On Fri 16-08-24 01:22:37, Christoph Hellwig wrote: > On Fri, Aug 16, 2024 at 10:17:54AM +0200, Michal Hocko wrote: > > Andrew, could you merge the following before PF_MEMALLOC_NORECLAIM can > > be removed from the tree altogether please? For the full context the > > email thread starts here: https://lore.kernel.org/all/20240812090525.80299-1-laoar.shao@xxxxxxxxx/T/#u > > I don't think that's enough. We just need to kill it given that it was > added without ACKs and despite explicit earlier objections to the API. Yes, I think we should kill it before it spreads even more but I would not like to make the existing user just broken. I have zero visibility and understanding of the bcachefs code but from a quick look at __bch2_new_inode it shouldn't be really terribly hard to push GFP_NOWAIT flag there directly. It would require inode_init_always_gfp variant as well (to not touch all existing callers that do not have any locking requirements but I do not see any other nested allocations. So a very quick and untested change would look as follows: --- diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c index 15fc41e63b6c..7a55167b9133 100644 --- a/fs/bcachefs/fs.c +++ b/fs/bcachefs/fs.c @@ -231,9 +231,9 @@ static struct inode *bch2_alloc_inode(struct super_block *sb) BUG(); } -static struct bch_inode_info *__bch2_new_inode(struct bch_fs *c) +static struct bch_inode_info *__bch2_new_inode(struct bch_fs *c, gfp_t gfp) { - struct bch_inode_info *inode = kmem_cache_alloc(bch2_inode_cache, GFP_NOFS); + struct bch_inode_info *inode = kmem_cache_alloc(bch2_inode_cache, gfp); if (!inode) return NULL; @@ -245,7 +245,7 @@ static struct bch_inode_info *__bch2_new_inode(struct bch_fs *c) mutex_init(&inode->ei_quota_lock); memset(&inode->ei_devs_need_flush, 0, sizeof(inode->ei_devs_need_flush)); - if (unlikely(inode_init_always(c->vfs_sb, &inode->v))) { + if (unlikely(inode_init_always_gfp(c->vfs_sb, &inode->v), gfp)) { kmem_cache_free(bch2_inode_cache, inode); return NULL; } @@ -258,12 +258,10 @@ static struct bch_inode_info *__bch2_new_inode(struct bch_fs *c) */ static struct bch_inode_info *bch2_new_inode(struct btree_trans *trans) { - struct bch_inode_info *inode = - memalloc_flags_do(PF_MEMALLOC_NORECLAIM|PF_MEMALLOC_NOWARN, - __bch2_new_inode(trans->c)); + struct bch_inode_info *inode = __bch2_new_inode(trans->c, GFP_NOWARN | GFP_NOWAIT); if (unlikely(!inode)) { - int ret = drop_locks_do(trans, (inode = __bch2_new_inode(trans->c)) ? 0 : -ENOMEM); + int ret = drop_locks_do(trans, (inode = __bch2_new_inode(trans->c, GFP_NOFS)) ? 0 : -ENOMEM); if (ret && inode) { __destroy_inode(&inode->v); kmem_cache_free(bch2_inode_cache, inode); @@ -328,7 +326,7 @@ __bch2_create(struct mnt_idmap *idmap, if (ret) return ERR_PTR(ret); #endif - inode = __bch2_new_inode(c); + inode = __bch2_new_inode(c, GFP_NOFS); if (unlikely(!inode)) { inode = ERR_PTR(-ENOMEM); goto err; diff --git a/fs/inode.c b/fs/inode.c index 86670941884b..95fd67a6cac3 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -153,7 +153,7 @@ static int no_open(struct inode *inode, struct file *file) * These are initializations that need to be done on every inode * allocation as the fields are not initialised by slab allocation. */ -int inode_init_always(struct super_block *sb, struct inode *inode) +int inode_init_always(struct super_block *sb, struct inode *inode, gfp_t gfp) { static const struct inode_operations empty_iops; static const struct file_operations no_open_fops = {.open = no_open}; @@ -230,14 +230,14 @@ int inode_init_always(struct super_block *sb, struct inode *inode) #endif inode->i_flctx = NULL; - if (unlikely(security_inode_alloc(inode))) + if (unlikely(security_inode_alloc(inode, gfp))) return -ENOMEM; this_cpu_inc(nr_inodes); return 0; } -EXPORT_SYMBOL(inode_init_always); +EXPORT_SYMBOL(inode_init_always_gfp); void free_inode_nonrcu(struct inode *inode) { diff --git a/include/linux/fs.h b/include/linux/fs.h index fd34b5755c0b..5c613a89718b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3027,7 +3027,12 @@ extern loff_t default_llseek(struct file *file, loff_t offset, int whence); extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence); -extern int inode_init_always(struct super_block *, struct inode *); +extern int inode_init_always(struct super_block *, struct inode *, gfp_t); +static inline int inode_init_always(struct super_block *, struct inode *) +{ + return inode_init_always_gfp(GFP_NOFS); +} + extern void inode_init_once(struct inode *); extern void address_space_init_once(struct address_space *mapping); extern struct inode * igrab(struct inode *); diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index a2ade0ffe9e7..b08472d64765 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -150,6 +150,6 @@ extern struct lsm_info __start_early_lsm_info[], __end_early_lsm_info[]; __used __section(".early_lsm_info.init") \ __aligned(sizeof(unsigned long)) -extern int lsm_inode_alloc(struct inode *inode); +extern int lsm_inode_alloc(struct inode *inode, gfp_t gfp); #endif /* ! __LINUX_LSM_HOOKS_H */ diff --git a/include/linux/security.h b/include/linux/security.h index 1390f1efb4f0..7c6b9b038a0d 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -336,7 +336,7 @@ int security_dentry_create_files_as(struct dentry *dentry, int mode, struct cred *new); int security_path_notify(const struct path *path, u64 mask, unsigned int obj_type); -int security_inode_alloc(struct inode *inode); +int security_inode_alloc(struct inode *inode, gfp_t gfp); void security_inode_free(struct inode *inode); int security_inode_init_security(struct inode *inode, struct inode *dir, const struct qstr *qstr, @@ -769,7 +769,7 @@ static inline int security_path_notify(const struct path *path, u64 mask, return 0; } -static inline int security_inode_alloc(struct inode *inode) +static inline int security_inode_alloc(struct inode *inode, gfp_t gfp) { return 0; } diff --git a/security/security.c b/security/security.c index 8cee5b6c6e6d..8634d3bee56f 100644 --- a/security/security.c +++ b/security/security.c @@ -660,14 +660,14 @@ static int lsm_file_alloc(struct file *file) * * Returns 0, or -ENOMEM if memory can't be allocated. */ -int lsm_inode_alloc(struct inode *inode) +int lsm_inode_alloc(struct inode *inode, gfp) { if (!lsm_inode_cache) { inode->i_security = NULL; return 0; } - inode->i_security = kmem_cache_zalloc(lsm_inode_cache, GFP_NOFS); + inode->i_security = kmem_cache_zalloc(lsm_inode_cache, gfp); if (inode->i_security == NULL) return -ENOMEM; return 0; @@ -1582,9 +1582,9 @@ int security_path_notify(const struct path *path, u64 mask, * * Return: Return 0 if operation was successful. */ -int security_inode_alloc(struct inode *inode) +int security_inode_alloc(struct inode *inode, gfp_t gfp) { - int rc = lsm_inode_alloc(inode); + int rc = lsm_inode_alloc(inode, gfp); if (unlikely(rc)) return rc; -- Michal Hocko SUSE Labs
