diff options
Diffstat (limited to 'fs')
-rw-r--r-- | fs/erofs/compress.h | 5 | ||||
-rw-r--r-- | fs/erofs/decompressor.c | 5 | ||||
-rw-r--r-- | fs/erofs/decompressor_deflate.c | 19 | ||||
-rw-r--r-- | fs/erofs/decompressor_lzma.c | 17 | ||||
-rw-r--r-- | fs/erofs/fscache.c | 2 | ||||
-rw-r--r-- | fs/erofs/inode.c | 2 | ||||
-rw-r--r-- | fs/erofs/utils.c | 2 | ||||
-rw-r--r-- | fs/erofs/zdata.c | 98 | ||||
-rw-r--r-- | fs/exfat/inode.c | 7 | ||||
-rw-r--r-- | fs/gfs2/dentry.c | 23 | ||||
-rw-r--r-- | fs/gfs2/inode.c | 8 | ||||
-rw-r--r-- | fs/hugetlbfs/inode.c | 2 | ||||
-rw-r--r-- | fs/jfs/jfs_dmap.c | 8 | ||||
-rw-r--r-- | fs/tracefs/event_inode.c | 606 | ||||
-rw-r--r-- | fs/tracefs/inode.c | 102 | ||||
-rw-r--r-- | fs/tracefs/internal.h | 44 |
16 files changed, 296 insertions, 654 deletions
diff --git a/fs/erofs/compress.h b/fs/erofs/compress.h index 279933e007d2..7cc5841577b2 100644 --- a/fs/erofs/compress.h +++ b/fs/erofs/compress.h @@ -11,13 +11,12 @@ struct z_erofs_decompress_req { struct super_block *sb; struct page **in, **out; - unsigned short pageofs_in, pageofs_out; unsigned int inputsize, outputsize; - /* indicate the algorithm will be used for decompression */ - unsigned int alg; + unsigned int alg; /* the algorithm for decompression */ bool inplace_io, partial_decoding, fillgaps; + gfp_t gfp; /* allocation flags for extra temporary buffers */ }; struct z_erofs_decompressor { diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index 072ef6a66823..d4cee95af14c 100644 --- a/fs/erofs/decompressor.c +++ b/fs/erofs/decompressor.c @@ -111,8 +111,9 @@ static int z_erofs_lz4_prepare_dstpages(struct z_erofs_lz4_decompress_ctx *ctx, victim = availables[--top]; get_page(victim); } else { - victim = erofs_allocpage(pagepool, - GFP_KERNEL | __GFP_NOFAIL); + victim = erofs_allocpage(pagepool, rq->gfp); + if (!victim) + return -ENOMEM; set_page_private(victim, Z_EROFS_SHORTLIVED_PAGE); } rq->out[i] = victim; diff --git a/fs/erofs/decompressor_deflate.c b/fs/erofs/decompressor_deflate.c index 4a64a9c91dd3..b98872058abe 100644 --- a/fs/erofs/decompressor_deflate.c +++ b/fs/erofs/decompressor_deflate.c @@ -95,7 +95,7 @@ int z_erofs_load_deflate_config(struct super_block *sb, } int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq, - struct page **pagepool) + struct page **pgpl) { const unsigned int nrpages_out = PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT; @@ -158,8 +158,12 @@ again: strm->z.avail_out = min_t(u32, outsz, PAGE_SIZE - pofs); outsz -= strm->z.avail_out; if (!rq->out[no]) { - rq->out[no] = erofs_allocpage(pagepool, - GFP_KERNEL | __GFP_NOFAIL); + rq->out[no] = erofs_allocpage(pgpl, rq->gfp); + if (!rq->out[no]) { + kout = NULL; + err = -ENOMEM; + break; + } set_page_private(rq->out[no], Z_EROFS_SHORTLIVED_PAGE); } @@ -211,8 +215,11 @@ again: DBG_BUGON(erofs_page_is_managed(EROFS_SB(sb), rq->in[j])); - tmppage = erofs_allocpage(pagepool, - GFP_KERNEL | __GFP_NOFAIL); + tmppage = erofs_allocpage(pgpl, rq->gfp); + if (!tmppage) { + err = -ENOMEM; + goto failed; + } set_page_private(tmppage, Z_EROFS_SHORTLIVED_PAGE); copy_highpage(tmppage, rq->in[j]); rq->in[j] = tmppage; @@ -230,7 +237,7 @@ again: break; } } - +failed: if (zlib_inflateEnd(&strm->z) != Z_OK && !err) err = -EIO; if (kout) diff --git a/fs/erofs/decompressor_lzma.c b/fs/erofs/decompressor_lzma.c index 2dd14f99c1dc..6ca357d83cfa 100644 --- a/fs/erofs/decompressor_lzma.c +++ b/fs/erofs/decompressor_lzma.c @@ -148,7 +148,7 @@ again: } int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq, - struct page **pagepool) + struct page **pgpl) { const unsigned int nrpages_out = PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT; @@ -215,8 +215,11 @@ again: PAGE_SIZE - pageofs); outlen -= strm->buf.out_size; if (!rq->out[no] && rq->fillgaps) { /* deduped */ - rq->out[no] = erofs_allocpage(pagepool, - GFP_KERNEL | __GFP_NOFAIL); + rq->out[no] = erofs_allocpage(pgpl, rq->gfp); + if (!rq->out[no]) { + err = -ENOMEM; + break; + } set_page_private(rq->out[no], Z_EROFS_SHORTLIVED_PAGE); } @@ -258,8 +261,11 @@ again: DBG_BUGON(erofs_page_is_managed(EROFS_SB(rq->sb), rq->in[j])); - tmppage = erofs_allocpage(pagepool, - GFP_KERNEL | __GFP_NOFAIL); + tmppage = erofs_allocpage(pgpl, rq->gfp); + if (!tmppage) { + err = -ENOMEM; + goto failed; + } set_page_private(tmppage, Z_EROFS_SHORTLIVED_PAGE); copy_highpage(tmppage, rq->in[j]); rq->in[j] = tmppage; @@ -277,6 +283,7 @@ again: break; } } +failed: if (no < nrpages_out && strm->buf.out) kunmap(rq->out[no]); if (ni < nrpages_in) diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c index bc12030393b2..5ff90026fd43 100644 --- a/fs/erofs/fscache.c +++ b/fs/erofs/fscache.c @@ -459,7 +459,7 @@ static struct erofs_fscache *erofs_fscache_acquire_cookie(struct super_block *sb inode->i_size = OFFSET_MAX; inode->i_mapping->a_ops = &erofs_fscache_meta_aops; - mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS); + mapping_set_gfp_mask(inode->i_mapping, GFP_KERNEL); inode->i_blkbits = EROFS_SB(sb)->blkszbits; inode->i_private = ctx; diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c index 3d616dea55dc..36e638e8b53a 100644 --- a/fs/erofs/inode.c +++ b/fs/erofs/inode.c @@ -60,7 +60,7 @@ static void *erofs_read_inode(struct erofs_buf *buf, } else { const unsigned int gotten = sb->s_blocksize - *ofs; - copied = kmalloc(vi->inode_isize, GFP_NOFS); + copied = kmalloc(vi->inode_isize, GFP_KERNEL); if (!copied) { err = -ENOMEM; goto err_out; diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c index 5dea308764b4..e146d09151af 100644 --- a/fs/erofs/utils.c +++ b/fs/erofs/utils.c @@ -81,7 +81,7 @@ struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb, repeat: xa_lock(&sbi->managed_pslots); pre = __xa_cmpxchg(&sbi->managed_pslots, grp->index, - NULL, grp, GFP_NOFS); + NULL, grp, GFP_KERNEL); if (pre) { if (xa_is_err(pre)) { pre = ERR_PTR(xa_err(pre)); diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index 692c0c39be63..ff0aa72b0db3 