btrfs-progs: docs: separate filesystem limits chapter

For section 5 and Administration.

Signed-off-by: David Sterba <dsterba@suse.com>

Documentation/Administration.rst

@@ -13,3 +13,8 @@ Bootloaders
 -----------
 
 .. include:: ch-bootloaders.rst
+
+Filesystem limits
+-----------------
+
+.. include:: ch-fs-limits.rst

Documentation/btrfs-man5.rst

@@ -221,40 +221,7 @@ for the balance to finish.
 FILESYSTEM LIMITS
 -----------------
 
-maximum file name length
-        255
-
-maximum symlink target length
-        depends on the *nodesize* value, for 4KiB it's 3949 bytes, for larger nodesize
-        it's 4095 due to the system limit PATH_MAX
-
-        The symlink target may not be a valid path, ie. the path name components
-        can exceed the limits (NAME_MAX), there's no content validation at ``symlink(3)``
-        creation.
-
-maximum number of inodes
-        2^64^ but depends on the available metadata space as the inodes are created
-        dynamically
-
-inode numbers
-        minimum number: 256 (for subvolumes), regular files and directories: 257
-
-maximum file length
-        inherent limit of btrfs is 2^64^ (16 EiB) but the linux VFS limit is 2^63^ (8 EiB)
-
-maximum number of subvolumes
-        the subvolume ids can go up to 2^64^ but the number of actual subvolumes
-        depends on the available metadata space, the space consumed by all subvolume
-        metadata includes bookkeeping of shared extents can be large (MiB, GiB)
-
-maximum number of hardlinks of a file in a directory
-        65536 when the *extref* feature is turned on during mkfs (default), roughly
-        100 otherwise
-
-minimum filesystem size
-        the minimal size of each device depends on the *mixed-bg* feature, without that
-        (the default) it's about 109MiB, with mixed-bg it's is 16MiB
-
+.. include:: ch-fs-limits.rst
 
 BOOTLOADER SUPPORT
 ------------------

Documentation/ch-fs-limits.rst

@@ -0,0 +1,33 @@
+maximum file name length
+        255
+
+maximum symlink target length
+        depends on the *nodesize* value, for 4KiB it's 3949 bytes, for larger nodesize
+        it's 4095 due to the system limit PATH_MAX
+
+        The symlink target may not be a valid path, ie. the path name components
+        can exceed the limits (NAME_MAX), there's no content validation at ``symlink(3)``
+        creation.
+
+maximum number of inodes
+        2^64^ but depends on the available metadata space as the inodes are created
+        dynamically
+
+inode numbers
+        minimum number: 256 (for subvolumes), regular files and directories: 257
+
+maximum file length
+        inherent limit of btrfs is 2^64^ (16 EiB) but the linux VFS limit is 2^63^ (8 EiB)
+
+maximum number of subvolumes
+        the subvolume ids can go up to 2^64^ but the number of actual subvolumes
+        depends on the available metadata space, the space consumed by all subvolume
+        metadata includes bookkeeping of shared extents can be large (MiB, GiB)
+
+maximum number of hardlinks of a file in a directory
+        65536 when the *extref* feature is turned on during mkfs (default), roughly
+        100 otherwise
+
+minimum filesystem size
+        the minimal size of each device depends on the *mixed-bg* feature, without that
+        (the default) it's about 109MiB, with mixed-bg it's is 16MiB