/* * linux/fs/sysv/ialloc.c * * minix/bitmap.c * Copyright (C) 1991, 1992 Linus Torvalds * * ext/freelists.c * Copyright (C) 1992 Remy Card (card@masi.ibp.fr) * * xenix/alloc.c * Copyright (C) 1992 Doug Evans * * coh/alloc.c * Copyright (C) 1993 Pascal Haible, Bruno Haible * * sysv/ialloc.c * Copyright (C) 1993 Bruno Haible * * This file contains code for allocating/freeing inodes. */ #include #include #include #include #include #include #include #include "sysv.h" /* We don't trust the value of sb->sv_sbd2->s_tinode = *sb->sv_sb_total_free_inodes but we nevertheless keep it up to date. */ /* An inode on disk is considered free if both i_mode == 0 and i_nlink == 0. */ /* return &sb->sv_sb_fic_inodes[i] = &sbd->s_inode[i]; */ static inline sysv_ino_t * sv_sb_fic_inode(struct super_block * sb, unsigned int i) { struct sysv_sb_info *sbi = SYSV_SB(sb); if (sbi->s_bh1 == sbi->s_bh2) return &sbi->s_sb_fic_inodes[i]; else { /* 512 byte Xenix FS */ unsigned int offset = offsetof(struct xenix_super_block, s_inode[i]); if (offset < 512) return (sysv_ino_t*)(sbi->s_sbd1 + offset); else return (sysv_ino_t*)(sbi->s_sbd2 + offset); } } struct sysv_inode * sysv_raw_inode(struct super_block *sb, unsigned ino, struct buffer_head **bh) { struct sysv_sb_info *sbi = SYSV_SB(sb); struct sysv_inode *res; int block = sbi->s_firstinodezone + sbi->s_block_base; block += (ino-1) >> sbi->s_inodes_per_block_bits; *bh = sb_bread(sb, block); if (!*bh) return NULL; res = (struct sysv_inode *)(*bh)->b_data; return res + ((ino-1) & sbi->s_inodes_per_block_1); } static int refill_free_cache(struct super_block *sb) { struct sysv_sb_info *sbi = SYSV_SB(sb); struct buffer_head * bh; struct sysv_inode * raw_inode; int i = 0, ino; ino = SYSV_ROOT_INO+1; raw_inode = sysv_raw_inode(sb, ino, &bh); if (!raw_inode) goto out; while (ino <= sbi->s_ninodes) { if (raw_inode->i_mode == 0 && raw_inode->i_nlink == 0) { *sv_sb_fic_inode(sb,i++) = cpu_to_fs16(SYSV_SB(sb), ino); if (i == sbi->s_fic_size) break; } if ((ino++ & sbi->s_inodes_per_block_1) == 0) { brelse(bh); raw_inode = sysv_raw_inode(sb, ino, &bh); if (!raw_inode) goto out; } else raw_inode++; } brelse(bh); out: return i; } void sysv_free_inode(struct inode * inode) { struct super_block *sb = inode->i_sb; struct sysv_sb_info *sbi = SYSV_SB(sb); unsigned int ino; struct buffer_head * bh; struct sysv_inode * raw_inode; unsigned count; sb = inode->i_sb; ino = inode->i_ino; if (ino <= SYSV_ROOT_INO || ino > sbi->s_ninodes) { printk("sysv_free_inode: inode 0,1,2 or nonexistent inode\n"); return; } raw_inode = sysv_raw_inode(sb, ino, &bh); if (!raw_inode) { printk("sysv_free_inode: unable to read inode block on device " "%s\n", inode->i_sb->s_id); return; } mutex_lock(&sbi->s_lock); count = fs16_to_cpu(sbi, *sbi->s_sb_fic_count); if (count < sbi->s_fic_size) { *sv_sb_fic_inode(sb,count++) = cpu_to_fs16(sbi, ino); *sbi->s_sb_fic_count = cpu_to_fs16(sbi, count); } fs16_add(sbi, sbi->s_sb_total_free_inodes, 1); dirty_sb(sb); memset(raw_inode, 0, sizeof(struct sysv_inode)); mark_buffer_dirty(bh); mutex_unlock(&sbi->s_lock); brelse(bh); } struct inode * sysv_new_inode(const struct inode * dir, umode_t mode) { struct super_block *sb = dir->i_sb; struct sysv_sb_info *sbi = SYSV_SB(sb); struct inode *inode; sysv_ino_t ino; unsigned count; struct writeback_control wbc = { .sync_mode = WB_SYNC_NONE }; inode = new_inode(sb); if (!inode) return ERR_PTR(-ENOMEM); mutex_lock(&sbi->s_lock); count = fs16_to_cpu(sbi, *sbi->s_sb_fic_count); if (count == 0 || (*sv_sb_fic_inode(sb,count-1) == 0)) { count = refill_free_cache(sb); if (count == 0) { iput(inode); mutex_unlock(&sbi->s_lock); return ERR_PTR(-ENOSPC); } } /* Now count > 0. */ ino = *sv_sb_fic_inode(sb,--count); *sbi->s_sb_fic_count = cpu_to_fs16(sbi, count); fs16_add(sbi, sbi->s_sb_total_free_inodes, -1); dirty_sb(sb); inode_init_owner(inode, dir, mode); inode->i_ino = fs16_to_cpu(sbi, ino); inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); inode->i_blocks = 0; memset(SYSV_I(inode)->i_data, 0, sizeof(SYSV_I(inode)->i_data)); SYSV_I(inode)->i_dir_start_lookup = 0; insert_inode_hash(inode); mark_inode_dirty(inode); sysv_write_inode(inode, &wbc); /* ensure inode not allocated again */ mark_inode_dirty(inode); /* cleared by sysv_write_inode() */ /* That's it. */ mutex_unlock(&sbi->s_lock); return inode; } unsigned long sysv_count_free_inodes(struct super_block * sb) { struct sysv_sb_info *sbi = SYSV_SB(sb); struct buffer_head * bh; struct sysv_inode * raw_inode; int ino, count, sb_count; mutex_lock(&sbi->s_lock); sb_count = fs16_to_cpu(sbi, *sbi->s_sb_total_free_inodes); if (0) goto trust_sb; /* this causes a lot of disk traffic ... */ count = 0; ino = SYSV_ROOT_INO+1; raw_inode = sysv_raw_inode(sb, ino, &bh); if (!raw_inode) goto Eio; while (ino <= sbi->s_ninodes) { if (raw_inode->i_mode == 0 && raw_inode->i_nlink == 0) count++; if ((ino++ & sbi->s_inodes_per_block_1) == 0) { brelse(bh); raw_inode = sysv_raw_inode(sb, ino, &bh); if (!raw_inode) goto Eio; } else raw_inode++; } brelse(bh); if (count != sb_count) goto Einval; out: mutex_unlock(&sbi->s_lock); return count; Einval: printk("sysv_count_free_inodes: " "free inode count was %d, correcting to %d\n", sb_count, count); if (!(sb->s_flags & MS_RDONLY)) { *sbi->s_sb_total_free_inodes = cpu_to_fs16(SYSV_SB(sb), count); dirty_sb(sb); } goto out; Eio: printk("sysv_count_free_inodes: unable to read inode table\n"); trust_sb: count = sb_count; goto out; } sound/synth/Makefile parent2c5d9555d6d937966d79d4c6529a5f7b9206e405 (diff)
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt() call in intel_unpin_fb_obj() returns NULL, resulting in an oops immediately afterwards as the (inlined) call to i915_vma_unpin_fence() tries to dereference it. It seems to be some race condition where the object is going away at shutdown time, since both times happened when shutting down the X server. The call chains were different: - VT ioctl(KDSETMODE, KD_TEXT): intel_cleanup_plane_fb+0x5b/0xa0 [i915] drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper] intel_atomic_commit_tail+0x749/0xfe0 [i915] intel_atomic_commit+0x3cb/0x4f0 [i915] drm_atomic_commit+0x4b/0x50 [drm] restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper] drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper] intel_fbdev_set_par+0x18/0x70 [i915] fb_set_var+0x236/0x460 fbcon_blank+0x30f/0x350 do_unblank_screen+0xd2/0x1a0 vt_ioctl+0x507/0x12a0 tty_ioctl+0x355/0xc30 do_vfs_ioctl+0xa3/0x5e0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x13/0x94 - i915 unpin_work workqueue: intel_unpin_work_fn+0x58/0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'sound/synth/Makefile')