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -82,6 +82,9 @@ struct z_erofs_pcluster { /* L: indicate several pageofs_outs or not */ bool multibases; + /* L: whether extra buffer allocations are best-effort */ + bool besteffort; + /* A: compressed bvecs (can be cached or inplaced pages) */ struct z_erofs_bvec compressed_bvecs[]; }; @@ -230,7 +233,7 @@ static int z_erofs_bvec_enqueue(struct z_erofs_bvec_iter *iter, struct page *nextpage = *candidate_bvpage; if (!nextpage) { - nextpage = erofs_allocpage(pagepool, GFP_NOFS); + nextpage = erofs_allocpage(pagepool, GFP_KERNEL); if (!nextpage) return -ENOMEM; set_page_private(nextpage, Z_EROFS_SHORTLIVED_PAGE); @@ -302,7 +305,7 @@ static struct z_erofs_pcluster *z_erofs_alloc_pcluster(unsigned int size) if (nrpages > pcs->maxpages) continue; - pcl = kmem_cache_zalloc(pcs->slab, GFP_NOFS); + pcl = kmem_cache_zalloc(pcs->slab, GFP_KERNEL); if (!pcl) return ERR_PTR(-ENOMEM); pcl->pclustersize = size; @@ -563,21 +566,19 @@ static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe) __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; unsigned int i; - if (i_blocksize(fe->inode) != PAGE_SIZE) - return; - if (fe->mode < Z_EROFS_PCLUSTER_FOLLOWED) + if (i_blocksize(fe->inode) != PAGE_SIZE || + fe->mode < Z_EROFS_PCLUSTER_FOLLOWED) return; for (i = 0; i < pclusterpages; ++i) { struct page *page, *newpage; void *t; /* mark pages just found for debugging */ - /* the compressed page was loaded before */ + /* Inaccurate check w/o locking to avoid unneeded lookups */ if (READ_ONCE(pcl->compressed_bvecs[i].page)) continue; page = find_get_page(mc, pcl->obj.index + i); - if (page) { t = (void *)((unsigned long)page | 1); newpage = NULL; @@ -597,9 +598,13 @@ static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe) set_page_private(newpage, Z_EROFS_PREALLOCATED_PAGE); t = (void *)((unsigned long)newpage | 1); } - - if (!cmpxchg_relaxed(&pcl->compressed_bvecs[i].page, NULL, t)) + spin_lock(&pcl->obj.lockref.lock); + if (!pcl->compressed_bvecs[i].page) { + pcl->compressed_bvecs[i].page = t; + spin_unlock(&pcl->obj.lockref.lock); continue; + } + spin_unlock(&pcl->obj.lockref.lock); if (page) put_page(page); @@ -694,7 +699,7 @@ static void z_erofs_cache_invalidate_folio(struct folio *folio, DBG_BUGON(stop > folio_size(folio) || stop < length); if (offset == 0 && stop == folio_size(folio)) - while (!z_erofs_cache_release_folio(folio, GFP_NOFS)) + while (!z_erofs_cache_release_folio(folio, 0)) cond_resched(); } @@ -713,36 +718,30 @@ int erofs_init_managed_cache(struct super_block *sb) set_nlink(inode, 1); inode->i_size = OFFSET_MAX; inode->i_mapping->a_ops = &z_erofs_cache_aops; - mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS); + mapping_set_gfp_mask(inode->i_mapping, GFP_KERNEL); EROFS_SB(sb)->managed_cache = inode; return 0; } -static bool z_erofs_try_inplace_io(struct z_erofs_decompress_frontend *fe, - struct z_erofs_bvec *bvec) -{ - struct z_erofs_pcluster *const pcl = fe->pcl; - - while (fe->icur > 0) { - if (!cmpxchg(&pcl->compressed_bvecs[--fe->icur].page, - NULL, bvec->page)) { - pcl->compressed_bvecs[fe->icur] = *bvec; - return true; - } - } - return false; -} - /* callers must be with pcluster lock held */ static int z_erofs_attach_page(struct z_erofs_decompress_frontend *fe, struct z_erofs_bvec *bvec, bool exclusive) { + struct z_erofs_pcluster *pcl = fe->pcl; int ret; if (exclusive) { /* give priority for inplaceio to use file pages first */ - if (z_erofs_try_inplace_io(fe, bvec)) + spin_lock(&pcl->obj.lockref.lock); + while (fe->icur > 0) { + if (pcl->compressed_bvecs[--fe->icur].page) + continue; + pcl->compressed_bvecs[fe->icur] = *bvec; + spin_unlock(&pcl->obj.lockref.lock); return 0; + } + spin_unlock(&pcl->obj.lockref.lock); + /* otherwise, check if it can be used as a bvpage */ if (fe->mode >= Z_EROFS_PCLUSTER_FOLLOWED && !fe->candidate_bvpage) @@ -964,7 +963,7 @@ static int z_erofs_read_fragment(struct super_block *sb, struct page *page, } static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe, - struct page *page) + struct page *page, bool ra) { struct inode *const inode = fe->inode; struct erofs_map_blocks *const map = &fe->map; @@ -1014,6 +1013,7 @@ repeat: err = z_erofs_pcluster_begin(fe); if (err) goto out; + fe->pcl->besteffort |= !ra; } /* @@ -1280,6 +1280,9 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be, .inplace_io = overlapped, .partial_decoding = pcl->partial, .fillgaps = pcl->multibases, + .gfp = pcl->besteffort ? + GFP_KERNEL | __GFP_NOFAIL : + GFP_NOWAIT | __GFP_NORETRY }, be->pagepool); /* must handle all compressed pages before actual file pages */ @@ -1322,6 +1325,7 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be, pcl->length = 0; pcl->partial = true; pcl->multibases = false; + pcl->besteffort = false; pcl->bvset.nextpage = NULL; pcl->vcnt = 0; @@ -1423,23 +1427,26 @@ static void z_erofs_fill_bio_vec(struct bio_vec *bvec, { gfp_t gfp = mapping_gfp_mask(mc); bool tocache = false; - struct z_erofs_bvec *zbv = pcl->compressed_bvecs + nr; + struct z_erofs_bvec zbv; struct address_space *mapping; - struct page *page, *oldpage; + struct page *page; int justfound, bs = i_blocksize(f->inode); /* Except for inplace pages, the entire page can be used for I/Os */ bvec->bv_offset = 0; bvec->bv_len = PAGE_SIZE; repeat: - oldpage = READ_ONCE(zbv->page); - if (!oldpage) + spin_lock(&pcl->obj.lockref.lock); + zbv = pcl->compressed_bvecs[nr]; + page = zbv.page; + justfound = (unsigned long)page & 1UL; + page = (struct page *)((unsigned long)page & ~1UL); + pcl->compressed_bvecs[nr].page = page; + spin_unlock(&pcl->obj.lockref.lock); + if (!page) goto out_allocpage; - justfound = (unsigned long)oldpage & 1UL; - page = (struct page *)((unsigned long)oldpage & ~1UL); bvec->bv_page = page; - DBG_BUGON(z_erofs_is_shortlived_page(page)); /* * Handle preallocated cached pages. We tried to allocate such pages @@ -1448,7 +1455,6 @@ repeat: */ if (page->private == Z_EROFS_PREALLOCATED_PAGE) { set_page_private(page, 