From 9897713fe1077c90b4a86c9af0a878d56c8888a2 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 26 Sep 2024 19:11:50 +0200 Subject: bcachefs: do not use PF_MEMALLOC_NORECLAIM Patch series "remove PF_MEMALLOC_NORECLAIM" v3. This patch (of 2): bch2_new_inode relies on PF_MEMALLOC_NORECLAIM to try to allocate a new inode to achieve GFP_NOWAIT semantic while holding locks. If this allocation fails it will drop locks and use GFP_NOFS allocation context. We would like to drop PF_MEMALLOC_NORECLAIM because it is really dangerous to use if the caller doesn't control the full call chain with this flag set. E.g. if any of the function down the chain needed GFP_NOFAIL request the PF_MEMALLOC_NORECLAIM would override this and cause unexpected failure. While this is not the case in this particular case using the scoped gfp semantic is not really needed bacause we can easily pus the allocation context down the chain without too much clutter. [akpm@linux-foundation.org: fix kerneldoc warnings] Link: https://lkml.kernel.org/r/20240926172940.167084-1-mhocko@kernel.org Link: https://lkml.kernel.org/r/20240926172940.167084-2-mhocko@kernel.org Signed-off-by: Michal Hocko Reviewed-by: Christoph Hellwig Reviewed-by: Dave Chinner Reviewed-by: Jan Kara # For vfs changes Cc: Al Viro Cc: Christian Brauner Cc: James Morris Cc: Kent Overstreet Cc: Paul Moore Cc: Serge E. Hallyn Cc: Yafang Shao Cc: Matthew Wilcox (Oracle) Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- include/linux/security.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/security.h') diff --git a/include/linux/security.h b/include/linux/security.h index b86ec2afc691..2ec8f3014757 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -348,7 +348,7 @@ 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, @@ -789,7 +789,7 @@ 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; } -- cgit v1.2.3