| Message ID | 7fd3068c977de9dd25eb98fa2b9d3cd928613138.1617900170.git.boris@bur.io (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: support fsverity | expand |
On 09/04/2021 02:33, Boris Burkov wrote: > The tree checker currently rejects unrecognized flags when it reads > btrfs_inode_item. Practically, this means that adding a new flag makes > the change backwards incompatible if the flag is ever set on a file. > Take up one of the 4 reserved u64 fields in the btrfs_inode_item as a > new "compat_flags". These flags are zero on inode creation in btrfs and > mkfs and are ignored by an older kernel, so it should be safe to use > them in this way. I don't see an incompt flags check during mount, how does this patch will handle if you mount a disk with an older on-disk btrfs_inode_item data structure which has no compat_flags? Why not update the tree checker (need to fix stable kernel as well) and inode flags, so that we spare u64 space in the btrfs_inode_item? Also, I think we need the incompt flags to check during mount. Thanks, Anand > Signed-off-by: Boris Burkov <boris@bur.io> > --- > fs/btrfs/btrfs_inode.h | 1 + > fs/btrfs/ctree.h | 2 ++ > fs/btrfs/delayed-inode.c | 2 ++ > fs/btrfs/inode.c | 3 +++ > fs/btrfs/ioctl.c | 7 ++++--- > fs/btrfs/tree-log.c | 1 + > include/uapi/linux/btrfs_tree.h | 7 ++++++- > 7 files changed, 19 insertions(+), 4 deletions(-) > > diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h > index c652e19ad74e..e8dbc8e848ce 100644 > --- a/fs/btrfs/btrfs_inode.h > +++ b/fs/btrfs/btrfs_inode.h > @@ -191,6 +191,7 @@ struct btrfs_inode { > > /* flags field from the on disk inode */ > u32 flags; > + u64 compat_flags; > > /* > * Counters to keep track of the number of extent item's we may use due > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h > index f2fd73e58ee6..d633c563164b 100644 > --- a/fs/btrfs/ctree.h > +++ b/fs/btrfs/ctree.h > @@ -1754,6 +1754,7 @@ BTRFS_SETGET_FUNCS(inode_gid, struct btrfs_inode_item, gid, 32); > BTRFS_SETGET_FUNCS(inode_mode, struct btrfs_inode_item, mode, 32); > BTRFS_SETGET_FUNCS(inode_rdev, struct btrfs_inode_item, rdev, 64); > BTRFS_SETGET_FUNCS(inode_flags, struct btrfs_inode_item, flags, 64); > +BTRFS_SETGET_FUNCS(inode_compat_flags, struct btrfs_inode_item, compat_flags, 64); > BTRFS_SETGET_STACK_FUNCS(stack_inode_generation, struct btrfs_inode_item, > generation, 64); > BTRFS_SETGET_STACK_FUNCS(stack_inode_sequence, struct btrfs_inode_item, > @@ -1771,6 +1772,7 @@ BTRFS_SETGET_STACK_FUNCS(stack_inode_gid, struct btrfs_inode_item, gid, 32); > BTRFS_SETGET_STACK_FUNCS(stack_inode_mode, struct btrfs_inode_item, mode, 32); > BTRFS_SETGET_STACK_FUNCS(stack_inode_rdev, struct btrfs_inode_item, rdev, 64); > BTRFS_SETGET_STACK_FUNCS(stack_inode_flags, struct btrfs_inode_item, flags, 64); > +BTRFS_SETGET_STACK_FUNCS(stack_inode_compat_flags, struct btrfs_inode_item, compat_flags, 64); > BTRFS_SETGET_FUNCS(timespec_sec, struct btrfs_timespec, sec, 64); > BTRFS_SETGET_FUNCS(timespec_nsec, struct btrfs_timespec, nsec, 32); > BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec, sec, 64); > diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c > index 1a88f6214ebc..ef4e0265dbe3 100644 > --- a/fs/btrfs/delayed-inode.c > +++ b/fs/btrfs/delayed-inode.c > @@ -1718,6 +1718,7 @@ static void fill_stack_inode_item(struct btrfs_trans_handle *trans, > btrfs_set_stack_inode_transid(inode_item, trans->transid); > btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev); > btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags); > + btrfs_set_stack_inode_compat_flags(inode_item, BTRFS_I(inode)->compat_flags); > btrfs_set_stack_inode_block_group(inode_item, 