0); - WRITE_ONCE(zbv->page, page); tocache = true; goto out_tocache; } @@ -1459,9 +1465,9 @@ repeat: * therefore it is impossible for `mapping` to be NULL. */ if (mapping && mapping != mc) { - if (zbv->offset < 0) - bvec->bv_offset = round_up(-zbv->offset, bs); - bvec->bv_len = round_up(zbv->end, bs) - bvec->bv_offset; + if (zbv.offset < 0) + bvec->bv_offset = round_up(-zbv.offset, bs); + bvec->bv_len = round_up(zbv.end, bs) - bvec->bv_offset; return; } @@ -1471,7 +1477,6 @@ repeat: /* the cached page is still in managed cache */ if (page->mapping == mc) { - WRITE_ONCE(zbv->page, page); /* * The cached page is still available but without a valid * `->private` pcluster hint. Let's reconnect them. @@ -1503,11 +1508,15 @@ repeat: put_page(page); out_allocpage: page = erofs_allocpage(&f->pagepool, gfp | __GFP_NOFAIL); - if (oldpage != cmpxchg(&zbv->page, oldpage, page)) { + spin_lock(&pcl->obj.lockref.lock); + if (pcl->compressed_bvecs[nr].page) { erofs_pagepool_add(&f->pagepool, page); + spin_unlock(&pcl->obj.lockref.lock); cond_resched(); goto repeat; } + pcl->compressed_bvecs[nr].page = page; + spin_unlock(&pcl->obj.lockref.lock); bvec->bv_page = page; out_tocache: if (!tocache || bs != PAGE_SIZE || @@ -1685,6 +1694,7 @@ submit_bio_retry: if (cur + bvec.bv_len > end) bvec.bv_len = end - cur; + DBG_BUGON(bvec.bv_len < sb->s_blocksize); if (!bio_add_page(bio, bvec.bv_page, bvec.bv_len, bvec.bv_offset)) goto submit_bio_retry; @@ -1785,7 +1795,7 @@ static void z_erofs_pcluster_readmore(struct z_erofs_decompress_frontend *f, if (PageUptodate(page)) unlock_page(page); else - (void)z_erofs_do_read_page(f, page); + (void)z_erofs_do_read_page(f, page, !!rac); put_page(page); } @@ -1806,7 +1816,7 @@ static int z_erofs_read_folio(struct file *file, struct folio *folio) f.headoffset = (erofs_off_t)folio->index << PAGE_SHIFT; z_erofs_pcluster_readmore(&f, NULL, true); - err = z_erofs_do_read_page(&f, &folio->page); + err = z_erofs_do_read_page(&f, &folio->page, false); z_erofs_pcluster_readmore(&f, NULL, false); z_erofs_pcluster_end(&f); @@ -1847,7 +1857,7 @@ static void z_erofs_readahead(struct readahead_control *rac) folio = head; head = folio_get_private(folio); - err = z_erofs_do_read_page(&f, &folio->page); + err = z_erofs_do_read_page(&f, &folio->page, true); if (err && err != -EINTR) erofs_err(inode->i_sb, "readahead error at folio %lu @ nid %llu", folio->index, EROFS_I(inode)->nid); diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c index 522edcbb2ce4..0687f952956c 100644 --- a/fs/exfat/inode.c +++ b/fs/exfat/inode.c @@ -501,7 +501,7 @@ static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) struct inode *inode = mapping->host; struct exfat_inode_info *ei = EXFAT_I(inode); loff_t pos = iocb->ki_pos; - loff_t size = iocb->ki_pos + iov_iter_count(iter); + loff_t size = pos + iov_iter_count(iter); int rw = iov_iter_rw(iter); ssize_t ret; @@ -525,11 +525,10 @@ static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) */ ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block); if (ret < 0) { - if (rw == WRITE) + if (rw == WRITE && ret != -EIOCBQUEUED) exfat_write_failed(mapping, size); - if (ret != -EIOCBQUEUED) - return ret; + return ret; } else size = pos + ret; diff --git a/fs/gfs2/dentry.c b/fs/gfs2/dentry.c index 177f1f41f225..2e215e8c3c88 100644 --- a/fs/gfs2/dentry.c +++ b/fs/gfs2/dentry.c @@ -32,25 +32,21 @@ static int gfs2_drevalidate(struct dentry *dentry, unsigned int flags) { - struct dentry *parent = NULL; + struct dentry *parent; struct gfs2_sbd *sdp; struct gfs2_inode *dip; - struct inode *dinode, *inode; + struct inode *inode; struct gfs2_holder d_gh; struct gfs2_inode *ip = NULL; int error, valid = 0; int had_lock = 0; - if (flags & LOOKUP_RCU) { - dinode = d_inode_rcu(READ_ONCE(dentry->d_parent)); - if (!dinode) - return -ECHILD; - } else { - parent = dget_parent(dentry); - dinode = d_inode(parent); - } - sdp = GFS2_SB(dinode); - dip = GFS2_I(dinode); + if (flags & LOOKUP_RCU) + return -ECHILD; + + parent = dget_parent(dentry); + sdp = GFS2_SB(d_inode(parent)); + dip = GFS2_I(d_inode(parent)); inode = d_inode(dentry); if (inode) { @@ -66,8 +62,7 @@ static int gfs2_drevalidate(struct dentry *dentry, unsigned int flags) had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL); if (!had_lock) { - error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, - flags & LOOKUP_RCU ? GL_NOBLOCK : 0, &d_gh); + error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh); if (error) goto out; } diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c index 6bfc9383b7b8..1b95db2c3aac 100644 --- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -1882,10 +1882,10 @@ int gfs2_permission(struct mnt_idmap *idmap, struct inode *inode, WARN_ON_ONCE(!may_not_block); return -ECHILD; } - if (gfs2_glock_is_locked_by_me(ip->i_gl) == NULL) { - int noblock = may_not_block ? GL_NOBLOCK : 0; - error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, - LM_FLAG_ANY | noblock, &i_gh); + if (gfs2_glock_is_locked_by_me(gl) == NULL) { + if (may_not_block) + return -ECHILD; + error = gfs2_glock_nq_init(gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); if (error) return error; } diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index ea5b8e57d904..671664fed307 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -340,7 +340,7 @@ static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to) } else { folio_unlock(folio); - if (!folio_test_has_hwpoisoned(folio)) + if (!folio_test_hwpoison(folio)) want = nr; else { /* diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index 8eec84c651bf..cb3cda1390ad 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -2763,9 +2763,7 @@ static int dbBackSplit(dmtree_t *tp, int leafno, bool is_ctl) * leafno - the number of the leaf to be updated. * newval - the new value for the leaf. * - * RETURN VALUES: - * 0 - success - * -EIO - i/o error + * RETURN VALUES: none */ static int dbJoin(dmtree_t *tp, int leafno, int newval, bool is_ctl) { @@ -2792,10 +2790,6 @@ static