#include #include #include #include #include "omfs.h" unsigned long omfs_count_free(struct super_block *sb) { unsigned int i; unsigned long sum = 0; struct omfs_sb_info *sbi = OMFS_SB(sb); int nbits = sb->s_blocksize * 8; for (i = 0; i < sbi->s_imap_size; i++) sum += nbits - bitmap_weight(sbi->s_imap[i], nbits); return sum; } /* * Counts the run of zero bits starting at bit up to max. * It handles the case where a run might spill over a buffer. * Called with bitmap lock. */ static int count_run(unsigned long **addr, int nbits, int addrlen, int bit, int max) { int count = 0; int x; for (; addrlen > 0; addrlen--, addr++) { x = find_next_bit(*addr, nbits, bit); count += x - bit; if (x < nbits || count > max) return min(count, max); bit = 0; } return min(count, max); } /* * Sets or clears the run of count bits starting with bit. * Called with bitmap lock. */ static int set_run(struct super_block *sb, int map, int nbits, int bit, int count, int set) { int i; int err; struct buffer_head *bh; struct omfs_sb_info *sbi = OMFS_SB(sb); err = -ENOMEM; bh = sb_bread(sb, clus_to_blk(sbi, sbi->s_bitmap_ino) + map); if (!bh) goto out; for (i = 0; i < count; i++, bit++) { if (bit >= nbits) { bit = 0; map++; mark_buffer_dirty(bh); brelse(bh); bh = sb_bread(sb, clus_to_blk(sbi, sbi->s_bitmap_ino) + map); if (!bh) goto out; } if (set) { set_bit(bit, sbi->s_imap[map]); set_bit(bit, (unsigned long *)bh->b_data); } else { clear_bit(bit, sbi->s_imap[map]); clear_bit(bit, (unsigned long *)bh->b_data); } } mark_buffer_dirty(bh); brelse(bh); err = 0; out: return err; } /* * Tries to allocate exactly one block. Returns true if successful. */ int omfs_allocate_block(struct super_block *sb, u64 block) { struct buffer_head *bh; struct omfs_sb_info *sbi = OMFS_SB(sb); int bits_per_entry = 8 * sb->s_blocksize; unsigned int map, bit; int ret = 0; u64 tmp; tmp = block; bit = do_div(tmp, bits_per_entry); map = tmp; mutex_lock(&sbi->s_bitmap_lock); if (map >= sbi->s_imap_size || test_and_set_bit(bit, sbi->s_imap[map])) goto out; if (sbi->s_bitmap_ino > 0) { bh = sb_bread(sb, clus_to_blk(sbi, sbi->s_bitmap_ino) + map); if (!bh) goto out; set_bit(bit, (unsigned long *)bh->b_data); mark_buffer_dirty(bh); brelse(bh); } ret = 1; out: mutex_unlock(&sbi->s_bitmap_lock); return ret; } /* * Tries to allocate a set of blocks. The request size depends on the * type: for inodes, we must allocate sbi->s_mirrors blocks, and for file * blocks, we try to allocate sbi->s_clustersize, but can always get away * with just one block. */ int omfs_allocate_range(struct super_block *sb, int min_request, int max_request, u64 *return_block, int *return_size) { struct omfs_sb_info *sbi = OMFS_SB(sb); int bits_per_entry = 8 * sb->s_blocksize; int ret = 0; int i, run, bit; mutex_lock(&sbi->s_bitmap_lock); for (i = 0; i < sbi->s_imap_size; i++) { bit = 0; while (bit < bits_per_entry) { bit = find_next_zero_bit(sbi->s_imap[i], bits_per_entry, bit); if (bit == bits_per_entry) break; run = count_run(&sbi->s_imap[i], bits_per_entry, sbi->s_imap_size-i, bit, max_request); if (run >= min_request) goto found; bit += run; } } ret = -ENOSPC; goto out; found: *return_block = (u64) i * bits_per_entry + bit; *return_size = run; ret = set_run(sb, i, bits_per_entry, bit, run, 