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path: root/fs/btrfs/props.h
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2022-05-16btrfs: move common inode creation code into btrfs_create_new_inode()Omar Sandoval1-4/+0
All of our inode creation code paths duplicate the calls to btrfs_init_inode_security() and btrfs_add_link(). Subvolume creation additionally duplicates property inheritance and the call to btrfs_set_inode_index(). Fix this by moving the common code into btrfs_create_new_inode(). This accomplishes a few things at once: 1. It reduces code duplication. 2. It allows us to set up the inode completely before inserting the inode item, removing calls to btrfs_update_inode(). 3. It fixes a leak of an inode on disk in some error cases. For example, in btrfs_create(), if btrfs_new_inode() succeeds, then we have inserted an inode item and its inode ref. However, if something after that fails (e.g., btrfs_init_inode_security()), then we end the transaction and then decrement the link count on the inode. If the transaction is committed and the system crashes before the failed inode is deleted, then we leak that inode on disk. Instead, this refactoring aborts the transaction when we can't recover more gracefully. 4. It exposes various ways that subvolume creation diverges from mkdir in terms of inheriting flags, properties, permissions, and POSIX ACLs, a lot of which appears to be accidental. This patch explicitly does _not_ change the existing non-standard behavior, but it makes those differences more clear in the code and documents them so that we can discuss whether they should be changed. Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-04-27btrfs: skip compression property for anything other than files and dirsFilipe Manana1-0/+1
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 <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-04-27btrfs: do not allow compression on nodatacow filesChung-Chiang Cheng1-1/+2
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 <jaycelin@synology.com> 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 <fdmanana@suse.com> Signed-off-by: Chung-Chiang Cheng <cccheng@synology.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29btrfs: delete unused function btrfs_set_prop_transAnand Jain1-2/+0
The last consumer of btrfs_set_prop_trans() was taken away by the patch ("btrfs: start transaction in xattr_handler_set_prop") so now this function can be deleted. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29btrfs: export btrfs_set_propAnand Jain1-0/+3
Make btrfs_set_prop() a non-static function, so that it can be called from btrfs_ioctl_setflags(). We need btrfs_set_prop() instead of btrfs_set_prop_trans() so that we can use the transaction which is already started in the current thread. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29btrfs: refactor btrfs_set_props to validate externallyAnand Jain1-0/+1
In preparation to merge multiple transactions when setting the compression flags, split btrfs_set_props() validation part outside of it. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29btrfs: refactor btrfs_set_prop and add btrfs_set_prop_transAnand Jain1-3/+2
btrfs_set_prop() takes transaction pointer as the first argument, however in ioctl.c for the purpose of setting the compression property, we call btrfs_set_prop() with NULL transaction pointer. Down in the call chain btrfs_setxattr() starts transaction to update the attribute and also to update the inode. So for clarity, create btrfs_set_prop_trans() with no transaction pointer as argument, in preparation to start transaction here instead of doing it down the call chain at btrfs_setxattr(). Also now the btrfs_set_prop() is a static function. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29btrfs: merge _btrfs_set_prop helpersAnand Jain1-4/+2
btrfs_set_prop() is a redirect to __btrfs_set_prop() with the transaction handle equal to NULL. __btrfs_set_prop() in turn passes this to do_setxattr() which then transaction is actually created. Instead merge __btrfs_set_prop() to btrfs_set_prop(), and update the caller with NULL argument. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-04-12btrfs: replace GPL boilerplate by SPDX -- headersDavid Sterba1-16/+3
Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Unify the include protection macros to match the file names. Signed-off-by: David Sterba <dsterba@suse.com>
2014-01-29Btrfs: add support for inode propertiesFilipe David Borba Manana1-0/+42