int dbJoin(dmtree_t *tp, int leafno, int newval, bool is_ctl) * get the buddy size (number of words covered) of * the new value. */ - - if ((newval - tp->dmt_budmin) > BUDMIN) - return -EIO; - budsz = BUDSIZE(newval, tp->dmt_budmin); /* try to join. diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 6b211522a13e..110e8a272189 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -62,6 +62,46 @@ enum { #define EVENTFS_MODE_MASK (EVENTFS_SAVE_MODE - 1) +/* + * eventfs_inode reference count management. + * + * NOTE! We count only references from dentries, in the + * form 'dentry->d_fsdata'. There are also references from + * directory inodes ('ti->private'), but the dentry reference + * count is always a superset of the inode reference count. + */ +static void release_ei(struct kref *ref) +{ + struct eventfs_inode *ei = container_of(ref, struct eventfs_inode, kref); + + WARN_ON_ONCE(!ei->is_freed); + + kfree(ei->entry_attrs); + kfree_const(ei->name); + kfree_rcu(ei, rcu); +} + +static inline void put_ei(struct eventfs_inode *ei) +{ + if (ei) + kref_put(&ei->kref, release_ei); +} + +static inline void free_ei(struct eventfs_inode *ei) +{ + if (ei) { + ei->is_freed = 1; + put_ei(ei); + } +} + +static inline struct eventfs_inode *get_ei(struct eventfs_inode *ei) +{ + if (ei) + kref_get(&ei->kref); + return ei; +} + static struct dentry *eventfs_root_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags); @@ -156,33 +196,30 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry, return ret; } -static void update_top_events_attr(struct eventfs_inode *ei, struct dentry *dentry) +static void update_top_events_attr(struct eventfs_inode *ei, struct super_block *sb) { - struct inode *inode; + struct inode *root; /* Only update if the "events" was on the top level */ if (!ei || !(ei->attr.mode & EVENTFS_TOPLEVEL)) return; /* Get the tracefs root inode. */ - inode = d_inode(dentry->d_sb->s_root); - ei->attr.uid = inode->i_uid; - ei->attr.gid = inode->i_gid; + root = d_inode(sb->s_root); + ei->attr.uid = root->i_uid; + ei->attr.gid = root->i_gid; } static void set_top_events_ownership(struct inode *inode) { struct tracefs_inode *ti = get_tracefs(inode); struct eventfs_inode *ei = ti->private; - struct dentry *dentry; /* The top events directory doesn't get automatically updated */ if (!ei || !ei->is_events || !(ei->attr.mode & EVENTFS_TOPLEVEL)) return; - dentry = ei->dentry; - - update_top_events_attr(ei, dentry); + update_top_events_attr(ei, inode->i_sb); if (!(ei->attr.mode & EVENTFS_SAVE_UID)) inode->i_uid = ei->attr.uid; @@ -233,10 +270,11 @@ static struct eventfs_inode *eventfs_find_events(struct dentry *dentry) { struct eventfs_inode *ei; - mutex_lock(&eventfs_mutex); do { - /* The parent always has an ei, except for events itself */ - ei = dentry->d_parent->d_fsdata; + // The parent is stable because we do not do renames + dentry = dentry->d_parent; + // ... and directories always have d_fsdata + ei = dentry->d_fsdata; /* * If the ei is being freed, the ownership of the children @@ -246,12 +284,10 @@ static struct eventfs_inode *eventfs_find_events(struct dentry *dentry) ei = NULL; break; } - - dentry = ei->dentry; + // Walk upwards until you find the events inode } while (!ei->is_events); - mutex_unlock(&eventfs_mutex); - update_top_events_attr(ei, dentry); + update_top_events_attr(ei, dentry->d_sb); return ei; } @@ -281,50 +317,11 @@ static void update_inode_attr(struct dentry *dentry, struct inode *inode, inode->i_gid = attr->gid; } -static void update_gid(struct eventfs_inode *ei, kgid_t gid, int level) -{ - struct eventfs_inode *ei_child; - - /* at most we have events/system/event */ - if (WARN_ON_ONCE(level > 3)) - return; - - ei->attr.gid = gid; - - if (ei->entry_attrs) { - for (int i = 0; i < ei->nr_entries; i++) { - ei->entry_attrs[i].gid = gid; - } - } - - /* - * Only eventfs_inode with dentries are updated, make sure - * all eventfs_inodes are updated. If one of the children - * do not have a dentry, this function must traverse it. - */ - list_for_each_entry_srcu(ei_child, &ei->children, list, - srcu_read_lock_held(&eventfs_srcu)) { - if (!ei_child->dentry) - update_gid(ei_child, gid, level + 1); - } -} - -void eventfs_update_gid(struct dentry *dentry, kgid_t gid) -{ - struct eventfs_inode *ei = dentry->d_fsdata; - int idx; - - idx = srcu_read_lock(&eventfs_srcu); - update_gid(ei, gid, 0); - srcu_read_unlock(&eventfs_srcu, idx); -} - /** - * create_file - create a file in the tracefs filesystem - * @name: the name of the file to create. + * lookup_file - look up a file in the tracefs filesystem + * @dentry: the dentry to look up * @mode: the permission that the file should have. * @attr: saved attributes changed by user - * @parent: parent dentry for this file. * @data: something that the caller will want to get to later on. * @fop: struct file_operations that should be used for this file. * @@ -332,30 +329,25 @@ void eventfs_update_gid(struct dentry *dentry, kgid_t gid) * directory. The inode.i_private pointer will point to @data in the open() * call. */ -static struct dentry *create_file(const char *name, umode_t mode, +static struct dentry *lookup_file(struct eventfs_inode *parent_ei, + struct dentry *dentry, + umode_t mode, struct eventfs_attr *attr, - struct dentry *parent, void *data, + void *data, const struct file_operations *fop) { struct tracefs_inode *ti; - struct dentry *dentry; struct inode *inode; if (!