0); > > btrfs_set_stack_timespec_sec(&inode_item->atime, > @@ -1776,6 +1777,7 @@ int btrfs_fill_inode(struct inode *inode, u32 *rdev) > inode->i_rdev = 0; > *rdev = btrfs_stack_inode_rdev(inode_item); > BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item); > + BTRFS_I(inode)->compat_flags = btrfs_stack_inode_compat_flags(inode_item); > > inode->i_atime.tv_sec = btrfs_stack_timespec_sec(&inode_item->atime); > inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->atime); > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 1e0e20ad25e4..3aa96ec27045 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -3627,6 +3627,7 @@ static int btrfs_read_locked_inode(struct inode *inode, > > BTRFS_I(inode)->index_cnt = (u64)-1; > BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); > + BTRFS_I(inode)->compat_flags = btrfs_inode_compat_flags(leaf, inode_item); > > cache_index: > /* > @@ -3793,6 +3794,7 @@ static void fill_inode_item(struct btrfs_trans_handle *trans, > btrfs_set_token_inode_transid(&token, item, trans->transid); > btrfs_set_token_inode_rdev(&token, item, inode->i_rdev); > btrfs_set_token_inode_flags(&token, item, BTRFS_I(inode)->flags); > + btrfs_set_token_inode_compat_flags(&token, item, BTRFS_I(inode)->compat_flags); > btrfs_set_token_inode_block_group(&token, item, 0); > } > > @@ -8859,6 +8861,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) > ei->defrag_bytes = 0; > ei->disk_i_size = 0; > ei->flags = 0; > + ei->compat_flags = 0; > ei->csum_bytes = 0; > ei->index_cnt = (u64)-1; > ei->dir_index = 0; > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index 3415a9f06c81..2c9cbd2642b1 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -102,8 +102,9 @@ static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode, > * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS > * ioctl. > */ > -static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags) > +static unsigned int btrfs_inode_flags_to_fsflags(struct btrfs_inode *binode) > { > + unsigned int flags = binode->flags; > unsigned int iflags = 0; > > if (flags & BTRFS_INODE_SYNC) > @@ -156,7 +157,7 @@ void btrfs_sync_inode_flags_to_i_flags(struct inode *inode) > static int btrfs_ioctl_getflags(struct file *file, void __user *arg) > { > struct btrfs_inode *binode = BTRFS_I(file_inode(file)); > - unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags); > + unsigned int flags = btrfs_inode_flags_to_fsflags(binode); > > if (copy_to_user(arg, &flags, sizeof(flags))) > return -EFAULT; > @@ -228,7 +229,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) > > btrfs_inode_lock(inode, 0); > fsflags = btrfs_mask_fsflags_for_type(inode, fsflags); > - old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags); > + old_fsflags = btrfs_inode_flags_to_fsflags(binode); > > ret = vfs_ioc_setflags_prepare(inode, old_fsflags, fsflags); > if (ret) > diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c > index 72c4b66ed516..fed638f995ba 100644 > --- a/fs/btrfs/tree-log.c > +++ b/fs/btrfs/tree-log.c > @@ -3944,6 +3944,7 @@ static void fill_inode_item(struct btrfs_trans_handle *trans, > btrfs_set_token_inode_transid(&token, item, trans->transid); > btrfs_set_token_inode_rdev(&token, item, inode->i_rdev); > btrfs_set_token_inode_flags(&token, item, BTRFS_I(inode)->flags); > + btrfs_set_token_inode_compat_flags(&token, item, BTRFS_I(inode)->compat_flags); > btrfs_set_token_inode_block_group(&token, item, 0); > } > > diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h > index 58d7cff9afb1..ae25280316bd 100644 > --- a/include/uapi/linux/btrfs_tree.h > +++ b/include/uapi/linux/btrfs_tree.h > @@ -574,11 +574,16 @@ struct btrfs_inode_item { > /* modification sequence number for NFS */ > __le64 sequence; > > + /* > + * flags which aren't checked for corruption at mount > + * and can be added in a backwards compatible way > + */ > + __le64 compat_flags; > /* > * a little future expansion, for more than this we can > * just grow the inode item and version it > */ > - __le64 reserved[4]; > + __le64 reserved[3]; > struct btrfs_timespec atime; > struct btrfs_timespec ctime; > struct btrfs_timespec mtime; >
On Fri, Apr 09, 2021 at 07:40:44AM +0800, Anand Jain wrote: > On 09/04/2021 02:33, Boris Burkov wrote: > > The tree checker currently rejects unrecognized flags when it reads > > btrfs_inode_item. Practically, this means that adding a new flag makes > > the change backwards incompatible if the flag is ever set on a file. > > > > Take up one of the 4 reserved u64 fields in the btrfs_inode_item as a > > new "compat_flags". These flags are zero on inode creation in btrfs and > > mkfs and are ignored by an older kernel, so it should be safe to use > > them in this way. > > I don't see an incompt flags check during mount, how does this patch will > handle if you mount a disk with an older on-disk btrfs_inode_item data > structure which has no compat_flags? I'm referring to check_inode_item in fs/btrfs/tree-checker.c Specificall, the last check it does that fails with the string: "unknown flags detected". This patch ignores the new compat_flags from a checking perspective, so it won't complain no matter what an old on-disk format put there. As far as I can tell from inspecting the code and mkfs, it should be zero, though I suppose it's possible an older version of btrfs did not zero it. I think the worst case would be if it weren't zero and we incorrectly interpreted the file as having a compat_flags flag set. > > Why not update the tree checker (need to fix stable kernel as well) and > inode flags, so that we spare u64 space in the btrfs_inode_item? I don't understand this suggestion, could you be more specific? > > Also, I think we need the incompt flags to check during mount. Same for this one, sorry. What do you think I should check? > > Thanks, Anand Thank you for the review, Boris > > > > Signed-off-by: Boris Burkov <boris@bur.io> > > --- > > fs/btrfs/btrfs_inode.h | 1 + > > fs/btrfs/ctree.h | 2 ++ > > fs/btrfs/delayed-inode.c | 2 ++ > > fs/btrfs/inode.c | 3 +++ > > fs/btrfs/ioctl.c | 7 ++++--- > > fs/btrfs/tree-log.c | 1 + > > include/uapi/linux/btrfs_tree.h | 7 ++++++- > > 7 files changed, 19 insertions(+), 4 deletions(-) > > > > diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h > > index c652e19ad74e..e8dbc8e848ce 100644 > > --- a/fs/btrfs/btrfs_inode.h > > +++ b/fs/btrfs/btrfs_inode.h > > @@ -191,6 +191,7 @@ struct btrfs_inode { > > /* flags field from the on disk inode */ > > u32 flags; > > + u64 compat_flags; > > /* > > * Counters to keep track of the number of extent item's we may use due > > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h > > index f2fd73e58ee6..d633c563164b 100644 > > --- a/fs/btrfs/ctree.h > > +++ b/fs/btrfs/ctree.h > > @@ -1754,6 +1754,7 @@ BTRFS_SETGET_FUNCS(inode_gid, struct btrfs_inode_item, gid, 32); > > BTRFS_SETGET_FUNCS(inode_mode, struct btrfs_inode_item, mode, 