| Changes from version 0.5a to version 0.5b |
| ========================================= |
| - Now that we have sysctl(), the immutable flag cannot be changed when |
| the system is running at security level > 0. |
| - Some cleanups in the code. |
| - More consistency checks on directories. |
| - The ext2.diff patch from Tom May <ftom@netcom.com> has been |
| integrated. This patch replaces expensive "/" and "%" with |
| cheap ">>" and "&" where possible. |
| |
| Changes from version 0.5 to version 0.5a |
| ======================================== |
| - Zero the partial block following the end of the file when a file |
| is truncated. |
| - Dates updated in the copyright. |
| - More checks when the filesystem is mounted: the count of blocks, |
| fragments, and inodes per group is checked against the block size. |
| - The buffers used by the error routines are now static variables, to |
| avoid using space on the kernel stack, as requested by Linus. |
| - Some cleanups in the error messages (some versions of syslog contain |
| a bug which truncates an error message if it contains '\n'). |
| - Check that no data can be written to a file past the 2GB limit. |
| - The famous readdir() bug has been fixed by Stephen Tweedie. |
| - Added a revision level in the superblock. |
| - Full support for O_SYNC flag of the open system call. |
| - New mount options: `resuid=#uid' and `resgid=#gid'. `resuid' causes |
| ext2fs to consider user #uid like root for the reserved blocks. |
| `resgid' acts the same way with group #gid. New fields in the |
| superblock contain default values for resuid and resgid and can |
| be modified by tune2fs. |
| Idea comes from Rene Cougnenc <cougnenc@renux.frmug.fr.net>. |
| - New mount options: `bsddf' and `minixdf'. `bsddf' causes ext2fs |
| to remove the blocks used for FS structures from the total block |
| count in statfs. With `minixdf', ext2fs mimics Minix behavior |
| in statfs (i.e. it returns the total number of blocks on the |
| partition). This is intended to make bde happy :-) |
| - New file attributes: |
| - Immutable files cannot be modified. Data cannot be written to |
| these files. They cannot be removed, renamed and new links cannot |
| be created. Even root cannot modify the files. He has to remove |
| the immutable attribute first. |
| - Append-only files: can only be written in append-mode when writing. |
| They cannot be removed, renamed and new links cannot be created. |
| Note: files may only be added to an append-only directory. |
| - No-dump files: the attribute is not used by the kernel. My port |
| of dump uses it to avoid backing up files which are not important. |
| - New check in ext2_check_dir_entry: the inode number is checked. |
| - Support for big file systems: the copy of the FS descriptor is now |
| dynamically allocated (previous versions used a fixed size array). |
| This allows to mount 2GB+ FS. |
| - Reorganization of the ext2_inode structure to allow other operating |
| systems to create specific fields if they use ext2fs as their native |
| file system. Currently, ext2fs is only implemented in Linux but |
| will soon be part of Gnu Hurd and of Masix. |
| |
| Changes from version 0.4b to version 0.5 |
| ======================================== |
| - New superblock fields: s_lastcheck and s_checkinterval added |
| by Uwe Ohse <uwe@tirka.gun.de> to implement timedependent checks |
| of the file system |
| - Real random numbers for secure rm added by Pierre del Perugia |
| <delperug@gla.ecoledoc.ibp.fr> |
| - The mount warnings related to the state of a fs are not printed |
| if the fs is mounted read-only, idea by Nick Holloway |
| <alfie@dcs.warwick.ac.uk> |
| |
| Changes from version 0.4a to version 0.4b |
| ========================================= |
| - Copyrights changed to include the name of my laboratory. |
| - Clean up of balloc.c and ialloc.c. |
| - More consistency checks. |
| - Block preallocation added by Stephen Tweedie. |
| - Direct reads of directories disallowed. |
| - Readahead implemented in readdir by Stephen Tweedie. |
| - Bugs in block and inodes allocation fixed. |
| - Readahead implemented in ext2_find_entry by Chip Salzenberg. |
| - New mount options: |
| `check=none|normal|strict' |
| `debug' |
| `errors=continue|remount-ro|panic' |
