:58 AM, Amir Goldstein <amir73il@gmail.com> wrote: > >>> --- >>> diff --git a/fs/inode.c b/fs/inode.c >>> index 13ceb98c3bd3..bb79e3f96147 100644 >>> --- a/fs/inode.c >>> +++ b/fs/inode.c >>> @@ -1002,6 +1002,52 @@ void unlock_two_nondirectories(struct inode *inode1, struct inode *inode2) >>> } >>> EXPORT_SYMBOL(unlock_two_nondirectories); >>> >>> +struct inode *iget5_prealloc(struct inode *inode, >>> + struct super_block *sb, unsigned long hashval, >> >> Maybe no need to pass in @sb... > Pushed new version with iget5_prealloc() and another cleanup patch from Vivek to: https://github.com/amir73il/linux/commits/ovl-fixes It passed xfstest overlay/quick. Will run some more tests tomorrow and post the patches. Thanks, Amir.
diff --git a/fs/inode.c b/fs/inode.c index 13ceb98c3bd3..bb79e3f96147 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1002,6 +1002,52 @@ void unlock_two_nondirectories(struct inode *inode1, struct inode *inode2) } EXPORT_SYMBOL(unlock_two_nondirectories); +struct inode *iget5_prealloc(struct inode *inode, + struct super_block *sb, unsigned long hashval, + int (*test)(struct inode *, void *), + int (*set)(struct inode *, void *), void *data) +{ + struct hlist_head *head = inode_hashtable + hash(sb, hashval); + struct inode *old; + +again: + spin_lock(&inode_hash_lock); + old = find_inode(sb, head, test, data); + if (unlikely(old)) { + /* + * Uhhuh, somebody else created the same inode under us. + * Use the old inode instead of the preallocated one. + */ + spin_unlock(&inode_hash_lock); + wait_on_inode(old); + if (unlikely(inode_unhashed(old))) { + iput(old); + goto again; + } + return old; + } + + if (unlikely(set(inode, data))) { + inode = NULL; + goto unlock; + } + + /* + * Return the locked inode with I_NEW set, the + * caller is responsible for filling in the contents + */ + spin_lock(&inode->i_lock); + inode->i_state = I_NEW; + hlist_add_head(&inode->i_hash, head); + spin_unlock(&inode->i_lock); + inode_sb_list_add(inode); +unlock: + spin_unlock(&inode_hash_lock); + + return inode; +} +EXPORT_SYMBOL(iget5_prealloc); + /** * iget5_locked - obtain an inode from a mounted file system * @sb: super block of file system @@ -1026,66 +1072,18 @@ struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *data) { - struct hlist_head *head = inode_hashtable + hash(sb, hashval); - struct inode *inode; -again: - spin_lock(&inode_hash_lock); - inode = find_inode(sb, head, test, data); - spin_unlock(&inode_hash_lock); + struct inode *inode = ilookup5(sb, hashval, test, data); - if (inode) { - wait_on_inode(inode); - if (unlikely(inode_unhashed(inode))) { - iput(inode); - goto again; - } - return inode; - } - - inode = alloc_inode(sb); - if (inode) { - struct inode *old; - - spin_lock(&inode_hash_lock); - /* We released the lock, so.. */ - old = find_inode(sb, head, test, data); - if (!old) { - if (set(inode, data)) - goto set_failed; - - spin_lock(&inode->i_lock); - inode->i_state = I_NEW; - hlist_add_head(&inode->i_hash, head); - spin_unlock(&inode->i_lock); - inode_sb_list_add(inode); - spin_unlock(&inode_hash_lock); - - /* Return the locked inode with I_NEW set, the - * caller is responsible for filling in the contents - */ - return inode; - } + if (!inode) { + struct inode *new = alloc_inode(sb); - /* - * Uhhuh, somebody else created the same inode under - * us. Use the old inode instead of the one we just - * allocated. - */ - spin_unlock(&inode_hash_lock); - destroy_inode(inode); - inode = old; - wait_on_inode(inode); - if (unlikely(inode_unhashed(inode))) { - iput(inode); - goto again; + if (new) { + inode = iget5_prealloc(new, sb, hashval, test, set, data); + if (inode != new) + destroy_inode(new); } } return inode; - -set_failed: - spin_unlock(&inode_hash_lock); - destroy_inode(inode); - return NULL; } EXPORT_SYMBOL(iget5_locked);