From 39ce81ce7168aa7226fb9f182c3a2b57060d0905 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Tue, 18 Nov 2008 18:09:49 +0200 Subject: UBIFS: do not print scary memory allocation warnings Bulk-read allocates a lot of memory with 'kmalloc()', and when it is/gets fragmented 'kmalloc()' fails with a scarry warning. But because bulk-read is just an optimization, UBIFS keeps working fine. Supress the warning by passing __GFP_NOWARN option to 'kmalloc()'. This patch also introduces a macro for the magic 128KiB constant. This is just neater. Note, this is not really fixes the problem we had, but just hides the warnings. The further patches fix the problem. Signed-off-by: Artem Bityutskiy --- fs/ubifs/super.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'fs/ubifs/super.c') diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index 8780efbf40ac..ea493e6f2652 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -36,6 +36,12 @@ #include #include "ubifs.h" +/* + * Maximum amount of memory we may 'kmalloc()' without worrying that we are + * allocating too much. + */ +#define UBIFS_KMALLOC_OK (128*1024) + /* Slab cache for UBIFS inodes */ struct kmem_cache *ubifs_inode_slab; @@ -561,17 +567,18 @@ static int init_constants_early(struct ubifs_info *c) * calculations when reporting free space. */ 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 > 128 * 1024) { - /* Check if we can kmalloc more than 128KiB */ - void *try = kmalloc(c->bulk_read_buf_size, GFP_KERNEL); - + if (c->bulk_read_buf_size > UBIFS_KMALLOC_OK) { + /* Check if we can kmalloc that much */ + void *try = kmalloc(c->bulk_read_buf_size, + GFP_KERNEL | __GFP_NOWARN); kfree(try); if (!try) - c->bulk_read_buf_size = 128 * 1024; + c->bulk_read_buf_size = UBIFS_KMALLOC_OK; } return 0; } -- cgit v1.2.1 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/super.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'fs/ubifs/super.c') diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index ea493e6f2652..1d511569c035 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; } -- cgit v1.2.1 From 3477d204658733aa3a87d3ae03b0327c1e599517 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Wed, 19 Nov 2008 11:53:15 +0200 Subject: UBIFS: pre-allocate bulk-read buffer To avoid memory allocation failure during bulk-read, pre-allocate a bulk-read buffer, so that if there is only one bulk-reader at a time, it would just use the pre-allocated buffer and would not do any memory allocation. However, if there are more than 1 bulk- reader, then only one reader would use the pre-allocated buffer, while the other reader would allocate the buffer for itself. Signed-off-by: Artem Bityutskiy --- fs/ubifs/super.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 48 insertions(+), 9 deletions(-) (limited to 'fs/ubifs/super.c') diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index 1d511569c035..d80b2aef42b6 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -572,14 +572,6 @@ static int init_constants_early(struct ubifs_info *c) 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->max_bu_buf_len, - GFP_KERNEL | __GFP_NOWARN); - kfree(try); - if (!try) - c->max_bu_buf_len = UBIFS_KMALLOC_OK; - } return 0; } @@ -998,6 +990,34 @@ static void destroy_journal(struct ubifs_info *c) free_buds(c); } +/** + * bu_init - initialize bulk-read information. + * @c: UBIFS file-system description object + */ +static void bu_init(struct ubifs_info *c) +{ + ubifs_assert(c->bulk_read == 1); + + if (c->bu.buf) + return; /* Already initialized */ + +again: + c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN); + if (!c->bu.buf) { + if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) { + c->max_bu_buf_len = UBIFS_KMALLOC_OK; + goto again; + } + + /* Just disable bulk-read */ + ubifs_warn("Cannot allocate %d bytes of memory for bulk-read, " + "disabling it", c->max_bu_buf_len); + c->mount_opts.bulk_read = 1; + c->bulk_read = 0; + return; + } +} + /** * mount_ubifs - mount UBIFS file-system. * @c: UBIFS file-system description object @@ -1066,6 +1086,13 @@ static int mount_ubifs(struct ubifs_info *c) goto out_free; } + if (c->bulk_read == 1) + bu_init(c); + + /* + * We have to check all CRCs, even for data nodes, when we mount the FS + * (specifically, when we are replaying). + */ c->always_chk_crc = 1; err = ubifs_read_superblock(c); @@ -1296,6 +1323,7 @@ out_cbuf: out_dereg: dbg_failure_mode_deregistration(c); out_free: + kfree(c->bu.buf); vfree(c->ileb_buf); vfree(c->sbuf); kfree(c->bottom_up_buf); @@ -1332,10 +1360,11 @@ static void ubifs_umount(struct ubifs_info *c) kfree(c->cbuf); kfree(c->rcvrd_mst_node); kfree(c->mst_node); + kfree(c->bu.buf); + vfree(c->ileb_buf); vfree(c->sbuf); kfree(c->bottom_up_buf); UBIFS_DBG(vfree(c->dbg_buf)); - vfree(c->ileb_buf); dbg_failure_mode_deregistration(c); } @@ -1633,6 +1662,7 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data) ubifs_err("invalid or unknown remount parameter"); return err; } + if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) { err = ubifs_remount_rw(c); if (err) @@ -1640,6 +1670,14 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data) } else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY)) ubifs_remount_ro(c); + if (c->bulk_read == 1) + bu_init(c); + else { + dbg_gen("disable bulk-read"); + kfree(c->bu.buf); + c->bu.buf = NULL; + } + return 0; } @@ -1730,6 +1768,7 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent) mutex_init(&c->log_mutex); mutex_init(&c->mst_mutex); mutex_init(&c->umount_mutex); + mutex_init(&c->bu_mutex); init_waitqueue_head(&c->cmt_wq); c->buds = RB_ROOT; c->old_idx = RB_ROOT; -- cgit v1.2.1