From 0e852ab8974cd2b5946766b2d9baf82c78ace03d Mon Sep 17 00:00:00 2001 From: Chung-Chiang Cheng Date: Fri, 15 Apr 2022 16:04:06 +0800 Subject: btrfs: do not allow compression on nodatacow files Compression and nodatacow are mutually exclusive. A similar issue was fixed by commit f37c563bab429 ("btrfs: add missing check for nocow and compression inode flags"). Besides ioctl, there is another way to enable/disable/reset compression directly via xattr. The following steps will result in a invalid combination. $ touch bar $ chattr +C bar $ lsattr bar ---------------C-- bar $ setfattr -n btrfs.compression -v zstd bar $ lsattr bar --------c------C-- bar To align with the logic in check_fsflags, nocompress will also be unacceptable after this patch, to prevent mix any compression-related options with nodatacow. $ touch bar $ chattr +C bar $ lsattr bar ---------------C-- bar $ setfattr -n btrfs.compression -v zstd bar setfattr: bar: Invalid argument $ setfattr -n btrfs.compression -v no bar setfattr: bar: Invalid argument When both compression and nodatacow are enabled, then btrfs_run_delalloc_range prefers nodatacow and no compression happens. Reported-by: Jayce Lin CC: stable@vger.kernel.org # 5.10.x: e6f9d6964802: btrfs: export a helper for compression hard check CC: stable@vger.kernel.org # 5.10.x Reviewed-by: Filipe Manana Signed-off-by: Chung-Chiang Cheng Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/props.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) (limited to 'fs/btrfs/props.c') diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c index 1a6d2d5b4b33..5a6f87744c28 100644 --- a/fs/btrfs/props.c +++ b/fs/btrfs/props.c @@ -17,7 +17,8 @@ static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS); struct prop_handler { struct hlist_node node; const char *xattr_name; - int (*validate)(const char *value, size_t len); + int (*validate)(const struct btrfs_inode *inode, const char *value, + size_t len); int (*apply)(struct inode *inode, const char *value, size_t len); const char *(*extract)(struct inode *inode); int inheritable; @@ -55,7 +56,8 @@ find_prop_handler(const char *name, return NULL; } -int btrfs_validate_prop(const char *name, const char *value, size_t value_len) +int btrfs_validate_prop(const struct btrfs_inode *inode, const char *name, + const char *value, size_t value_len) { const struct prop_handler *handler; @@ -69,7 +71,7 @@ int btrfs_validate_prop(const char *name, const char *value, size_t value_len) if (value_len == 0) return 0; - return handler->validate(value, value_len); + return handler->validate(inode, value, value_len); } int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode, @@ -252,8 +254,12 @@ int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path) return ret; } -static int prop_compression_validate(const char *value, size_t len) +static int prop_compression_validate(const struct btrfs_inode *inode, + const char *value, size_t len) { + if (!btrfs_inode_can_compress(inode)) + return -EINVAL; + if (!value) return 0; @@ -364,7 +370,7 @@ static int inherit_props(struct btrfs_trans_handle *trans, * This is not strictly necessary as the property should be * valid, but in case it isn't, don't propagate it further. */ - ret = h->validate(value, strlen(value)); + ret = h->validate(BTRFS_I(inode), value, strlen(value)); if (ret) continue; -- cgit v1.2.3 From 4b73c55fdebd8939f0f6000921075f7f6fa41397 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Thu, 21 Apr 2022 11:01:22 +0100 Subject: btrfs: skip compression property for anything other than files and dirs The compression property only has effect on regular files and directories (so that it's propagated to files and subdirectories created inside a directory). For any other inode type (symlink, fifo, device, socket), it's pointless to set the compression property because it does nothing and ends up unnecessarily wasting leaf space due to the pointless xattr (75 or 76 bytes, depending on the compression value). Symlinks in particular are very common (for example, I have almost 10k symlinks under /etc, /usr and /var alone) and therefore it's worth to avoid wasting leaf space with