(mode & S_IFMT)) mode |= S_IFREG; if (WARN_ON_ONCE(!S_ISREG(mode))) - return NULL; - - WARN_ON_ONCE(!parent); - dentry = eventfs_start_creating(name, parent); - - if (IS_ERR(dentry)) - return dentry; + return ERR_PTR(-EIO); inode = tracefs_get_inode(dentry->d_sb); if (unlikely(!inode)) - return eventfs_failed_creating(dentry); + return ERR_PTR(-ENOMEM); /* If the user updated the directory's attributes, use them */ update_inode_attr(dentry, inode, attr, mode); @@ -369,32 +361,31 @@ static struct dentry *create_file(const char *name, umode_t mode, ti = get_tracefs(inode); ti->flags |= TRACEFS_EVENT_INODE; - d_instantiate(dentry, inode); - fsnotify_create(dentry->d_parent->d_inode, dentry); - return eventfs_end_creating(dentry); + + // Files have their parent's ei as their fsdata + dentry->d_fsdata = get_ei(parent_ei); + + d_add(dentry, inode); + return NULL; }; /** - * create_dir - create a dir in the tracefs filesystem + * lookup_dir_entry - look up a dir in the tracefs filesystem + * @dentry: the directory to look up * @ei: the eventfs_inode that represents the directory to create - * @parent: parent dentry for this file. * - * This function will create a dentry for a directory represented by + * This function will look up a dentry for a directory represented by * a eventfs_inode. */ -static struct dentry *create_dir(struct eventfs_inode *ei, struct dentry *parent) +static struct dentry *lookup_dir_entry(struct dentry *dentry, + struct eventfs_inode *pei, struct eventfs_inode *ei) { struct tracefs_inode *ti; - struct dentry *dentry; struct inode *inode; - dentry = eventfs_start_creating(ei->name, parent); - if (IS_ERR(dentry)) - return dentry; - inode = tracefs_get_inode(dentry->d_sb); if (unlikely(!inode)) - return eventfs_failed_creating(dentry); + return ERR_PTR(-ENOMEM); /* If the user updated the directory's attributes, use them */ update_inode_attr(dentry, inode, &ei->attr, @@ -408,64 +399,46 @@ static struct dentry *create_dir(struct eventfs_inode *ei, struct dentry *parent ti = get_tracefs(inode); ti->flags |= TRACEFS_EVENT_INODE; + /* Only directories have ti->private set to an ei, not files */ + ti->private = ei; - inc_nlink(inode); - d_instantiate(dentry, inode); - inc_nlink(dentry->d_parent->d_inode); - fsnotify_mkdir(dentry->d_parent->d_inode, dentry); - return eventfs_end_creating(dentry); + dentry->d_fsdata = get_ei(ei); + + d_add(dentry, inode); + return NULL; } -static void free_ei(struct eventfs_inode *ei) +static inline struct eventfs_inode *alloc_ei(const char *name) { - kfree_const(ei->name); - kfree(ei->d_children); - kfree(ei->entry_attrs); - kfree(ei); + struct eventfs_inode *ei = kzalloc(sizeof(*ei), GFP_KERNEL); + + if (!ei) + return NULL; + + ei->name = kstrdup_const(name, GFP_KERNEL); + if (!ei->name) { + kfree(ei); + return NULL; + } + kref_init(&ei->kref); + return ei; } /** - * eventfs_set_ei_status_free - remove the dentry reference from an eventfs_inode - * @ti: the tracefs_inode of the dentry + * eventfs_d_release - dentry is going away * @dentry: dentry which has the reference to remove. * * Remove the association between a dentry from an eventfs_inode. */ -void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry) +void eventfs_d_release(struct dentry *dentry) { - struct eventfs_inode *ei; - int i; - - mutex_lock(&eventfs_mutex); - - ei = dentry->d_fsdata; - if (!ei) - goto out; - - /* This could belong to one of the files of the ei */ - if (ei->dentry != dentry) { - for (i = 0; i < ei->nr_entries; i++) { - if (ei->d_children[i] == dentry) - break; - } - if (WARN_ON_ONCE(i == ei->nr_entries)) - goto out; - ei->d_children[i] = NULL; - } else if (ei->is_freed) { - free_ei(ei); - } else { - ei->dentry = NULL; - } - - dentry->d_fsdata = NULL; - out: - mutex_unlock(&eventfs_mutex); + put_ei(dentry->d_fsdata); } /** - * create_file_dentry - create a dentry for a file of an eventfs_inode + * lookup_file_dentry - create a dentry for a file of an eventfs_inode * @ei: the eventfs_inode that the file will be created under - * @idx: the index into the d_children[] of the @ei + * @idx: the index into the entry_attrs[] of the @ei * @parent: The parent dentry of the created file. * @name: The name of the file to create * @mode: The mode of the file. @@ -476,163 +449,17 @@ void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry) * address located at @e_dentry. */ static struct dentry * -create_file_dentry(struct eventfs_inode *ei, int idx, - struct dentry *parent, const char *name, umode_t mode, void *data, +lookup_file_dentry(struct dentry *dentry, + struct eventfs_inode *ei, int idx, + umode_t mode, void *data, const struct file_operations *fops) { struct eventfs_attr *attr = NULL; - struct dentry **e_dentry = &ei->d_children[idx]; - struct dentry *dentry; - - WARN_ON_ONCE(!inode_is_locked(parent->d_inode)); - mutex_lock(&eventfs_mutex); - if (ei->is_freed) { - mutex_unlock(&eventfs_mutex); - return NULL; - } - /* If the e_dentry already has a dentry, use it */ - if (*e_dentry) { - dget(*e_dentry); - mutex_unlock(&eventfs_mutex); - return *e_dentry; - } - - /* ei->entry_attrs are protected by SRCU */ if (ei->entry_attrs) attr = &ei->entry_attrs[idx]; - mutex_unlock(&eventfs_mutex); - - dentry = create_file(name, mode, attr, parent, data, fops); - - mutex_lock(&eventfs_mutex); - - if (IS_ERR_OR_NULL(dentry)) { - /* - * When the mutex was released, something else could have - * created the dentry for this e_dentry. In which case - * use that one. - * - * If ei->is_freed is set, the e_dentry is currently on its - * way to being freed, don't return it. If e_dentry is NULL - * it means it was already freed. - */ - if (ei->is_freed) { - dentry = NULL; - } else { - dentry = *e_dentry; - dget(dentry); - } - mutex_unlock(&eventfs_mutex); - return dentry; - } - - if (!