Conditional mntput() moved into __do_follow_link(). There it collapses with
unconditional mntget() on the same sucker, closing another too-early-mntput()
race.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Getting rid of sloppy logics:
a) in do_follow_link() we have the wrong vfsmount dropped if our symlink
had been mounted on something. Currently it worls only because we never
get such situation (modulo filesystem playing dirty tricks on us). And
it obfuscates already convoluted logics...
b) same goes for open_namei().
c) in __link_path_walk() we have another "it should never happen" sloppiness -
out_dput: there does double-free on underlying vfsmount and leaks the covering
one if we hit it just after crossing a mountpoint. Again, wrong vfsmount
getting dropped.
d) another too-early-mntput() race - in do_follow_mount() we need to postpone
conditional mntput(path->mnt) until after dput(path->dentry). Again, this one
happens only in it-currently-never-happens-unless-some-fs-plays-dirty
scenario...
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
shifted conditional mntput() into do_follow_link() - all callers were doing
the same thing.
Obviously equivalent transformation.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In open_namei() exit_dput: we have mntput() done in the wrong order -
if nd->mnt != path.mnt we end up doing
mntput(nd->mnt);
nd->mnt = path.mnt;
dput(nd->dentry);
mntput(nd->mnt);
which drops nd->dentry too late. Fixed by having path.mnt go first.
That allows to switch O_NOFOLLOW under if (__follow_mount(...)) back
to exit_dput, while we are at it.
Fix for early-mntput() race + equivalent transformation.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In open_namei() we take mntput(nd->mnt);nd->mnt=path.mnt; out of the if
(__follow_mount(...)), making it conditional on nd->mnt != path.mnt instead.
Then we shift the result downstream.
Equivalent transformations.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In open_namei(), __follow_down() loop turned into __follow_mount().
Instead of
if we are on a mountpoint dentry
if O_NOFOLLOW checks fail
drop path.dentry
drop nd
return
do equivalent of follow_mount(&path.mnt, &path.dentry)
nd->mnt = path.mnt
we do
if __follow_mount(path) had, indeed, traversed mountpoint
/* now both nd->mnt and path.mnt are pinned down */
if O_NOFOLLOW checks fail
drop path.dentry
drop path.mnt
drop nd
return
mntput(nd->mnt)
nd->mnt = path.mnt
Now __follow_down() can be folded into follow_down() - no other callers left.
We need to reorder dput()/mntput() there - same problem as in follow_mount().
Equivalent transformation + fix for a bug in O_NOFOLLOW handling - we used to
get -ELOOP if we had the same fs mounted on /foo and /bar, had something bound
on /bar/baz and tried to open /foo/baz with O_NOFOLLOW. And fix of
too-early-mntput() race in follow_down()
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
New helper: __follow_mount(struct path *path). Same as follow_mount(), except
that we do *not* do mntput() after the first lookup_mnt().
IOW, original path->mnt stays pinned down. We also take care to do dput()
before mntput() in the loop body (follow_mount() also needs that reordering,
but that will be done later in the series).
The following are equivalent, assuming that path.mnt == x:
(1)
follow_mount(&path.mnt, &path.dentry)
(2)
__follow_mount(&path);
if (path->mnt != x)
mntput(x);
(3)
if (__follow_mount(&path))
mntput(x);
Callers of follow_mount() in __link_path_walk() converted to (2).
Equivalent transformation + fix for too-late-mntput() race in __follow_mount()
loop.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In open_namei() we never use path.mnt or path.dentry after exit: or ok:.
Assignment of path.dentry in case of LAST_BIND is dead code and only
obfuscates already convoluted function; assignment of path.mnt after
__do_follow_link() can be moved down to the place where we set path.dentry.
Obviously equivalent transformations, just to clean the air a bit in that
region.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The first argument of __do_follow_link() switched to struct path *
(__do_follow_link(path->dentry, ...) -> __do_follow_link(path, ...)).