32); > > BTRFS_SETGET_FUNCS(inode_rdev, struct btrfs_inode_item, rdev, 64); > > BTRFS_SETGET_FUNCS(inode_flags, struct btrfs_inode_item, flags, 64); > > +BTRFS_SETGET_FUNCS(inode_compat_flags, struct btrfs_inode_item, compat_flags, 64); > > BTRFS_SETGET_STACK_FUNCS(stack_inode_generation, struct btrfs_inode_item, > > generation, 64); > > BTRFS_SETGET_STACK_FUNCS(stack_inode_sequence, struct btrfs_inode_item, > > @@ -1771,6 +1772,7 @@ BTRFS_SETGET_STACK_FUNCS(stack_inode_gid, struct btrfs_inode_item, gid, 32); > > BTRFS_SETGET_STACK_FUNCS(stack_inode_mode, struct btrfs_inode_item, mode, 32); > > BTRFS_SETGET_STACK_FUNCS(stack_inode_rdev, struct btrfs_inode_item, rdev, 64); > > BTRFS_SETGET_STACK_FUNCS(stack_inode_flags, struct btrfs_inode_item, flags, 64); > > +BTRFS_SETGET_STACK_FUNCS(stack_inode_compat_flags, struct btrfs_inode_item, compat_flags, 64); > > BTRFS_SETGET_FUNCS(timespec_sec, struct btrfs_timespec, sec, 64); > > BTRFS_SETGET_FUNCS(timespec_nsec, struct btrfs_timespec, nsec, 32); > > BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec, sec, 64); > > diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c > > index 1a88f6214ebc..ef4e0265dbe3 100644 > > --- a/fs/btrfs/delayed-inode.c > > +++ b/fs/btrfs/delayed-inode.c > > @@ -1718,6 +1718,7 @@ static void fill_stack_inode_item(struct btrfs_trans_handle *trans, > > btrfs_set_stack_inode_transid(inode_item, trans->transid); > > btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev); > > btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags); > > + btrfs_set_stack_inode_compat_flags(inode_item, BTRFS_I(inode)->compat_flags); > > btrfs_set_stack_inode_block_group(inode_item, 0); > > btrfs_set_stack_timespec_sec(&inode_item->atime, > > @@ -1776,6 +1777,7 @@ int btrfs_fill_inode(struct inode *inode, u32 *rdev) > > inode->i_rdev = 0; > > *rdev = btrfs_stack_inode_rdev(inode_item); > > BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item); > > + BTRFS_I(inode)->compat_flags = btrfs_stack_inode_compat_flags(inode_item); > > inode->i_atime.tv_sec = btrfs_stack_timespec_sec(&inode_item->atime); > > inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->atime); > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > > index 1e0e20ad25e4..3aa96ec27045 100644 > > --- a/fs/btrfs/inode.c > > +++ b/fs/btrfs/inode.c > > @@ -3627,6 +3627,7 @@ static int btrfs_read_locked_inode(struct inode *inode, > > BTRFS_I(inode)->index_cnt = (u64)-1; > > BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); > > + BTRFS_I(inode)->compat_flags = btrfs_inode_compat_flags(leaf, inode_item); > > cache_index: > > /* > > @@ -3793,6 +3794,7 @@ static void fill_inode_item(struct btrfs_trans_handle *trans, > > btrfs_set_token_inode_transid(&token, item, trans->transid); > > btrfs_set_token_inode_rdev(&token, item, inode->i_rdev); > > btrfs_set_token_inode_flags(&token, item, BTRFS_I(inode)->flags); > > + btrfs_set_token_inode_compat_flags(&token, item, BTRFS_I(inode)->compat_flags); > > btrfs_set_token_inode_block_group(&token, item, 0); > > } > > @@ -8859,6 +8861,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) > > ei->defrag_bytes = 0; > > ei->disk_i_size = 0; > > ei->flags = 0; > > + ei->compat_flags = 0; > > ei->csum_bytes = 0; > > ei->index_cnt = (u64)-1; > > ei->dir_index = 0; > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > > index 3415a9f06c81..2c9cbd2642b1 100644 > > --- a/fs/btrfs/ioctl.c > > +++ b/fs/btrfs/ioctl.c > > @@ -102,8 +102,9 @@ static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode, > > * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS > > * ioctl. > > */ > > -static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags) > > +static unsigned int btrfs_inode_flags_to_fsflags(struct btrfs_inode *binode) > > { > > + unsigned int flags = binode->flags; > > unsigned int iflags = 0; > > if (flags & BTRFS_INODE_SYNC) > > @@ -156,7 +157,7 @@ void btrfs_sync_inode_flags_to_i_flags(struct inode *inode) > > static int btrfs_ioctl_getflags(struct file *file, void __user *arg) > > { > > struct btrfs_inode *binode = BTRFS_I(file_inode(file)); > > - unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags); > > + unsigned int flags = btrfs_inode_flags_to_fsflags(binode); > > if (copy_to_user(arg, &flags, sizeof(flags))) > > return -EFAULT; > > @@ -228,7 +229,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) > > btrfs_inode_lock(inode, 0); > > fsflags = btrfs_mask_fsflags_for_type(inode, fsflags); > > - old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags); > > + old_fsflags = btrfs_inode_flags_to_fsflags(binode); > > ret = vfs_ioc_setflags_prepare(inode, old_fsflags, fsflags); > > if (ret) > > diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c > > index 72c4b66ed516..fed638f995ba 100644 > > --- a/fs/btrfs/tree-log.c > > +++ b/fs/btrfs/tree-log.c > > @@ -3944,6 +3944,7 @@ static void fill_inode_item(struct btrfs_trans_handle *trans, > > btrfs_set_token_inode_transid(&token, item, trans->transid); > > btrfs_set_token_inode_rdev(&token, item, inode->i_rdev); > > btrfs_set_token_inode_flags(&token, item, BTRFS_I(inode)->flags); > > + btrfs_set_token_inode_compat_flags(&token, item, BTRFS_I(inode)->compat_flags); > > btrfs_set_token_inode_block_group(&token, item, 0); > > } > > diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h > > index 58d7cff9afb1..ae25280316bd 100644 > > --- a/include/uapi/linux/btrfs_tree.h > > +++ b/include/uapi/linux/btrfs_tree.h > > @@ -574,11 +574,16 @@ struct btrfs_inode_item { > > /* modification sequence number for NFS */ > > __le64 sequence; > > + /* > > + * flags which aren't checked for corruption at mount > > + * and can be added in a backwards compatible way > > + */ > > + __le64 compat_flags; > > /* > > * a little future expansion, for more than this we can > > * just grow the inode item and version it > > */ > > - __le64 reserved[4]; > > + __le64 reserved[3]; > > struct btrfs_timespec atime; > > struct btrfs_timespec ctime; > > struct btrfs_timespec mtime; > > >
On Fri, Apr 09, 2021 at 11:20:32AM -0700, Boris Burkov wrote: > On Fri, Apr 09, 2021 at 07:40:44AM +0800, Anand Jain wrote: > > On 09/04/2021 02:33, Boris Burkov wrote: > > Why not update the tree checker (need to fix stable kernel as well) and > > inode flags, so that we spare u64 space in the btrfs_inode_item? > > I don't understand this suggestion, could you be more specific? That's probably the same suggestion I made regarding the existing inode flags split, with some minimal backport to recognize the compat flags. > > Also, I think we need the incompt flags to check during mount. > > Same for this one, sorry. What do you think I should check? The flag is read-only compat, and once it's added to the set BTRFS_FEATURE_COMPAT_RO_SUPP it's already checked in open_ctree 3290 /* 3291 * Needn't use the lock because there is no other task which will 3292 * update the flag. 3293 */ 3294 btrfs_set_super_incompat_flags(disk_super, features); 3295 3296 features = btrfs_super_compat_ro_flags(disk_super) & 3297 ~BTRFS_FEATURE_COMPAT_RO_SUPP; 3298 if (!sb_rdonly(sb) && features) { 3299 btrfs_err(fs_info, 3300 "cannot mount read-write because of unsupported optional features (%llx)", 3301 features); 3302 err = -EINVAL; 3303 goto fail_alloc; 3304 } So the mount check is there.