*e_dentry && !ei->is_freed) { - *e_dentry = dentry; - dentry->d_fsdata = ei; - } else { - /* - * Should never happen unless we get here due to being freed. - * Otherwise it means two dentries exist with the same name. - */ - WARN_ON_ONCE(!ei->is_freed); - dentry = NULL; - } - mutex_unlock(&eventfs_mutex); - - return dentry; -} - -/** - * eventfs_post_create_dir - post create dir routine - * @ei: eventfs_inode of recently created dir - * - * Map the meta-data of files within an eventfs dir to their parent dentry - */ -static void eventfs_post_create_dir(struct eventfs_inode *ei) -{ - struct eventfs_inode *ei_child; - struct tracefs_inode *ti; - - lockdep_assert_held(&eventfs_mutex); - - /* srcu lock already held */ - /* fill parent-child relation */ - list_for_each_entry_srcu(ei_child, &ei->children, list, - srcu_read_lock_held(&eventfs_srcu)) { - ei_child->d_parent = ei->dentry; - } - - ti = get_tracefs(ei->dentry->d_inode); - ti->private = ei; -} - -/** - * create_dir_dentry - Create a directory dentry for the eventfs_inode - * @pei: The eventfs_inode parent of ei. - * @ei: The eventfs_inode to create the directory for - * @parent: The dentry of the parent of this directory - * - * This creates and attaches a directory dentry to the eventfs_inode @ei. - */ -static struct dentry * -create_dir_dentry(struct eventfs_inode *pei, struct eventfs_inode *ei, - struct dentry *parent) -{ - struct dentry *dentry = NULL; - - WARN_ON_ONCE(!inode_is_locked(parent->d_inode)); - - mutex_lock(&eventfs_mutex); - if (pei->is_freed || ei->is_freed) { - mutex_unlock(&eventfs_mutex); - return NULL; - } - if (ei->dentry) { - /* If the eventfs_inode already has a dentry, use it */ - dentry = ei->dentry; - dget(dentry); - mutex_unlock(&eventfs_mutex); - return dentry; - } - mutex_unlock(&eventfs_mutex); - - dentry = create_dir(ei, parent); - - mutex_lock(&eventfs_mutex); - - if (IS_ERR_OR_NULL(dentry) && !ei->is_freed) { - /* - * When the mutex was released, something else could have - * created the dentry for this e_dentry. In which case - * use that one. - * - * If ei->is_freed is set, the e_dentry is currently on its - * way to being freed. - */ - dentry = ei->dentry; - if (dentry) - dget(dentry); - mutex_unlock(&eventfs_mutex); - return dentry; - } - - if (!ei->dentry && !ei->is_freed) { - ei->dentry = dentry; - eventfs_post_create_dir(ei); - dentry->d_fsdata = ei; - } else { - /* - * Should never happen unless we get here due to being freed. - * Otherwise it means two dentries exist with the same name. - */ - WARN_ON_ONCE(!ei->is_freed); - dentry = NULL; - } - mutex_unlock(&eventfs_mutex); - - return dentry; + return lookup_file(ei, dentry, mode, attr, data, fops); } /** @@ -649,79 +476,50 @@ static struct dentry *eventfs_root_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { - const struct file_operations *fops; - const struct eventfs_entry *entry; struct eventfs_inode *ei_child; struct tracefs_inode *ti; struct eventfs_inode *ei; - struct dentry *ei_dentry = NULL; - struct dentry *ret = NULL; - struct dentry *d; const char *name = dentry->d_name.name; - umode_t mode; - void *data; - int idx; - int i; - int r; + struct dentry *result = NULL; ti = get_tracefs(dir); if (!(ti->flags & TRACEFS_EVENT_INODE)) - return NULL; - - /* Grab srcu to prevent the ei from going away */ - idx = srcu_read_lock(&eventfs_srcu); + return ERR_PTR(-EIO); - /* - * Grab the eventfs_mutex to consistent value from ti->private. - * This s - */ mutex_lock(&eventfs_mutex); - ei = READ_ONCE(ti->private); - if (ei && !ei->is_freed) - ei_dentry = READ_ONCE(ei->dentry); - mutex_unlock(&eventfs_mutex); - if (!ei || !ei_dentry) + ei = ti->private; + if (!ei || ei->is_freed) goto out; - data = ei->data; - - list_for_each_entry_srcu(ei_child, &ei->children, list, - srcu_read_lock_held(&eventfs_srcu)) { + list_for_each_entry(ei_child, &ei->children, list) { if (strcmp(ei_child->name, name) != 0) continue; - ret = simple_lookup(dir, dentry, flags); - if (IS_ERR(ret)) + if (ei_child->is_freed) goto out; - d = create_dir_dentry(ei, ei_child, ei_dentry); - dput(d); + result = lookup_dir_entry(dentry, ei, ei_child); goto out; } - for (i = 0; i < ei->nr_entries; i++) { - entry = &ei->entries[i]; - if (strcmp(name, entry->name) == 0) { - void *cdata = data; - mutex_lock(&eventfs_mutex); - /* If ei->is_freed, then the event itself may be too */ - if (!ei->is_freed) - r = entry->callback(name, &mode, &cdata, &fops); - else - r = -1; - mutex_unlock(&eventfs_mutex); - if (r <= 0) - continue; - ret = simple_lookup(dir, dentry, flags); - if (IS_ERR(ret)) - goto out; - d = create_file_dentry(ei, i, ei_dentry, name, mode, cdata, fops); - dput(d); - break; - } + for (int i = 0; i < ei->nr_entries; i++) { + void *data; + umode_t mode; + const struct file_operations *fops; + const struct eventfs_entry *entry = &ei->entries[i]; + + if (strcmp(name, entry->name) != 0) + continue; + + data = ei->data; + if (entry->callback(name, &mode, &data, &fops) <= 0) + goto out; + + result = lookup_file_dentry(dentry, ei, i, mode, data, fops); + goto out; } out: - srcu_read_unlock(&eventfs_srcu, idx); - return ret; + mutex_unlock(&eventfs_mutex); + return result; } /* @@ -871,25 +669,10 @@ struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode if (!parent) return ERR_PTR(-EINVAL); - ei = kzalloc(sizeof(*ei), GFP_KERNEL); + ei = alloc_ei(name); if (!ei) return ERR_PTR(-ENOMEM); - ei->name = kstrdup_const(name, GFP_KERNEL); - if (!ei->name) { - kfree(ei); - return ERR_PTR(-ENOMEM); - } - - if (size) { - ei->d_children = kcalloc(size, sizeof(*ei->d_children), GFP_KERNEL); - if (!ei->d_children) { - kfree_const(ei->name); - kfree(ei); - return ERR_PTR(-ENOMEM); - } - } - ei->entries = entries; ei->nr_entries = size; ei->data = data; @@ -897,10 +680,8 @@ struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode INIT_LIST_HEAD(&ei->list); mutex_lock(&eventfs_mutex); - if (!parent->is_freed) { + if (!parent->is_freed) list_add_tail(&ei->list, &parent->children); - ei->d_parent = parent->dentry; - } mutex_unlock(&eventfs_mutex); /* Was the parent freed? */ @@ -940,28 +721,20 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry if (IS_ERR(dentry)) return ERR_CAST(dentry); - ei = kzalloc(sizeof(*ei), GFP_KERNEL); + ei = alloc_ei(name); if (!ei) - goto fail_ei; + goto fail; inode = tracefs_get_inode(dentry->d_sb); if (unlikely(!inode)) goto fail; - if (size) { - ei->d_children = kcalloc(size, sizeof(*ei->d_children), GFP_KERNEL); - if (!ei->d_children) - goto fail; - } - - ei->dentry = dentry; + // Note: we have a ref to the dentry from tracefs_start_creating() + ei->events_dir = dentry; ei->entries = entries; ei->nr_entries = size; ei->is_events = 1; ei->data = data; - ei->name = kstrdup_const(name, GFP_KERNEL); - if (!ei->name) - goto