All callers have the same calls of mntget() right before and dput()/mntput()
right after __do_follow_link(); these calls have been moved inside.
Obviously equivalent transformations.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
mntget(path->mnt) in do_follow_link() moved down to right before the
__do_follow_link() call and rigth after loop: resp.
dput()+mntput() on non-ELOOP branch moved up to right after __do_follow_link()
call.
resulting
loop:
mntget(path->mnt);
path_release(nd);
dput(path->mnt);
mntput(path->mnt);
replaced with equivalent
dput(path->mnt);
path_release(nd);
Equivalent transformations - the reason why we have that mntget() is that
__do_follow_link() can drop a reference to nd->mnt and that's what holds
path->mnt. So that call can happen at any point prior to __do_follow_link()
touching nd->mnt. The rest is obvious.
NOTE: current tree relies on symlinks *never* being mounted on anything. It's
not hard to get rid of that assumption (actually, that will come for free
later in the series). For now we are just not making the situation worse than
it is.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fix for too early mntput() in open_namei() - we pin path.mnt down for the
duration of __do_follow_link(). Otherwise we could get the fs where our
symlink lived unmounted while we were in __do_follow_link(). That would end
up with dentry of symlink staying pinned down through the fs shutdown.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
path.mnt in open_namei() set to mirror nd->mnt.
nd->mnt is set in 3 places in that function - path_lookup() in the beginning,
__follow_down() loop after do_last: and __do_follow_link() call after
do_link:.
We set path.mnt to nd->mnt after path_lookup() and __do_follow_link(). In
__follow_down() loop we use &path.mnt instead of &nd->mnt and set nd->mnt to
path.mnt immediately after that loop.
Obviously equivalent transformation.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Replaced struct dentry *dentry in namei with struct path path. All uses of
dentry replaced with path.dentry there.
Obviously equivalent transformation.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
All callers of do_follow_link() do mntget() right before it and
dput()+mntput() right after. These calls are moved inside do_follow_link()
now.
Obviously equivalent transformation.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
OK, here comes a patch series that hopefully should close all
too-early-mntput() races in fs/namei.c. Entire area is convoluted as hell, so
I'm splitting that series into _very_ small chunks.
Patches alread in the tree close only (very wide) races in following symlinks
(see "busy inodes after umount" thread some time ago). Unfortunately, quite a
few narrower races of the same nature were not closed. Hopefully this should
take care of all of them.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When fsync() runs wait_on_page_writeback_range() it only inspects pages which
are actually under I/O (PAGECACHE_TAG_WRITEBACK). If a page completed I/O
prior to wait_on_page_writeback_range() looking at it, it is supposed to have
recorded its I/O error state in the address_space.
But mpage_mpage_end_io_write() forgot to set the address_space error flag in
this case.
Signed-off-by: Qu Fuping <fs@ercist.iscas.ac.cn>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fs/jfs/jfs_logmgr.c: In function `jfs_flush_journal':
fs/jfs/jfs_logmgr.c:1632: warning: unused variable `mp'
Some debug code in jfs_flush_journal does nothing when CONFIG_JFS_DEBUG
is not defined. Place the whole code segment within an ifdef to avoid
unnecessary code to be compiled and the warning to be issued.
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Fix a bug in list scanning that can cause us to skip the last buffer on the
checkpoint list (and hence fail to do any progress under some rather
unfavorable conditions).
The problem is we first do jh=next_jh and then test
} while (jh!=last_jh);
Hence we skip the last buffer on the list (if it was not the only buffer on
the list). As we already do jh=next_jh; in the beginning of the loop we
are safe to just remove the assignment in the end. It can happen that 'jh'
will be freed at the point we test jh != last_jh but that does not matter
as we never *dereference* the pointer.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix possible false assertion failure in log_do_checkpoint(). We might fail
to detect that we actually made a progress when cleaning up the checkpoint
lists if we don't retry after writing something to disk. The patch was
confirmed to fix observed assertion failures for several users.