This change adds infrastructure to allow for generic properties for inodes. Properties are name/value pairs that can be associated with inodes for different purposes. They are stored as xattrs with the prefix "btrfs." Properties can be inherited - this means when a directory inode has inheritable properties set, these are added to new inodes created under that directory. Further, subvolumes can also have properties associated with them, and they can be inherited from their parent subvolume. Naturally, directory properties have priority over subvolume properties (in practice a subvolume property is just a regular property associated with the root inode, objectid 256, of the subvolume's fs tree). This change also adds one specific property implementation, named "compression", whose values can be "lzo" or "zlib" and it's an inheritable property. The corresponding changes to btrfs-progs were also implemented. A patch with xfstests for this feature will follow once there's agreement on this change/feature. Further, the script at the bottom of this commit message was used to do some benchmarks to measure any performance penalties of this feature. Basically the tests correspond to: Test 1 - create a filesystem and mount it with compress-force=lzo, then sequentially create N files of 64Kb each, measure how long it took to create the files, unmount the filesystem, mount the filesystem and perform an 'ls -lha' against the test directory holding the N files, and report the time the command took. Test 2 - create a filesystem and don't use any compression option when mounting it - instead set the compression property of the subvolume's root to 'lzo'. Then create N files of 64Kb, and report the time it took. The unmount the filesystem, mount it again and perform an 'ls -lha' like in the former test. This means every single file ends up with a property (xattr) associated to it. Test 3 - same as test 2, but uses 4 properties - 3 are duplicates of the compression property, have no real effect other than adding more work when inheriting properties and taking more btree leaf space. Test 4 - same as test 3 but with 10 properties per file. Results (in seconds, and averages of 5 runs each), for different N numbers of files follow. * Without properties (test 1) file creation time ls -lha time 10 000 files 3.49 0.76 100 000 files 47.19 8.37 1 000 000 files 518.51 107.06 * With 1 property (compression property set to lzo - test 2) file creation time ls -lha time 10 000 files 3.63 0.93 100 000 files 48.56 9.74 1 000 000 files 537.72 125.11 * With 4 properties (test 3) file creation time ls -lha time 10 000 files 3.94 1.20 100 000 files 52.14 11.48 1 000 000 files 572.70 142.13 * With 10 properties (test 4) file creation time ls -lha time 10 000 files 4.61 1.35 100 000 files 58.86 13.83 1 000 000 files 656.01 177.61 The increased latencies with properties are essencialy because of: *) When creating an inode, we now synchronously write 1 more item (an xattr item) for each property inherited from the parent dir (or subvolume). This could be done in an asynchronous way such as we do for dir intex items (delayed-inode.c), which could help reduce the file creation latency; *) With properties, we now have larger fs trees. For this particular test each xattr item uses 75 bytes of leaf space in the fs tree. This could be less by using a new item for xattr items, instead of the current btrfs_dir_item, since we could cut the 'location' and 'type' fields (saving 18 bytes) and maybe 'transid' too (saving a total of 26 bytes per xattr item) from the btrfs_dir_item type. Also tried batching the xattr insertions (ignoring proper hash collision handling, since it didn't exist) when creating files that inherit properties from their parent inode/subvolume, but the end results were (surprisingly) essentially the same. Test script: $ cat test.pl #!/usr/bin/perl -w use strict; use Time::HiRes qw(time); use constant NUM_FILES => 10_000; use constant FILE_SIZES => (64 * 1024); use constant DEV => '/dev/sdb4'; use constant MNT_POINT => '/home/fdmanana/btrfs-tests/dev'; use constant TEST_DIR => (MNT_POINT . '/testdir'); system("mkfs.btrfs", "-l", "16384", "-f", DEV) == 0 or die "mkfs.btrfs failed!"; # following line for testing without properties #system("mount", "-o", "compress-force=lzo", DEV, MNT_POINT) == 0 or die "mount failed!"; # following 2 lines for testing with properties system("mount", DEV, MNT_POINT) == 0 or die "mount failed!"; system("btrfs", "prop", "set", MNT_POINT, "compression", "lzo") == 0 or die "set prop failed!"; system("mkdir", TEST_DIR) == 0 or die "mkdir failed!"; my ($t1, $t2); $t1 = time(); for (my $i = 1; $i <= NUM_FILES; $i++) { my $p = TEST_DIR . '/file_' . $i; open(my $f, '>', $p) or die "Error opening file!"; $f->autoflush(1); for (my $j = 0; $j < FILE_SIZES; $j += 4096) { print $f ('A' x 4096) or die "Error writing to file!"; } close($f); } $t2 = time(); print "Time to create " . NUM_FILES . ": " . ($t2 - $t1) . " seconds.\n"; system("umount", DEV) == 0 or die "umount failed!"; system("mount", DEV, MNT_POINT) == 0 or die "mount failed!"; $t1 = time(); system("bash -c 'ls -lha " . TEST_DIR . " > /dev/null'") == 0 or die "ls failed!"; $t2 = time(); print "Time to ls -lha all files: " . ($t2 - $t1) . " seconds.\n"; system("umount", DEV) == 0 or die "umount failed!"; Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>