1); out: mutex_unlock(&sbi->s_bitmap_lock); return ret; } /* * Clears count bits starting at a given block. */ int omfs_clear_range(struct super_block *sb, u64 block, int count) { struct omfs_sb_info *sbi = OMFS_SB(sb); int bits_per_entry = 8 * sb->s_blocksize; u64 tmp; unsigned int map, bit; int ret; tmp = block; bit = do_div(tmp, bits_per_entry); map = tmp; if (map >= sbi->s_imap_size) return 0; mutex_lock(&sbi->s_bitmap_lock); ret = set_run(sb, map, bits_per_entry, bit, count, 0); mutex_unlock(&sbi->s_bitmap_lock); return ret; } elected='selected'>3space:mode:
authorOndrej Kozina <okozina@redhat.com>2017-01-31 15:47:11 +0100
committerMike Snitzer <snitzer@redhat.com>2017-02-03 10:26:14 -0500
commitf5b0cba8f23915e92932f11eb063e37d70556a89 (patch)
tree19f7ccac636459333cca52027914d19084b1392b /drivers/usb/host/uhci-debug.c
parent4087a1fffe38106e10646606a27f10d40451862d (diff)
dm crypt: replace RCU read-side section with rwsem
The lockdep splat below hints at a bug in RCU usage in dm-crypt that was introduced with commit c538f6ec9f56 ("dm crypt: add ability to use keys from the kernel key retention service"). The kernel keyring function user_key_payload() is in fact a wrapper for rcu_dereference_protected() which must not be called with only rcu_read_lock() section mark. Unfortunately the kernel keyring subsystem doesn't currently provide an interface that allows the use of an RCU read-side section. So for now we must drop RCU in favour of rwsem until a proper function is made available in the kernel keyring subsystem. =============================== [ INFO: suspicious RCU usage. ] 4.10.0-rc5 #2 Not tainted ------------------------------- ./include/keys/user-type.h:53 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by cryptsetup/6464: #0: (&md->type_lock){+.+.+.}, at: [<ffffffffa02472a2>] dm_lock_md_type+0x12/0x20 [dm_mod] #1: (rcu_read_lock){......}, at: [<ffffffffa02822f8>] crypt_set_key+0x1d8/0x4b0 [dm_crypt] stack backtrace: CPU: 1 PID: 6464 Comm: cryptsetup Not tainted 4.10.0-rc5 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014 Call Trace: dump_stack+0x67/0x92 lockdep_rcu_suspicious+0xc5/0x100 crypt_set_key+0x351/0x4b0 [dm_crypt] ? crypt_set_key+0x1d8/0x4b0 [dm_crypt] crypt_ctr+0x341/0xa53 [dm_crypt] dm_table_add_target+0x147/0x330 [dm_mod] table_load+0x111/0x350 [dm_mod] ? retrieve_status+0x1c0/0x1c0 [dm_mod] ctl_ioctl+0x1f5/0x510 [dm_mod] dm_ctl_ioctl+0xe/0x20 [dm_mod] do_vfs_ioctl+0x8e/0x690 ? ____fput+0x9/0x10 ? task_work_run+0x7e/0xa0 ? trace_hardirqs_on_caller+0x122/0x1b0 SyS_ioctl+0x3c/0x70 entry_SYSCALL_64_fastpath+0x18/0xad RIP: 0033:0x7f392c9a4ec7 RSP: 002b:00007ffef6383378 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffef63830a0 RCX: 00007f392c9a4ec7 RDX: 000000000124fcc0 RSI: 00000000c138fd09 RDI: 0000000000000005 RBP: 00007ffef6383090 R08: 00000000ffffffff R09: 00000000012482b0 R10: 2a28205d34383336 R11: 0000000000000246 R12: 00007f392d803a08 R13: 00007ffef63831e0 R14: 0000000000000000 R15: 00007f392d803a0b Fixes: c538f6ec9f56 ("dm crypt: add ability to use keys from the kernel key retention service") Reported-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Ondrej Kozina <okozina@redhat.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/usb/host/uhci-debug.c')