- 11 Aug, 2014 2 commits
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Al Viro authored
Since 3.14 we had copy_tree() get the shadowing wrong - if we had one vfsmount shadowing another (i.e. if A is a slave of B, C is mounted on A/foo, then D got mounted on B/foo creating D' on A/foo shadowed by C), copy_tree() of A would make a copy of D' shadow the the copy of C, not the other way around. It's easy to fix, fortunately - just make sure that mount follows the one that shadows it in mnt_child as well as in mnt_hash, and when copy_tree() decides to attach a new mount, check if the last child it has added to the same parent should be shadowing the new one. And if it should, just use the same logics commit_tree() has - put the new mount into the hash and children lists right after the one that should shadow it. Cc: stable@vger.kernel.org [3.14 and later] Signed-off-by:Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
If DIO results in short write and sync write fails, we want to bugger off whether the DIO part has written anything or not; the logics on the return will take care of the right return value. Cc: stable@vger.kernel.org [3.16] Reported-by:
Anton Altaparmakov <aia21@cam.ac.uk> Signed-off-by:
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- 07 Aug, 2014 38 commits
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Al Viro authored
... instead of maximal size. Signed-off-by: -
Fengguang Wu authored
Signed-off-by:
Fengguang Wu <fengguang.wu@intel.com> Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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J. Bruce Fields authored
I believe this can only happen in the case of a corrupted filesystem. So -EIO looks like the appropriate error. Signed-off-by:
J. Bruce Fields <bfields@redhat.com> Signed-off-by:
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J. Bruce Fields authored
Minor documentation updates: - refer to d_obtain_alias rather than d_alloc_anon - explain when to use d_splice_alias and when d_materialise_unique. - cut some details of d_splice_alias/d_materialise_unique implementation. Signed-off-by:
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J. Bruce Fields authored
If we get to this point and discover the dentry is not a root dentry, or not DCACHE_DISCONNECTED--great, we always prefer that anyway. Signed-off-by:
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J. Bruce Fields authored
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J. Bruce Fields authored
There are a few d_obtain_alias callers that are using it to get the root of a filesystem which may already have an alias somewhere else. This is not the same as the filehandle-lookup case, and none of them actually need DCACHE_DISCONNECTED set. It isn't really a serious problem, but it would really be clearer if we reserved DCACHE_DISCONNECTED for those cases where it's actually needed. In the btrfs case this was causing a spurious printk from nfsd/nfsfh.c:fh_verify when it found an unexpected DCACHE_DISCONNECTED dentry. Josef worked around this by unsetting DCACHE_DISCONNECTED manually in 3a0dfa6a "Btrfs: unset DCACHE_DISCONNECTED when mounting default subvol", and this replaces that workaround. Cc: Josef Bacik <jbacik@fb.com> Signed-off-by:
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J. Bruce Fields authored
Any IS_ROOT() alias should be safe to use; there's nothing special about DCACHE_DISCONNECTED dentries. Note that this is in fact useful for filesystems such as btrfs which can legimately encounter a directory with a preexisting IS_ROOT alias on a lookup that crosses into a subvolume. (Those aliases are currently marked DCACHE_DISCONNECTED--but not really for any good reason, and we'll change that soon.) Signed-off-by:
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J. Bruce Fields authored
Currently if d_splice_alias finds a directory with an alias that is not IS_ROOT or not DCACHE_DISCONNECTED, it creates a duplicate directory. Duplicate directory dentries are unacceptable; it is better just to error out. (In the case of a local filesystem the most likely case is filesystem corruption: for example, perhaps two directories point to the same child directory, and the other parent has already been found and cached.) Note that distributed filesystems may encounter this case in normal operation if a remote host moves a directory to a location different from the one we last cached in the dcache. For that reason, such filesystems should instead use d_materialise_unique, which tries to move the old directory alias to the right place instead of erroring out. Signed-off-by:
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J. Bruce Fields authored
d_splice_alias will d_move an IS_ROOT() directory dentry into place if one exists. This should be safe as long as the dentry remains IS_ROOT, but I can't see what guarantees that: once we drop the i_lock all we hold here is the i_mutex on an unrelated parent directory. Instead copy the logic of d_materialise_unique. Reviewed-by:
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J. Bruce Fields authored
Just a trivial move to locate it near (similar) d_materialise_unique code and save some forward references in a following patch. Reviewed-by:
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J. Bruce Fields authored
Looks like the directory loop check is actually done in renameat? Whatever, leave this out rather than trying to keep it up to date with the code. Signed-off-by:
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NeilBrown authored
In REF-walk mode, ->d_manage can return -EISDIR to indicate that the dentry is not really a mount trap (or even a mount point) and that any mounts or any DCACHE_NEED_AUTOMOUNT flag should be ignored. RCU-walk mode doesn't currently support this, so if there is a dentry with DCACHE_NEED_AUTOMOUNT set but which shouldn't be a mount-trap, lookup_fast() will always drop in REF-walk mode. With this patch, an -EISDIR from ->d_manage will always cause mounts and automounts to be ignored, both in REF-walk and RCU-walk. Bug-fixed-by:
Dan Carpenter <dan.carpenter@oracle.com> Cc: Ian Kent <raven@themaw.net> Signed-off-by:
NeilBrown <neilb@suse.de> Signed-off-by:
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Miklos Szeredi authored
This flag gives CIFS the ability to support its native rename semantics. Implementation is simple: just bail out before trying to hack around the noreplace semantics. Signed-off-by:
Miklos Szeredi <mszeredi@suse.cz> Cc: Steve French <smfrench@gmail.com> Signed-off-by:
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Miklos Szeredi authored
