From 6c0c42cdfd73fb161417403d8d077cb136e10bbf Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Tue, 18 Nov 2008 20:20:05 +0200 Subject: UBIFS: do not allocate too much Bulk-read allocates 128KiB or more using kmalloc. The allocation starts failing often when the memory gets fragmented. UBIFS still works fine in this case, because it falls-back to standard (non-optimized) read method, though. This patch teaches bulk-read to allocate exactly the amount of memory it needs, instead of allocating 128KiB every time. This patch is also a preparation to the further fix where we'll have a pre-allocated bulk-read buffer as well. For example, now the @bu object is prepared in 'ubifs_bulk_read()', so we could path either pre-allocated or allocated information to 'ubifs_do_bulk_read()' later. Or teaching 'ubifs_do_bulk_read()' not to allocate 'bu->buf' if it is already there. Signed-off-by: Artem Bityutskiy --- fs/ubifs/file.c | 70 +++++++++++++++++++++++++++++++++++++------------------- fs/ubifs/super.c | 12 +++++----- fs/ubifs/tnc.c | 7 +++++- fs/ubifs/ubifs.h | 4 ++-- 4 files changed, 60 insertions(+), 33 deletions(-) (limited to 'fs') diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c index 8be827cc707..0c5c27d63f6 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -691,32 +691,22 @@ out_err: /** * ubifs_do_bulk_read - do bulk-read. * @c: UBIFS file-system description object - * @page1: first page + * @bu: bulk-read information + * @page1: first page to read * * This function returns %1 if the bulk-read is done, otherwise %0 is returned. */ -static int ubifs_do_bulk_read(struct ubifs_info *c, struct page *page1) +static int ubifs_do_bulk_read(struct ubifs_info *c, struct bu_info *bu, + struct page *page1) { pgoff_t offset = page1->index, end_index; struct address_space *mapping = page1->mapping; struct inode *inode = mapping->host; struct ubifs_inode *ui = ubifs_inode(inode); - struct bu_info *bu; int err, page_idx, page_cnt, ret = 0, n = 0; + int allocate = bu->buf ? 0 : 1; loff_t isize; - bu = kmalloc(sizeof(struct bu_info), GFP_NOFS | __GFP_NOWARN); - if (!bu) - return 0; - - bu->buf_len = c->bulk_read_buf_size; - bu->buf = kmalloc(bu->buf_len, GFP_NOFS | __GFP_NOWARN); - if (!bu->buf) - goto out_free; - - data_key_init(c, &bu->key, inode->i_ino, - offset << UBIFS_BLOCKS_PER_PAGE_SHIFT); - err = ubifs_tnc_get_bu_keys(c, bu); if (err) goto out_warn; @@ -735,12 +725,25 @@ static int ubifs_do_bulk_read(struct ubifs_info *c, struct page *page1) * together. If all the pages were like this, bulk-read would * reduce performance, so we turn it off for a while. */ - ui->read_in_a_row = 0; - ui->bulk_read = 0; - goto out_free; + goto out_bu_off; } if (bu->cnt) { + if (allocate) { + /* + * Allocate bulk-read buffer depending on how many data + * nodes we are going to read. + */ + bu->buf_len = bu->zbranch[bu->cnt - 1].offs + + bu->zbranch[bu->cnt - 1].len - + bu->zbranch[0].offs; + ubifs_assert(bu->buf_len > 0); + ubifs_assert(bu->buf_len <= c->leb_size); + bu->buf = kmalloc(bu->buf_len, GFP_NOFS | __GFP_NOWARN); + if (!bu->buf) + goto out_bu_off; + } + err = ubifs_tnc_bulk_read(c, bu); if (err) goto out_warn; @@ -779,13 +782,17 @@ static int ubifs_do_bulk_read(struct ubifs_info *c, struct page *page1) ui->last_page_read = offset + page_idx - 1; out_free: - kfree(bu->buf); - kfree(bu); + if (allocate) + kfree(bu->buf); return ret; out_warn: ubifs_warn("ignoring error %d and skipping bulk-read", err); goto out_free; + +out_bu_off: + ui->read_in_a_row = ui->bulk_read = 0; + goto out_free; } /** @@ -803,18 +810,20 @@ static int ubifs_bulk_read(struct page *page) struct ubifs_info *c = inode->i_sb->s_fs_info; struct ubifs_inode *ui = ubifs_inode(inode); pgoff_t index = page->index, last_page_read = ui->last_page_read; - int ret = 0; + struct bu_info *bu; + int err = 0; ui->last_page_read = index; - if (!c->bulk_read) return 0; + /* * Bulk-read is protected by ui_mutex, but it is an optimization, so * don't bother if we cannot lock the mutex. */ if (!mutex_trylock(&ui->ui_mutex)) return 0; + if (index != last_page_read + 1) { /* Turn off bulk-read if we stop reading sequentially */ ui->read_in_a_row = 1; @@ -822,6 +831,7 @@ static int ubifs_bulk_read(struct page *page) ui->bulk_read = 0; goto out_unlock; } + if (!ui->bulk_read) { ui->read_in_a_row += 1; if (ui->read_in_a_row < 3) @@ -829,10 +839,22 @@ static int ubifs_bulk_read(struct page *page) /* Three reads in a row, so switch on bulk-read */ ui->bulk_read = 1; } - ret = ubifs_do_bulk_read(c, page); + + bu = kmalloc(sizeof(struct bu_info), GFP_NOFS | __GFP_NOWARN); + if (!bu) + return 0; + + bu->buf = NULL; + bu->buf_len = c->max_bu_buf_len; + data_key_init(c, &bu->key, inode->i_ino, + page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT); + + err = ubifs_do_bulk_read(c, bu, page); + kfree(bu); + out_unlock: mutex_unlock(&ui->ui_mutex); - return ret; + return err; } static int ubifs_readpage(struct file *file, struct page *page) diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index ea493e6f265..1d511569c03 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -569,16 +569,16 @@ static int init_constants_early(struct ubifs_info *c) c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ; /* Buffer size for bulk-reads */ - c->bulk_read_buf_size = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ; - if (c->bulk_read_buf_size > c->leb_size) - c->bulk_read_buf_size = c->leb_size; - if (c->bulk_read_buf_size > UBIFS_KMALLOC_OK) { + c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ; + if (c->max_bu_buf_len > c->leb_size) + c->max_bu_buf_len = c->leb_size; + if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) { /* Check if we can kmalloc that much */ - void *try = kmalloc(c->bulk_read_buf_size, + void *try = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN); kfree(try); if (!try) - c->bulk_read_buf_size = UBIFS_KMALLOC_OK; + c->max_bu_buf_len = UBIFS_KMALLOC_OK; } return 0; } diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c index 99e9a744cfd..6eef5344a14 100644 --- a/fs/ubifs/tnc.c +++ b/fs/ubifs/tnc.c @@ -1501,7 +1501,12 @@ out: * @bu: bulk-read parameters and results * * Lookup consecutive data node keys for the same inode that reside - * consecutively in the same LEB. + * consecutively in the same LEB. This function returns zero in case of success + * and a negative error code in case of failure. + * + * Note, if the bulk-read buffer length (@bu->buf_len) is known, this function + * makes sure bulk-read nodes fit the buffer. Otherwise, this function prepares + * maxumum possible amount of nodes for bulk-read. */ int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu) { diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index 06ba51efd65..870b5c479e9 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -969,7 +969,7 @@ struct ubifs_mount_opts { * @mst_node: master node * @mst_offs: offset of valid master node * @mst_mutex: protects the master node area, @mst_node, and @mst_offs - * @bulk_read_buf_size: buffer size for bulk-reads + * @max_bu_buf_len: maximum bulk-read buffer length * * @log_lebs: number of logical eraseblocks in the log * @log_bytes: log size in bytes @@ -1217,7 +1217,7 @@ struct ubifs_info { struct ubifs_mst_node *mst_node; int mst_offs; struct mutex mst_mutex; - int bulk_read_buf_size; + int max_bu_buf_len; int log_lebs; long long log_bytes; -- cgit v1.2.3