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index c652e19ad74e..e8dbc8e848ce 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -191,6 +191,7 @@ struct btrfs_inode { /* flags field from the on disk inode */ u32 flags; + u64 compat_flags; /* * Counters to keep track of the number of extent item's we may use due diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index f2fd73e58ee6..d633c563164b 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1754,6 +1754,7 @@ BTRFS_SETGET_FUNCS(inode_gid, struct btrfs_inode_item, gid, 32); BTRFS_SETGET_FUNCS(inode_mode, struct btrfs_inode_item, mode, 32); BTRFS_SETGET_FUNCS(inode_rdev, struct btrfs_inode_item, rdev, 64); BTRFS_SETGET_FUNCS(inode_flags, struct btrfs_inode_item, flags, 64); +BTRFS_SETGET_FUNCS(inode_compat_flags, struct btrfs_inode_item, compat_flags, 64); BTRFS_SETGET_STACK_FUNCS(stack_inode_generation, struct btrfs_inode_item, generation, 64); BTRFS_SETGET_STACK_FUNCS(stack_inode_sequence, struct btrfs_inode_item, @@ -1771,6 +1772,7 @@ BTRFS_SETGET_STACK_FUNCS(stack_inode_gid, struct btrfs_inode_item, gid, 32); BTRFS_SETGET_STACK_FUNCS(stack_inode_mode, struct btrfs_inode_item, mode, 32); BTRFS_SETGET_STACK_FUNCS(stack_inode_rdev, struct btrfs_inode_item, rdev, 64); BTRFS_SETGET_STACK_FUNCS(stack_inode_flags, struct btrfs_inode_item, flags, 64); +BTRFS_SETGET_STACK_FUNCS(stack_inode_compat_flags, struct btrfs_inode_item, compat_flags, 64); BTRFS_SETGET_FUNCS(timespec_sec, struct btrfs_timespec, sec, 64); BTRFS_SETGET_FUNCS(timespec_nsec, struct btrfs_timespec, nsec, 32); BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec, sec, 64); diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c index 1a88f6214ebc..ef4e0265dbe3 100644 --- a/fs/btrfs/delayed-inode.c +++ b/fs/btrfs/delayed-inode.c @@ -1718,6 +1718,7 @@ static void fill_stack_inode_item(struct btrfs_trans_handle *trans, btrfs_set_stack_inode_transid(inode_item, trans->transid); btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev); btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags); + btrfs_set_stack_inode_compat_flags(inode_item, BTRFS_I(inode)->compat_flags); btrfs_set_stack_inode_block_group(inode_item, 0); btrfs_set_stack_timespec_sec(&inode_item->atime, @@ -1776,6 +1777,7 @@ int btrfs_fill_inode(struct inode *inode, u32 *rdev) inode->i_rdev = 0; *rdev = btrfs_stack_inode_rdev(inode_item); BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item); + BTRFS_I(inode)->compat_flags = btrfs_stack_inode_compat_flags(inode_item); inode->i_atime.tv_sec = btrfs_stack_timespec_sec(&inode_item->atime); inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->atime); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 1e0e20ad25e4..3aa96ec27045 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -3627,6 +3627,7 @@ static int btrfs_read_locked_inode(struct inode *inode, BTRFS_I(inode)->index_cnt = (u64)-1; BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); + BTRFS_I(inode)->compat_flags = btrfs_inode_compat_flags(leaf, inode_item); cache_index: /* @@ -3793,6 +3794,7 @@ static void fill_inode_item(struct btrfs_trans_handle *trans, btrfs_set_token_inode_transid(&token, item, trans->transid); btrfs_set_token_inode_rdev(&token, item, inode->i_rdev); btrfs_set_token_inode_flags(&token, item, BTRFS_I(inode)->flags); + btrfs_set_token_inode_compat_flags(&token, item, BTRFS_I(inode)->compat_flags); btrfs_set_token_inode_block_group(&token, item, 