Support RENAME_NOREPLACE and RENAME_EXCHANGE flags on hostfs if the underlying filesystem supports it. Since renameat2(2) is not yet in any libc, use syscall(2) to invoke the renameat2 syscall. Signed-off-by:
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Miklos Szeredi authored
This is really simple in tmpfs since the VFS already takes care of shuffling the dentries. Just adjust nlink on parent directories and touch c & mtimes. Signed-off-by:
Hugh Dickins <hughd@google.com> Signed-off-by:
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Miklos Szeredi authored
Implement ->rename2 instead of ->rename. Signed-off-by:
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Miklos Szeredi authored
RENAME_NOREPLACE is trivial to implement for most filesystems: switch over to ->rename2() and check for the supported flags. The rest is done by the VFS. Signed-off-by:
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Miklos Szeredi authored
so we return -EIO instead of -EINVAL. Signed-off-by:
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Miklos Szeredi authored
Christoph Hellwig suggests: 1) make vfs_rename call ->rename2 if it exists instead of ->rename 2) switch all filesystems that you're adding NOREPLACE support for to use ->rename2 3) see how many ->rename instances we'll have left after a few iterations of 2. Signed-off-by:
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Ionut Alexa authored
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Ionut Alexa <ionut.m.alexa@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
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Al Viro authored
Rather than playing silly buggers with vfsmount refcounts, just have acct_on() ask fs/namespace.c for internal clone of file->f_path.mnt and replace it with said clone. Then attach the pin to original vfsmount. Voila - the clone will be alive until the file gets closed, making sure that underlying superblock remains active, etc., and we can drop the original vfsmount, so that it's not kept busy. If the file lives until the final mntput of the original vfsmount, we'll notice that there's an fs_pin (one in bsd_acct_struct that holds that file) and mnt_pin_kill() will take it out. Since ->kill() is synchronous, we won't proceed past that point until these files are closed (and private clones of our vfsmount are gone), so we get the same ordering warranties we used to get. mnt_pin()/mnt_unpin()/->mnt_pinned is gone now, and good riddance - it never became usable outside of kernel/acct.c (and racy wrt umount even there). Signed-off-by: -
Al Viro authored
These externs belong in fs/internal.h. Rename (they are not acct-specific anymore) and move them over there. Signed-off-by: -
Al Viro authored
Add a new field to fs_pin - kill(pin). That's what umount and r/o remount will be calling for all pins attached to vfsmount and superblock resp. Called after bumping the refcount, so it won't go away under us. Dropping the refcount is responsibility of the instance. All generic stuff moved to fs/fs_pin.c; the next step will rip all the knowledge of kernel/acct.c from fs/super.c and fs/namespace.c. After that - death to mnt_pin(); it was intended to be usable as generic mechanism for code that wants to attach objects to vfsmount, so that they would not make the sucker busy and would get killed on umount. Never got it right; it remained acct.c-specific all along. Now it's very close to being killable. Signed-off-by: -
Al Viro authored
pull generic parts into struct fs_pin. Eventually we want those to replace mnt_pin()/mnt_unpin() mess; that stuff will move to fs/*. Signed-off-by: -
Al Viro authored
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Al Viro authored
Do actual closing of file via schedule_work(). And use __fput_sync() there. Signed-off-by: -
Al Viro authored
just repeat the frozen check after regaining it, and check that sb is still alive. If several threads hit acct_auto_close() at the same time, acct_auto_close() will survive that just fine. And we really don't want to play with writes and closing the file with ->s_umount held exclusive - it's a deadlock country. Signed-off-by: -
Al Viro authored
* make acct->count atomic and acct freeing - rcu-delayed. * instead of grabbing acct_lock around the places where we take a reference, do that under rcu_read_lock() with atomic_long_inc_not_zero(). * have the new acct locked before making ns->bacct point to it Signed-off-by: -
Al Viro authored
Put these suckers on per-vfsmount and per-superblock lists instead. Note: right now it's still acct_lock for everything, but that's going to change. Signed-off-by: -
Al Viro authored
a) file can't be NULL b) file can't be changed under us c) all writes are serialized by acct->lock; no need to mess with spinlock there. Signed-off-by: -
Al Viro authored
Do not reuse bsd_acct_struct after closing the damn thing. Structure lifetime is controlled by refcount now. We also have a mutex in there, held over closing and writing (the file is O_APPEND, so we are not losing any concurrency). As the result, we do not need to bother with get_file()/fput() on log write anymore. Moreover, do_acct_process() only needs acct itself; file and pidns are picked from it. Killed instances are distinguished by having NULL ->ns. Refcount is protected by acct_lock; anybody taking the mutex needs to grab a reference first. The things will get a lot simpler in the next commits - this is just the minimal chunk switching to the new lifetime rules. Signed-off-by: -
Al Viro authored
brute-force - on a global mutex that isn't nested into anything. Signed-off-by: -
Al Viro authored
We need to check free space on the first write to freshly opened log. Signed-off-by: -
Al Viro authored
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Al Viro authored
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Al Viro authored
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Al Viro authored
There was an amusing bogosity in ac_rw calculation - it tried to do encode_comp_t(encode_comp_t(0) / 1024). Seeing that comp_t is a 3-bit exponent + 13-bit mantissa... it's a good thing that 0 is represented by all-bits-clear. The history of that one is interesting - it was introduced in 2.1.68pre1, when acct.c had been reworked and moved to separate file. Two months later (2.1.86) somebody has noticed that the sucker won't compile - there was no task_struct::io_usage. At which point the ac_io calculation had changed from encode_comp_t(current->io_usage) to encode_comp_t(0) and the bug in the next line (absolutely real back then, had it ever managed to compile) become a harmless bogosity. Looks like nobody has ever noticed until now. Anyway, let's bury that idiocy now that it got noticed. 17 years is long enough... Signed-off-by:
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