fail; /* Save the ownership of this directory */ uid = d_inode(dentry->d_parent)->i_uid; @@ -992,11 +765,19 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry inode->i_op = &eventfs_root_dir_inode_operations; inode->i_fop = &eventfs_file_operations; - dentry->d_fsdata = ei; + dentry->d_fsdata = get_ei(ei); - /* directory inodes start off with i_nlink == 2 (for "." entry) */ - inc_nlink(inode); + /* + * Keep all eventfs directories with i_nlink == 1. + * Due to the dynamic nature of the dentry creations and not + * wanting to add a pointer to the parent eventfs_inode in the + * eventfs_inode structure, keeping the i_nlink in sync with the + * number of directories would cause too much complexity for + * something not worth much. Keeping directory links at 1 + * tells userspace not to trust the link number. + */ d_instantiate(dentry, inode); + /* The dentry of the "events" parent does keep track though */ inc_nlink(dentry->d_parent->d_inode); fsnotify_mkdir(dentry->d_parent->d_inode, dentry); tracefs_end_creating(dentry); @@ -1004,72 +785,11 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry return ei; fail: - kfree(ei->d_children); - kfree(ei); - fail_ei: + free_ei(ei); tracefs_failed_creating(dentry); return ERR_PTR(-ENOMEM); } -static LLIST_HEAD(free_list); - -static void eventfs_workfn(struct work_struct *work) -{ - struct eventfs_inode *ei, *tmp; - struct llist_node *llnode; - - llnode = llist_del_all(&free_list); - llist_for_each_entry_safe(ei, tmp, llnode, llist) { - /* This dput() matches the dget() from unhook_dentry() */ - for (int i = 0; i < ei->nr_entries; i++) { - if (ei->d_children[i]) - dput(ei->d_children[i]); - } - /* This should only get here if it had a dentry */ - if (!WARN_ON_ONCE(!ei->dentry)) - dput(ei->dentry); - } -} - -static DECLARE_WORK(eventfs_work, eventfs_workfn); - -static void free_rcu_ei(struct rcu_head *head) -{ - struct eventfs_inode *ei = container_of(head, struct eventfs_inode, rcu); - - if (ei->dentry) { - /* Do not free the ei until all references of dentry are gone */ - if (llist_add(&ei->llist, &free_list)) - queue_work(system_unbound_wq, &eventfs_work); - return; - } - - /* If the ei doesn't have a dentry, neither should its children */ - for (int i = 0; i < ei->nr_entries; i++) { - WARN_ON_ONCE(ei->d_children[i]); - } - - free_ei(ei); -} - -static void unhook_dentry(struct dentry *dentry) -{ - if (!dentry) - return; - /* - * Need to add a reference to the dentry that is expected by - * simple_recursive_removal(), which will include a dput(). - */ - dget(dentry); - - /* - * Also add a reference for the dput() in eventfs_workfn(). - * That is required as that dput() will free the ei after - * the SRCU grace period is over. - */ - dget(dentry); -} - /** * eventfs_remove_rec - remove eventfs dir or file from list * @ei: eventfs_inode to be removed. @@ -1082,8 +802,6 @@ static void eventfs_remove_rec(struct eventfs_inode *ei, int level) { struct eventfs_inode *ei_child; - if (!ei) - return; /* * Check recursion depth. It should never be greater than 3: * 0 - events/ @@ -1095,28 +813,11 @@ static void eventfs_remove_rec(struct eventfs_inode *ei, int level) return; /* search for nested folders or files */ - list_for_each_entry_srcu(ei_child, &ei->children, list, - lockdep_is_held(&eventfs_mutex)) { - /* Children only have dentry if parent does */ - WARN_ON_ONCE(ei_child->dentry && !ei->dentry); + list_for_each_entry(ei_child, &ei->children, list) eventfs_remove_rec(ei_child, level + 1); - } - - - ei->is_freed = 1; - for (int i = 0; i < ei->nr_entries; i++) { - if (ei->d_children[i]) { - /* Children only have dentry if parent does */ - WARN_ON_ONCE(!ei->dentry); - unhook_dentry(ei->d_children[i]); - } - } - - unhook_dentry(ei->dentry); - - list_del_rcu(&ei->list); - call_srcu(&eventfs_srcu, &ei->rcu, free_rcu_ei); + list_del(&ei->list); + free_ei(ei); } /** @@ -1127,22 +828,12 @@ static void eventfs_remove_rec(struct eventfs_inode *ei, int level) */ void eventfs_remove_dir(struct eventfs_inode *ei) { - struct dentry *dentry; - if (!ei) return; mutex_lock(&eventfs_mutex); - dentry = ei->dentry; eventfs_remove_rec(ei, 0); mutex_unlock(&eventfs_mutex); - - /* - * If any of the ei children has a dentry, then the ei itself - * must have a dentry. - */ - if (dentry) - simple_recursive_removal(dentry, NULL); } /** @@ -1155,7 +846,11 @@ void eventfs_remove_events_dir(struct eventfs_inode *ei) { struct dentry *dentry; - dentry = ei->dentry; + dentry = ei->events_dir; + if (!dentry) + return; + + ei->events_dir = NULL; eventfs_remove_dir(ei); /* @@ -1165,5 +860,6 @@ void eventfs_remove_events_dir(struct eventfs_inode *ei) * sticks around while the other ei->dentry are created * and destroyed dynamically. */ + d_invalidate(dentry); dput(dentry); } diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c index e1b172c0e091..d65ffad4c327 100644 --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -38,8 +38,6 @@ static struct inode *tracefs_alloc_inode(struct super_block *sb) if (!ti) return NULL; - ti->flags = 0; - return &ti->vfs_inode; } @@ -379,21 +377,30 @@ static const struct super_operations tracefs_super_operations = { .show_options = tracefs_show_options, }; -static void tracefs_dentry_iput(struct dentry *dentry, struct inode *inode) +/* + * It would be cleaner if eventfs had its own dentry ops. + * + * Note that d_revalidate is called potentially under RCU, + * so it can't take the eventfs mutex etc. It's fine - if + * we open a file just as it's marked dead, things will + * still work just fine, and just see the old stale case. + */ +static void tracefs_d_release(struct dentry *dentry) { - struct tracefs_inode *ti; + if (dentry->d_fsdata) + eventfs_d_release(dentry); +} - if (!dentry || !inode) - return; +static int tracefs_d_revalidate(struct dentry *dentry, unsigned int flags) +{ + struct eventfs_inode *ei = dentry->d_fsdata; - ti = get_tracefs(inode); - if (ti && ti->flags & TRACEFS_EVENT_INODE) - eventfs_set_ei_status_free(ti, dentry); - iput(inode); + return !