the compression xattr. For example, the compression property can end up on a symlink or character device implicitly, through inheritance from a parent directory $ mkdir /mnt/testdir $ btrfs property set /mnt/testdir compression lzo $ ln -s yadayada /mnt/testdir/lnk $ mknod /mnt/testdir/dev c 0 0 Or explicitly like this: $ ln -s yadayda /mnt/lnk $ setfattr -h -n btrfs.compression -v lzo /mnt/lnk So skip the compression property on inodes that are neither a regular file nor a directory. CC: stable@vger.kernel.org # 5.4+ Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/props.c | 43 +++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/props.h | 1 + fs/btrfs/xattr.c | 3 +++ 3 files changed, 47 insertions(+) (limited to 'fs/btrfs/props.c') diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c index 5a6f87744c28..1b31481f9e72 100644 --- a/fs/btrfs/props.c +++ b/fs/btrfs/props.c @@ -21,6 +21,7 @@ struct prop_handler { size_t len); int (*apply)(struct inode *inode, const char *value, size_t len); const char *(*extract)(struct inode *inode); + bool (*ignore)(const struct btrfs_inode *inode); int inheritable; }; @@ -74,6 +75,28 @@ int btrfs_validate_prop(const struct btrfs_inode *inode, const char *name, return handler->validate(inode, value, value_len); } +/* + * Check if a property should be ignored (not set) for an inode. + * + * @inode: The target inode. + * @name: The property's name. + * + * The caller must be sure the given property name is valid, for example by + * having previously called btrfs_validate_prop(). + * + * Returns: true if the property should be ignored for the given inode + * false if the property must not be ignored for the given inode + */ +bool btrfs_ignore_prop(const struct btrfs_inode *inode, const char *name) +{ + const struct prop_handler *handler; + + handler = find_prop_handler(name, NULL); + ASSERT(handler != NULL); + + return handler->ignore(inode); +} + int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode, const char *name, const char *value, size_t value_len, int flags) @@ -316,6 +339,22 @@ static int prop_compression_apply(struct inode *inode, const char *value, return 0; } +static bool prop_compression_ignore(const struct btrfs_inode *inode) +{ + /* + * Compression only has effect for regular files, and for directories + * we set it just to propagate it to new files created inside them. + * Everything else (symlinks, devices, sockets, fifos) is pointless as + * it will do nothing, so don't waste metadata space on a compression + * xattr for anything that is neither a file nor a directory. + */ + if (!S_ISREG(inode->vfs_inode.i_mode) && + !S_ISDIR(inode->vfs_inode.i_mode)) + return true; + + return false; +} + static const char *prop_compression_extract(struct inode *inode) { switch (BTRFS_I(inode)->prop_compress) { @@ -336,6 +375,7 @@ static struct prop_handler prop_handlers[] = { .validate = prop_compression_validate, .apply = prop_compression_apply, .extract = prop_compression_extract, + .ignore = prop_compression_ignore, .inheritable = 1 }, }; @@ -362,6 +402,9 @@ static int inherit_props(struct btrfs_trans_handle *trans, if (!h->inheritable) continue; + if (h->ignore(BTRFS_I(inode))) + continue; + value = h->extract(parent); if (!value) continue; diff --git a/fs/btrfs/props.h b/fs/btrfs/props.h index 2b2ac15ab788..59bea741cfcf 100644 --- a/fs/btrfs/props.h +++ b/fs/btrfs/props.h @@ -15,6 +15,7 @@ int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode, int flags); int btrfs_validate_prop(const struct btrfs_inode *inode, const char *name, const char *value, size_t value_len); +bool btrfs_ignore_prop(const struct btrfs_inode *inode, const char *name); int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path); diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c index 367bb87b66df..85691dc2232f 100644 --- a/fs/btrfs/xattr.c +++ b/fs/btrfs/xattr.c @@ -408,6 +408,9 @@ static int btrfs_xattr_handler_set_prop(const struct xattr_handler *handler, if (ret) return ret; + if (btrfs_ignore_prop(BTRFS_I(inode), name)) + return 0; + trans = btrfs_start_transaction(root, 2); if (IS_ERR(trans)) return PTR_ERR(trans); -- cgit v1.2.3