From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- fs/gfs2/trans.c | 362 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 362 insertions(+) create mode 100644 fs/gfs2/trans.c (limited to 'fs/gfs2/trans.c') diff --git a/fs/gfs2/trans.c b/fs/gfs2/trans.c new file mode 100644 index 000000000..65cbe06e3 --- /dev/null +++ b/fs/gfs2/trans.c @@ -0,0 +1,362 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include + +#include "gfs2.h" +#include "incore.h" +#include "glock.h" +#include "inode.h" +#include "log.h" +#include "lops.h" +#include "meta_io.h" +#include "trans.h" +#include "util.h" +#include "trace_gfs2.h" + +static void gfs2_print_trans(struct gfs2_sbd *sdp, const struct gfs2_trans *tr) +{ + fs_warn(sdp, "Transaction created at: %pSR\n", (void *)tr->tr_ip); + fs_warn(sdp, "blocks=%u revokes=%u reserved=%u touched=%u\n", + tr->tr_blocks, tr->tr_revokes, tr->tr_reserved, + test_bit(TR_TOUCHED, &tr->tr_flags)); + fs_warn(sdp, "Buf %u/%u Databuf %u/%u Revoke %u\n", + tr->tr_num_buf_new, tr->tr_num_buf_rm, + tr->tr_num_databuf_new, tr->tr_num_databuf_rm, + tr->tr_num_revoke); +} + +int __gfs2_trans_begin(struct gfs2_trans *tr, struct gfs2_sbd *sdp, + unsigned int blocks, unsigned int revokes, + unsigned long ip) +{ + unsigned int extra_revokes; + + if (current->journal_info) { + gfs2_print_trans(sdp, current->journal_info); + BUG(); + } + BUG_ON(blocks == 0 && revokes == 0); + + if (gfs2_withdrawn(sdp)) + return -EROFS; + + tr->tr_ip = ip; + tr->tr_blocks = blocks; + tr->tr_revokes = revokes; + tr->tr_reserved = GFS2_LOG_FLUSH_MIN_BLOCKS; + if (blocks) { + /* + * The reserved blocks are either used for data or metadata. + * We can have mixed data and metadata, each with its own log + * descriptor block; see calc_reserved(). + */ + tr->tr_reserved += blocks + 1 + DIV_ROUND_UP(blocks - 1, databuf_limit(sdp)); + } + INIT_LIST_HEAD(&tr->tr_databuf); + INIT_LIST_HEAD(&tr->tr_buf); + INIT_LIST_HEAD(&tr->tr_list); + INIT_LIST_HEAD(&tr->tr_ail1_list); + INIT_LIST_HEAD(&tr->tr_ail2_list); + + if (gfs2_assert_warn(sdp, tr->tr_reserved <= sdp->sd_jdesc->jd_blocks)) + return -EINVAL; + + sb_start_intwrite(sdp->sd_vfs); + + /* + * Try the reservations under sd_log_flush_lock to prevent log flushes + * from creating inconsistencies between the number of allocated and + * reserved revokes. If that fails, do a full-block allocation outside + * of the lock to avoid stalling log flushes. Then, allot the + * appropriate number of blocks to revokes, use as many revokes locally + * as needed, and "release" the surplus into the revokes pool. + */ + + down_read(&sdp->sd_log_flush_lock); + if (unlikely(!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))) + goto out_not_live; + if (gfs2_log_try_reserve(sdp, tr, &extra_revokes)) + goto reserved; + + up_read(&sdp->sd_log_flush_lock); + gfs2_log_reserve(sdp, tr, &extra_revokes); + down_read(&sdp->sd_log_flush_lock); + if (unlikely(!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))) { + revokes = tr->tr_revokes + extra_revokes; + gfs2_log_release_revokes(sdp, revokes); + gfs2_log_release(sdp, tr->tr_reserved); + goto out_not_live; + } + +reserved: + gfs2_log_release_revokes(sdp, extra_revokes); + current->journal_info = tr; + return 0; + +out_not_live: + up_read(&sdp->sd_log_flush_lock); + sb_end_intwrite(sdp->sd_vfs); + return -EROFS; +} + +int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks, + unsigned int revokes) +{ + struct gfs2_trans *tr; + int error; + + tr = kmem_cache_zalloc(gfs2_trans_cachep, GFP_NOFS); + if (!tr) + return -ENOMEM; + error = __gfs2_trans_begin(tr, sdp, blocks, revokes, _RET_IP_); + if (error) + kmem_cache_free(gfs2_trans_cachep, tr); + return error; +} + +void gfs2_trans_end(struct gfs2_sbd *sdp) +{ + struct gfs2_trans *tr = current->journal_info; + s64 nbuf; + + current->journal_info = NULL; + + if (!test_bit(TR_TOUCHED, &tr->tr_flags)) { + gfs2_log_release_revokes(sdp, tr->tr_revokes); + up_read(&sdp->sd_log_flush_lock); + gfs2_log_release(sdp, tr->tr_reserved); + if (!test_bit(TR_ONSTACK, &tr->tr_flags)) + gfs2_trans_free(sdp, tr); + sb_end_intwrite(sdp->sd_vfs); + return; + } + + gfs2_log_release_revokes(sdp, tr->tr_revokes - tr->tr_num_revoke); + + nbuf = tr->tr_num_buf_new + tr->tr_num_databuf_new; + nbuf -= tr->tr_num_buf_rm; + nbuf -= tr->tr_num_databuf_rm; + + if (gfs2_assert_withdraw(sdp, nbuf <= tr->tr_blocks) || + gfs2_assert_withdraw(sdp, tr->tr_num_revoke <= tr->tr_revokes)) + gfs2_print_trans(sdp, tr); + + gfs2_log_commit(sdp, tr); + if (!test_bit(TR_ONSTACK, &tr->tr_flags) && + !test_bit(TR_ATTACHED, &tr->tr_flags)) + gfs2_trans_free(sdp, tr); + up_read(&sdp->sd_log_flush_lock); + + if (sdp->sd_vfs->s_flags & SB_SYNCHRONOUS) + gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL | + GFS2_LFC_TRANS_END); + sb_end_intwrite(sdp->sd_vfs); +} + +static struct gfs2_bufdata *gfs2_alloc_bufdata(struct gfs2_glock *gl, + struct buffer_head *bh) +{ + struct gfs2_bufdata *bd; + + bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL); + bd->bd_bh = bh; + bd->bd_gl = gl; + INIT_LIST_HEAD(&bd->bd_list); + INIT_LIST_HEAD(&bd->bd_ail_st_list); + INIT_LIST_HEAD(&bd->bd_ail_gl_list); + return bd; +} + +/** + * gfs2_trans_add_data - Add a databuf to the transaction. + * @gl: The inode glock associated with the buffer + * @bh: The buffer to add + * + * This is used in journaled data mode. + * We need to journal the data block in the same way as metadata in + * the functions above. The difference is that here we have a tag + * which is two __be64's being the block number (as per meta data) + * and a flag which says whether the data block needs escaping or + * not. This means we need a new log entry for each 251 or so data + * blocks, which isn't an enormous overhead but twice as much as + * for normal metadata blocks. + */ +void gfs2_trans_add_data(struct gfs2_glock *gl, struct buffer_head *bh) +{ + struct gfs2_trans *tr = current->journal_info; + struct gfs2_sbd *sdp = glock_sbd(gl); + struct gfs2_bufdata *bd; + + lock_buffer(bh); + if (buffer_pinned(bh)) { + set_bit(TR_TOUCHED, &tr->tr_flags); + goto out; + } + spin_lock(&sdp->sd_log_lock); + bd = bh->b_private; + if (bd == NULL) { + spin_unlock(&sdp->sd_log_lock); + unlock_buffer(bh); + bd = gfs2_alloc_bufdata(gl, bh); + lock_buffer(bh); + spin_lock(&sdp->sd_log_lock); + if (bh->b_private) { + kmem_cache_free(gfs2_bufdata_cachep, bd); + bd = bh->b_private; + } else { + bh->b_private = bd; + } + } + gfs2_assert(sdp, bd->bd_gl == gl); + set_bit(TR_TOUCHED, &tr->tr_flags); + if (list_empty(&bd->bd_list)) { + set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags); + set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags); + gfs2_pin(sdp, bd->bd_bh); + tr->tr_num_databuf_new++; + list_add_tail(&bd->bd_list, &tr->tr_databuf); + } + spin_unlock(&sdp->sd_log_lock); +out: + unlock_buffer(bh); +} + +void gfs2_trans_add_databufs(struct gfs2_glock *gl, struct folio *folio, + size_t from, size_t len) +{ + struct buffer_head *head = folio_buffers(folio); + unsigned int bsize = head->b_size; + struct buffer_head *bh; + size_t to = from + len; + size_t start, end; + + for (bh = head, start = 0; bh != head || !start; + bh = bh->b_this_page, start = end) { + end = start + bsize; + if (end <= from) + continue; + if (start >= to) + break; + set_buffer_uptodate(bh); + gfs2_trans_add_data(gl, bh); + } +} + +void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh) +{ + + struct gfs2_sbd *sdp = glock_sbd(gl); + struct super_block *sb = sdp->sd_vfs; + struct gfs2_bufdata *bd; + struct gfs2_meta_header *mh; + struct gfs2_trans *tr = current->journal_info; + + lock_buffer(bh); + if (buffer_pinned(bh)) { + set_bit(TR_TOUCHED, &tr->tr_flags); + goto out; + } + spin_lock(&sdp->sd_log_lock); + bd = bh->b_private; + if (bd == NULL) { + spin_unlock(&sdp->sd_log_lock); + unlock_buffer(bh); + bd = gfs2_alloc_bufdata(gl, bh); + lock_buffer(bh); + spin_lock(&sdp->sd_log_lock); + if (bh->b_private) { + kmem_cache_free(gfs2_bufdata_cachep, bd); + bd = bh->b_private; + } else { + bh->b_private = bd; + } + } + gfs2_assert(sdp, bd->bd_gl == gl); + set_bit(TR_TOUCHED, &tr->tr_flags); + if (!list_empty(&bd->bd_list)) + goto out_unlock; + set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags); + set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags); + mh = (struct gfs2_meta_header *)bd->bd_bh->b_data; + if (unlikely(mh->mh_magic != cpu_to_be32(GFS2_MAGIC))) { + fs_err(sdp, "Attempting to add uninitialised block to " + "journal (inplace block=%lld)\n", + (unsigned long long)bd->bd_bh->b_blocknr); + BUG(); + } + if (gfs2_withdrawn(sdp)) { + fs_info(sdp, "GFS2:adding buf while withdrawn! 0x%llx\n", + (unsigned long long)bd->bd_bh->b_blocknr); + goto out_unlock; + } + if (unlikely(sb->s_writers.frozen == SB_FREEZE_COMPLETE)) { + fs_info(sdp, "GFS2:adding buf while frozen\n"); + gfs2_withdraw(sdp); + goto out_unlock; + } + gfs2_pin(sdp, bd->bd_bh); + mh->__pad0 = cpu_to_be64(0); + mh->mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid); + list_add(&bd->bd_list, &tr->tr_buf); + tr->tr_num_buf_new++; +out_unlock: + spin_unlock(&sdp->sd_log_lock); +out: + unlock_buffer(bh); +} + +void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd) +{ + struct gfs2_trans *tr = current->journal_info; + + BUG_ON(!list_empty(&bd->bd_list)); + gfs2_add_revoke(sdp, bd); + set_bit(TR_TOUCHED, &tr->tr_flags); + tr->tr_num_revoke++; +} + +void gfs2_trans_remove_revoke(struct gfs2_sbd *sdp, u64 blkno, unsigned int len) +{ + struct gfs2_bufdata *bd, *tmp; + unsigned int n = len; + + spin_lock(&sdp->sd_log_lock); + list_for_each_entry_safe(bd, tmp, &sdp->sd_log_revokes, bd_list) { + if ((bd->bd_blkno >= blkno) && (bd->bd_blkno < (blkno + len))) { + list_del_init(&bd->bd_list); + gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke); + sdp->sd_log_num_revoke--; + if (bd->bd_gl) + gfs2_glock_remove_revoke(bd->bd_gl); + kmem_cache_free(gfs2_bufdata_cachep, bd); + gfs2_log_release_revokes(sdp, 1); + if (--n == 0) + break; + } + } + spin_unlock(&sdp->sd_log_lock); +} + +void gfs2_trans_free(struct gfs2_sbd *sdp, struct gfs2_trans *tr) +{ + if (tr == NULL) + return; + + gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list)); + gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list)); + gfs2_assert_warn(sdp, list_empty(&tr->tr_databuf)); + gfs2_assert_warn(sdp, list_empty(&tr->tr_buf)); + kmem_cache_free(gfs2_trans_cachep, tr); +} -- cgit v1.3.1