When we flushed some buffers we need to retry scanning the list.
Otherwise we can fail to detect our progress.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
add_missing_indices() must set tlck->type to tlckBTROOT when modifying
a root btree root to avoid a trap in txRelease()
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
This cleans up the /proc/device-tree representation of the Open Firmware
device-tree on ppc and ppc64. It does the following things:
- Workaround an issue in some Apple device-trees where a property may
exist with the same name as a child node of the parent. We now
simply "drop" the property instead of creating duplicate entries in
/proc with random result...
- Do not try to chop off the "@0" at the end of a node name whose unit
address is 0. This is not useful, inconsistent, and the code was
buggy and didn't always work anyway.
- Do not create symlinks for the short name and unit address parts of a
node. These were never really used, bloated the memory footprint of
the device-tree with useless struct proc_dir_entry and their matching
dentry and inode cache bloat.
This results in smaller code, smaller memory footprint, and a more
accurate view of the tree presented to userland.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
in fs/udf/udftime.c the global array '__mon_yday' is not static, and it
conflicts with the glibc one when the kernel is compiled as user mode.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove old useless header that was used in Ye Olde Times during 2.4->2.5
porting to abstract differences. It's definitions are no more used anyway, so
let's finally kill it.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Do not call wait_for_completion, when the gc task is not there.
Prevent an oops when the gc thread was not started.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
First kill GC thread, then start clearing the internal structures
Signed-off-by: Artem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fix the bug that caouses problems when compiling for NOR.
We read a newly erased block so we don't need to check ECC.
Define jffs2_is_writebuffered as zero if there is no wbuf.
Signed-off-by: Artem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Make sure the erase_pending_wbuf_list's blocks are taken into account
when picking the block to GC.
Signed-off-by: Artem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Use the corresponding function to mark Superblock dirty instead
of doing it directly.
Signed-off-by: Artem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fix fairly sad NOR-specific bug - during FS building ic->scan_dents
isn't zero, but jffs2_mark_node_obsolete() migt be called it tries to
finde the ic corresponding to ref - this requires ic->scan_dents = 0.
Signed-off-by: Artem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Don't remove inocache for inodes which are in read_inode() or
clear_inode() until they're done.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Look the ref->next_phys field instead of ->next_in_ino to determine
if the block has more then one node.
Signed-off-by: Artem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch replaces the current CONFIG_JFFS2_FS_NAND, CONFIG_JFFS2_FS_NOR_ECC
and CONFIG_JFFS2_FS_DATAFLASH with a single configuration option -
CONFIG_JFFS2_FS_WRITEBUFFER.
The only functional change of this patch is that the slower div/mod
calculations for SECTOR_ADDR(), PAGE_DIV() and PAGE_MOD() are now always
used when CONFIG_JFFS2_FS_WRITEBUFFER is enabled.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
For Dataflash, can_mark_obsolete = false and the NAND write buffering
code (wbuf.c) is used.
Since the DataFlash chip will automatically erase pages when writing,
the cleanmarkers are not needed - so cleanmarker_oob = false and
cleanmarker_size = 0
DataFlash page-sizes are not a power of two (they're multiples of 528
bytes). The SECTOR_ADDR macro (added in the previous core patch) is
replaced with a (slower) div/mod version if CONFIG_JFFS2_FS_DATAFLASH is
selected.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
DataFlash page-sizes are not a power of two (they're multiples of 528
bytes). There are a few places in JFFS2 code where sector_size is used
as a bitmask. A new macro (SECTOR_ADDR) was defined to calculate these
sector addresses. For non-DataFlash devices, the original (faster)
bitmask operation is still used.
In scan.c, the EMPTY_SCAN_SIZE was a constant of 1024.
Since this could be larger than the sector size of the DataFlash, this
is now basically set to MIN(sector_size, 1024).
Addition of a jffs2_is_writebuffered() macro.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Al Viro