From 66717260545b67b04ce6b004fff26de7141b2757 Mon Sep 17 00:00:00 2001 From: Elena Reshetova Date: Wed, 29 Nov 2017 13:19:31 +0200 Subject: posix_acl: convert posix_acl.a_refcount from atomic_t to refcount_t atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable posix_acl.a_refcount is used as pure reference counter. Convert it to refcount_t and fix up the operations. **Important note for maintainers: Some functions from refcount_t API defined in lib/refcount.c have different memory ordering guarantees than their atomic counterparts. The full comparison can be seen in https://lkml.org/lkml/2017/11/15/57 and it is hopefully soon in state to be merged to the documentation tree. Normally the differences should not matter since refcount_t provides enough guarantees to satisfy the refcounting use cases, but in some rare cases it might matter. Please double check that you don't have some undocumented memory guarantees for this variable usage. For the posix_acl.a_refcount it might make a difference in following places: - get_cached_acl(): increment in refcount_inc_not_zero() only guarantees control dependency on success vs. fully ordered atomic counterpart. However this operation is performed under rcu_read_lock(), so this should be fine. - posix_acl_release(): decrement in refcount_dec_and_test() only provides RELEASE ordering and control dependency on success vs. fully ordered atomic counterpart Suggested-by: Kees Cook Reviewed-by: David Windsor Reviewed-by: Hans Liljestrand Signed-off-by: Elena Reshetova Signed-off-by: Jaegeuk Kim --- include/linux/posix_acl.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h index b2b7255ec7f5..540595a321a7 100644 --- a/include/linux/posix_acl.h +++ b/include/linux/posix_acl.h @@ -12,6 +12,7 @@ #include #include #include +#include #include struct posix_acl_entry { @@ -24,7 +25,7 @@ struct posix_acl_entry { }; struct posix_acl { - atomic_t a_refcount; + refcount_t a_refcount; struct rcu_head a_rcu; unsigned int a_count; struct posix_acl_entry a_entries[0]; @@ -41,7 +42,7 @@ static inline struct posix_acl * posix_acl_dup(struct posix_acl *acl) { if (acl) - atomic_inc(&acl->a_refcount); + refcount_inc(&acl->a_refcount); return acl; } @@ -51,7 +52,7 @@ posix_acl_dup(struct posix_acl *acl) static inline void posix_acl_release(struct posix_acl *acl) { - if (acl && atomic_dec_and_test(&acl->a_refcount)) + if (acl && refcount_dec_and_test(&acl->a_refcount)) kfree_rcu(acl, a_rcu); } -- cgit v1.2.3 From 1ad71a27124caf0b68ddd3c92be01aa2b2a72b2a Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Thu, 7 Dec 2017 16:25:39 -0800 Subject: f2fs: add an ioctl to disable GC for specific file This patch gives a flag to disable GC on given file, which would be useful, when user wants to keep its block map. It also conducts in-place-update for dontmove file. Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- include/linux/f2fs_fs.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h index 43e98d30d2df..cfb522e6affc 100644 --- a/include/linux/f2fs_fs.h +++ b/include/linux/f2fs_fs.h @@ -212,6 +212,7 @@ struct f2fs_extent { #define F2FS_DATA_EXIST 0x08 /* file inline data exist flag */ #define F2FS_INLINE_DOTS 0x10 /* file having implicit dot dentries */ #define F2FS_EXTRA_ATTR 0x20 /* file having extra attribute */ +#define F2FS_PIN_FILE 0x40 /* file should not be gced */ struct f2fs_inode { __le16 i_mode; /* file mode */ @@ -229,7 +230,13 @@ struct f2fs_inode { __le32 i_ctime_nsec; /* change time in nano scale */ __le32 i_mtime_nsec; /* modification time in nano scale */ __le32 i_generation; /* file version (for NFS) */ - __le32 i_current_depth; /* only for directory depth */ + union { + __le32 i_current_depth; /* only for directory depth */ + __le16 i_gc_failures; /* + * # of gc failures on pinned file. + * only for regular files. + */ + }; __le32 i_xattr_nid; /* nid to save xattr */ __le32 i_flags; /* file attributes */ __le32 i_pino; /* parent inode number */ -- cgit v1.2.3 From f236792311f4575a1ca47240d3a74034096ef9e8 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Fri, 19 Jan 2018 13:42:33 -0800 Subject: f2fs: allow to recover node blocks given updated checkpoint If fsck.f2fs changes crc, we have no way to recover some inode blocks by roll- forward recovery. Let's relax the condition to recover them. Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- include/linux/f2fs_fs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h index cfb522e6affc..6eed677b6d9a 100644 --- a/include/linux/f2fs_fs.h +++ b/include/linux/f2fs_fs.h @@ -117,6 +117,7 @@ struct f2fs_super_block { /* * For checkpoint */ +#define CP_NOCRC_RECOVERY_FLAG 0x00000200 #define CP_TRIMMED_FLAG 0x00000100 #define CP_NAT_BITS_FLAG 0x00000080 #define CP_CRC_RECOVERY_FLAG 0x00000040 -- cgit v1.2.3 From 1c1d35df71104c76a4a2e25862926f22c334c9d6 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Thu, 25 Jan 2018 14:54:42 +0800 Subject: f2fs: support inode creation time This patch adds creation time field in inode layout to support showing kstat.btime in ->statx. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- include/linux/f2fs_fs.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h index 6eed677b6d9a..58aecb60ea51 100644 --- a/include/linux/f2fs_fs.h +++ b/include/linux/f2fs_fs.h @@ -253,8 +253,10 @@ struct f2fs_inode { __le16 i_inline_xattr_size; /* inline xattr size, unit: 4 bytes */ __le32 i_projid; /* project id */ __le32 i_inode_checksum;/* inode meta checksum */ + __le64 i_crtime; /* creation time */ + __le32 i_crtime_nsec; /* creation time in nano scale */ __le32 i_extra_end[0]; /* for attribute size calculation */ - }; + } __packed; __le32 i_addr[DEF_ADDRS_PER_INODE]; /* Pointers to data blocks */ }; __le32 i_nid[DEF_NIDS_PER_INODE]; /* direct(2), indirect(2), -- cgit v1.2.3