0); } @@ -8859,6 +8861,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) ei->defrag_bytes = 0; ei->disk_i_size = 0; ei->flags = 0; + ei->compat_flags = 0; ei->csum_bytes = 0; ei->index_cnt = (u64)-1; ei->dir_index = 0; diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 3415a9f06c81..2c9cbd2642b1 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -102,8 +102,9 @@ static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode, * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS * ioctl. */ -static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags) +static unsigned int btrfs_inode_flags_to_fsflags(struct btrfs_inode *binode) { + unsigned int flags = binode->flags; unsigned int iflags = 0; if (flags & BTRFS_INODE_SYNC) @@ -156,7 +157,7 @@ void btrfs_sync_inode_flags_to_i_flags(struct inode *inode) static int btrfs_ioctl_getflags(struct file *file, void __user *arg) { struct btrfs_inode *binode = BTRFS_I(file_inode(file)); - unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags); + unsigned int flags = btrfs_inode_flags_to_fsflags(binode); if (copy_to_user(arg, &flags, sizeof(flags))) return -EFAULT; @@ -228,7 +229,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) btrfs_inode_lock(inode, 0); fsflags = btrfs_mask_fsflags_for_type(inode, fsflags); - old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags); + old_fsflags = btrfs_inode_flags_to_fsflags(binode); ret = vfs_ioc_setflags_prepare(inode, old_fsflags, fsflags); if (ret) diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 72c4b66ed516..fed638f995ba 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -3944,6 +3944,7 @@ static void fill_inode_item(struct btrfs_trans_handle *trans, btrfs_set_token_inode_transid(&token, item, trans->transid); btrfs_set_token_inode_rdev(&token, item, inode->i_rdev); btrfs_set_token_inode_flags(&token, item, BTRFS_I(inode)->flags); + btrfs_set_token_inode_compat_flags(&token, item, BTRFS_I(inode)->compat_flags); btrfs_set_token_inode_block_group(&token, item, 0); } diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h index 58d7cff9afb1..ae25280316bd 100644 --- a/include/uapi/linux/btrfs_tree.h +++ b/include/uapi/linux/btrfs_tree.h @@ -574,11 +574,16 @@ struct btrfs_inode_item { /* modification sequence number for NFS */ __le64 sequence; + /* + * flags which aren't checked for corruption at mount + * and can be added in a backwards compatible way + */ + __le64 compat_flags; /* * a little future expansion, for more than this we can * just grow the inode item and version it */ - __le64 reserved[4]; + __le64 reserved[3]; struct btrfs_timespec atime; struct btrfs_timespec ctime; struct btrfs_timespec mtime;
The tree checker currently rejects unrecognized flags when it reads btrfs_inode_item. Practically, this means that adding a new flag makes the change backwards incompatible if the flag is ever set on a file. Take up one of the 4 reserved u64 fields in the btrfs_inode_item as a new "compat_flags". These flags are zero on inode creation in btrfs and mkfs and are ignored by an older kernel, so it should be safe to use them in this way. Signed-off-by: Boris Burkov <boris@bur.io> --- fs/btrfs/btrfs_inode.h | 1 + fs/btrfs/ctree.h | 2 ++ fs/btrfs/delayed-inode.c | 2 ++ fs/btrfs/inode.c | 3 +++ fs/btrfs/ioctl.c | 7 ++++--- fs/btrfs/tree-log.c | 1 + include/uapi/linux/btrfs_tree.h | 7 ++++++- 7 files changed, 19 insertions(+), 4 deletions(-)