(ei && ei->is_freed); } static const struct dentry_operations tracefs_dentry_operations = { - .d_iput = tracefs_dentry_iput, + .d_revalidate = tracefs_d_revalidate, + .d_release = tracefs_d_release, }; static int trace_fill_super(struct super_block *sb, void *data, int silent) @@ -497,75 +504,6 @@ struct dentry *tracefs_end_creating(struct dentry *dentry) return dentry; } -/** - * eventfs_start_creating - start the process of creating a dentry - * @name: Name of the file created for the dentry - * @parent: The parent dentry where this dentry will be created - * - * This is a simple helper function for the dynamically created eventfs - * files. When the directory of the eventfs files are accessed, their - * dentries are created on the fly. This function is used to start that - * process. - */ -struct dentry *eventfs_start_creating(const char *name, struct dentry *parent) -{ - struct dentry *dentry; - int error; - - /* Must always have a parent. */ - if (WARN_ON_ONCE(!parent)) - return ERR_PTR(-EINVAL); - - error = simple_pin_fs(&trace_fs_type, &tracefs_mount, - &tracefs_mount_count); - if (error) - return ERR_PTR(error); - - if (unlikely(IS_DEADDIR(parent->d_inode))) - dentry = ERR_PTR(-ENOENT); - else - dentry = lookup_one_len(name, parent, strlen(name)); - - if (!IS_ERR(dentry) && dentry->d_inode) { - dput(dentry); - dentry = ERR_PTR(-EEXIST); - } - - if (IS_ERR(dentry)) - simple_release_fs(&tracefs_mount, &tracefs_mount_count); - - return dentry; -} - -/** - * eventfs_failed_creating - clean up a failed eventfs dentry creation - * @dentry: The dentry to clean up - * - * If after calling eventfs_start_creating(), a failure is detected, the - * resources created by eventfs_start_creating() needs to be cleaned up. In - * that case, this function should be called to perform that clean up. - */ -struct dentry *eventfs_failed_creating(struct dentry *dentry) -{ - dput(dentry); - simple_release_fs(&tracefs_mount, &tracefs_mount_count); - return NULL; -} - -/** - * eventfs_end_creating - Finish the process of creating a eventfs dentry - * @dentry: The dentry that has successfully been created. - * - * This function is currently just a place holder to match - * eventfs_start_creating(). In case any synchronization needs to be added, - * this function will be used to implement that without having to modify - * the callers of eventfs_start_creating(). - */ -struct dentry *eventfs_end_creating(struct dentry *dentry) -{ - return dentry; -} - /* Find the inode that this will use for default */ static struct inode *instance_inode(struct dentry *parent, struct inode *inode) { @@ -779,7 +717,11 @@ static void init_once(void *foo) { struct tracefs_inode *ti = (struct tracefs_inode *) foo; + /* inode_init_once() calls memset() on the vfs_inode portion */ inode_init_once(&ti->vfs_inode); + + /* Zero out the rest */ + memset_after(ti, 0, vfs_inode); } static int __init tracefs_init(void) diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h index 45397df9bb65..beb3dcd0e434 100644 --- a/fs/tracefs/internal.h +++ b/fs/tracefs/internal.h @@ -11,9 +11,10 @@ enum { }; struct tracefs_inode { + struct inode vfs_inode; + /* The below gets initialized with memset_after(ti, 0, vfs_inode) */ unsigned long flags; void *private; - struct inode vfs_inode; }; /* @@ -31,43 +32,37 @@ struct eventfs_attr { /* * struct eventfs_inode - hold the properties of the eventfs directories. * @list: link list into the parent directory + * @rcu: Union with @list for freeing + * @children: link list into the child eventfs_inode * @entries: the array of entries representing the files in the directory * @name: the name of the directory to create - * @children: link list into the child eventfs_inode - * @dentry: the dentry of the directory - * @d_parent: pointer to the parent's dentry - * @d_children: The array of dentries to represent the files when created + * @events_dir: the dentry of the events directory * @entry_attrs: Saved mode and ownership of the @d_children - * @attr: Saved mode and ownership of eventfs_inode itself * @data: The private data to pass to the callbacks + * @attr: Saved mode and ownership of eventfs_inode itself * @is_freed: Flag set if the eventfs is on its way to be freed * Note if is_freed is set, then dentry is corrupted. + * @is_events: Flag set for only the top level "events" directory * @nr_entries: The number of items in @entries + * @ino: The saved inode number */ struct eventfs_inode { - struct list_head list; + union { + struct list_head list; + struct rcu_head rcu; + }; + struct list_head children; const struct eventfs_entry *entries; const char *name; - struct list_head children; - struct dentry *dentry; /* Check is_freed to access */ - struct dentry *d_parent; - struct dentry **d_children; + struct dentry *events_dir; struct eventfs_attr *entry_attrs; - struct eventfs_attr attr; void *data; + struct eventfs_attr attr; + struct kref kref; unsigned int is_freed:1; unsigned int is_events:1; unsigned int nr_entries:30; unsigned int ino; - /* - * Union - used for deletion - * @llist: for calling dput() if needed after RCU - * @rcu: eventfs_inode to delete in RCU - */ - union { - struct llist_node llist; - struct rcu_head rcu; - }; }; static inline struct tracefs_inode *get_tracefs(const struct inode *inode) @@ -79,10 +74,7 @@ struct dentry *tracefs_start_creating(const char *name, struct dentry *parent); struct dentry *tracefs_end_creating(struct dentry *dentry); struct dentry *tracefs_failed_creating(struct dentry *dentry); struct inode *tracefs_get_inode(struct super_block *sb); -struct dentry *eventfs_start_creating(const char *name, struct dentry *parent); -struct dentry *eventfs_failed_creating(struct dentry *dentry); -struct dentry *eventfs_end_creating(struct dentry *dentry); -void eventfs_update_gid(struct dentry *dentry, kgid_t gid); -void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry); + +void eventfs_d_release(struct dentry *dentry); #endif /* _TRACEFS_INTERNAL_H */ |