Messages in this thread |  | | | Date | Thu, 24 Jun 1999 12:44:08 -0400 | | From | Brad Kemp <> | | Subject | Re: why is the size of a directory always 1024b ? |
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lost+found is a special case, the mklost+found pre-allocates empty directory entries so the fsck always has room to add lost directory entries
At 02:56 PM 6/24/99 +0530, MURALI N wrote: > >Please look at the listing below. > >"/" > >drwxr-xr-x 17 root root 1024 May 28 16:40 . >drwxr-xr-x 17 root root 1024 May 28 16:40 .. >drwxr-xr-x 2 root root 12288 May 4 21:35 lost+found >drwxr-xr-x 5 root root 1024 May 5 12:12 mnt >dr-xr-xr-x 33 root root 0 Jun 23 19:06 proc > >"lost+found" > >drwxr-xr-x 2 root root 12288 May 4 21:35 . >drwxr-xr-x 17 root root 1024 May 28 16:40 .. > >If the present scheme allocates 13 * 1024 bytes for just "." and "..", I >feel it is time to rethink the directory handling. > >> Albert, look at the ext2/ufs/ffs directory layout. You'll see the >reason. >> Blocks *are* filled. Completely. Fresh directory (after mkdir) >looks so: >> <inumber><size of 1st record><length of name (1)><name >(".")><slack> >> <inumber><size of 2nd record><length of name (2)><name >("..")><slack> >> <inumber (0, i.e. free><size of the 3rd record><slack> >>Each block is filled with records. Some records are marked free. Records >>may have a slack in the end. That's it. There is no meaningful sub-block >>boundary. > > ffs was designed that way. > > "the filesystem records free space in a directory by having >entries accumulate the free space in their fields. Space allocated to >directories should be accounted for completely by the total sizes of the >directory's entries.... If the first entry of a directory block is free, >then the pointer to that block in the directory's inode is set to zero to >indicate that the entry is unused." - 4.4 BSD - McKusick et.al. > > > > >- >To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >the body of a message to majordomo@vger.rutgers.edu >Please read the FAQ at http://www.tux.org/lkml/ > --- -- -- Brad Kemp Indus River Networks, Inc. BradKemp@indusriver.com 31 Nagog Park 978-266-8122 Acton, MA 01720 fax 978-266-8111
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