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path: root/fs/afs/dynroot.c
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2024-01-08afs: Fix the dynamic root's d_delete to always delete unused dentriesDavid Howells
[ Upstream commit 71f8b55bc30e82d6355e07811213d847981a32e2 ] Fix the afs dynamic root's d_delete function to always delete unused dentries rather than only deleting them if they're positive. With things as they stand upstream, negative dentries stemming from failed DNS lookups stick around preventing retries. Fixes: 66c7e1d319a5 ("afs: Split the dynroot stuff out and give it its own ops tables") Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Markus Suvanto <markus.suvanto@gmail.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26afs: Fix NULL deref in afs_dynroot_depopulate()David Howells
[ Upstream commit 5e0b17b026eb7c6de9baa9b0d45a51b05f05abe1 ] If an error occurs during the construction of an afs superblock, it's possible that an error occurs after a superblock is created, but before we've created the root dentry. If the superblock has a dynamic root (ie. what's normally mounted on /afs), the afs_kill_super() will call afs_dynroot_depopulate() to unpin any created dentries - but this will oops if the root hasn't been created yet. Fix this by skipping that bit of code if there is no root dentry. This leads to an oops looking like: general protection fault, ... KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f] ... RIP: 0010:afs_dynroot_depopulate+0x25f/0x529 fs/afs/dynroot.c:385 ... Call Trace: afs_kill_super+0x13b/0x180 fs/afs/super.c:535 deactivate_locked_super+0x94/0x160 fs/super.c:335 afs_get_tree+0x1124/0x1460 fs/afs/super.c:598 vfs_get_tree+0x89/0x2f0 fs/super.c:1547 do_new_mount fs/namespace.c:2875 [inline] path_mount+0x1387/0x2070 fs/namespace.c:3192 do_mount fs/namespace.c:3205 [inline] __do_sys_mount fs/namespace.c:3413 [inline] __se_sys_mount fs/namespace.c:3390 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3390 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 which is oopsing on this line: inode_lock(root->d_inode); presumably because sb->s_root was NULL. Fixes: 0da0b7fd73e4 ("afs: Display manually added cells in dynamic root mount") Reported-by: syzbot+c1eff8205244ae7e11a6@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-09afs: Fix creation calls in the dynamic root to fail with EOPNOTSUPPDavid Howells
[ Upstream commit 1da4bd9f9d187f53618890d7b66b9628bbec3c70 ] Fix the lookup method on the dynamic root directory such that creation calls, such as mkdir, open(O_CREAT), symlink, etc. fail with EOPNOTSUPP rather than failing with some odd error (such as EEXIST). lookup() itself tries to create automount directories when it is invoked. These are cached locally in RAM and not committed to storage. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> Tested-by: Jonathan Billings <jsbillings@jsbillings.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-10-12afs: Fix cell proc listDavid Howells
Access to the list of cells by /proc/net/afs/cells has a couple of problems: (1) It should be checking against SEQ_START_TOKEN for the keying the header line. (2) It's only holding the RCU read lock, so it can't just walk over the list without following the proper RCU methods. Fix these by using an hlist instead of an ordinary list and using the appropriate accessor functions to follow it with RCU. Since the code that adds a cell to the list must also necessarily change, sort the list on insertion whilst we're at it. Fixes: 989782dcdc91 ("afs: Overhaul cell database management") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-05afs_try_auto_mntpt(): return NULL instead of ERR_PTR(-ENOENT)Al Viro
simpler logics in callers that way Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-08-05afs: switch dynroot lookups to d_splice_alias()Al Viro
->lookup() methods can (and should) use d_splice_alias() instead of d_add(). Even if they are not going to be hit by open_by_handle(), code does get copied around... Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-06-15afs: Display manually added cells in dynamic root mountDavid Howells
Alter the dynroot mount so that cells created by manipulation of /proc/fs/afs/cells and /proc/fs/afs/rootcell and by specification of a root cell as a module parameter will cause directories for those cells to be created in the dynamic root superblock for the network namespace[*]. To this end: (1) Only one dynamic root superblock is now created per network namespace and this is shared between all attempts to mount it. This makes it easier to find the superblock to modify. (2) When a dynamic root superblock is created, the list of cells is walked and directories created for each cell already defined. (3) When a new cell is added, if a dynamic root superblock exists, a directory is created for it. (4) When a cell is destroyed, the directory is removed. (5) These directories are created by calling lookup_one_len() on the root dir which automatically creates them if they don't exist. [*] Inasmuch as network namespaces are currently supported here. Signed-off-by: David Howells <dhowells@redhat.com>
2018-06-15afs: Enable IPv6 DNS lookupsDavid Howells
Remove the restriction on DNS lookup upcalls that prevents ipv6 addresses from being looked up. Signed-off-by: David Howells <dhowells@redhat.com>
2018-04-09afs: Split the dynroot stuff out and give it its own ops tablesDavid Howells
Split the AFS dynamic root stuff out of the main directory handling file and into its own file as they share little in common. The dynamic root code also gets its own dentry and inode ops tables. Signed-off-by: David Howells <dhowells@redhat.com>