| `grpid', `bsdgroups' |
| `nocheck' |
| `nogrpid', `sysvgroups' |
| - truncate() now tries to deallocate contiguous blocks in a single call |
| to ext2_free_blocks(). |
| - lots of cosmetic changes. |
| |
| Changes from version 0.4 to version 0.4a |
| ======================================== |
| - the `sync' option support is now complete. Version 0.4 was not |
| supporting it when truncating a file. I have tested the synchronous |
| writes and they work but they make the system very slow :-( I have |
| to work again on this to make it faster. |
| - when detecting an error on a mounted filesystem, version 0.4 used |
| to try to write a flag in the super block even if the filesystem had |
| been mounted read-only. This is fixed. |
| - the `sb=#' option now causes the kernel code to use the filesystem |
| descriptors located at block #+1. Version 0.4 used the superblock |
| backup located at block # but used the main copy of the descriptors. |
| - a new file attribute `S' is supported. This attribute causes |
| synchronous writes but is applied to a file not to the entire file |
| system (thanks to Michael Kraehe <kraehe@bakunin.north.de> for |
| suggesting it). |
| - the directory cache is inhibited by default. The cache management |
| code seems to be buggy and I have to look at it carefully before |
| using it again. |
| - deleting a file with the `s' attribute (secure deletion) causes its |
| blocks to be overwritten with random values not with zeros (thanks to |
| Michael A. Griffith <grif@cs.ucr.edu> for suggesting it). |
| - lots of cosmetic changes have been made. |
| |
| Changes from version 0.3 to version 0.4 |
| ======================================= |
| - Three new mount options are supported: `check', `sync' and `sb=#'. |
| `check' tells the kernel code to make more consistency checks |
| when the file system is mounted. Currently, the kernel code checks |
| that the blocks and inodes bitmaps are consistent with the free |
| blocks and inodes counts. More checks will be added in future |
| releases. |
| `sync' tells the kernel code to use synchronous writes when updating |
| an inode, a bitmap, a directory entry or an indirect block. This |
| can make the file system much slower but can be a big win for files |
| recovery in case of a crash (and we can now say to the BSD folks |
| that Linux also supports synchronous updates :-). |
| `sb=#' tells the kernel code to use an alternate super block instead |
| of its master copy. `#' is the number of the block (counted in |
| 1024 bytes blocks) which contains the alternate super block. |
| An ext2 file system typically contains backups of the super block |
| at blocks 8193, 16385, and so on. |
| - I have change the meaning of the valid flag used by e2fsck. it |
| now contains the state of the file system. If the kernel code |
| detects an inconsistency while the file system is mounted, it flags |
| it as erroneous and e2fsck will detect that on next run. |
| - The super block now contains a mount counter. This counter is |
| incremented each time the file system is mounted read/write. When |
| this counter becomes bigger than a maximal mount counts (also stored |
| in the super block), e2fsck checks the file system, even if it had |
| been unmounted cleanly, and resets this counter to 0. |
| - File attributes are now supported. One can associate a set of |
| attributes to a file. Three attributes are defined: |
| `c': the file is marked for automatic compression, |
| `s': the file is marked for secure deletion: when the file is |
| deleted, its blocks are zeroed and written back to the disk, |
| `u': the file is marked for undeletion: when the file is deleted, |
| its contents are saved to allow a future undeletion. |
| Currently, only the `s' attribute is implemented in the kernel |
| code. Support for the other attributes will be added in a future |
| release. |
| - a few bugs related to times updates have been fixed by Bruce |
| Evans and me. |
| - a bug related to the links count of deleted inodes has been fixed. |
| Previous versions used to keep the links count set to 1 when a file |
| was deleted. The new version now sets links_count to 0 when deleting |
| the last link. |
| - a race condition when deallocating an inode has been fixed by |
| Stephen Tweedie. |
| |
