diff options
| -rw-r--r-- | fs/ubifs/journal.c | 28 | ||||
| -rw-r--r-- | fs/ubifs/super.c | 18 | ||||
| -rw-r--r-- | fs/ubifs/ubifs.h | 14 |
3 files changed, 54 insertions, 6 deletions
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index 914f1bd89e5..aed25e86422 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -690,7 +690,7 @@ int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode, { struct ubifs_data_node *data; int err, lnum, offs, compr_type, out_len; - int dlen = UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE * WORST_COMPR_FACTOR; + int dlen = COMPRESSED_DATA_NODE_BUF_SZ, allocated = 1; struct ubifs_inode *ui = ubifs_inode(inode); dbg_jnl("ino %lu, blk %u, len %d, key %s", @@ -698,9 +698,19 @@ int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode, DBGKEY(key)); ubifs_assert(len <= UBIFS_BLOCK_SIZE); - data = kmalloc(dlen, GFP_NOFS); - if (!data) - return -ENOMEM; + data = kmalloc(dlen, GFP_NOFS | __GFP_NOWARN); + if (!data) { + /* + * Fall-back to the write reserve buffer. Note, we might be + * currently on the memory reclaim path, when the kernel is + * trying to free some memory by writing out dirty pages. The + * write reserve buffer helps us to guarantee that we are + * always able to write the data. + */ + allocated = 0; + mutex_lock(&c->write_reserve_mutex); + data = c->write_reserve_buf; + } data->ch.node_type = UBIFS_DATA_NODE; key_write(c, key, &data->key); @@ -736,7 +746,10 @@ int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode, goto out_ro; finish_reservation(c); - kfree(data); + if (!allocated) + mutex_unlock(&c->write_reserve_mutex); + else + kfree(data); return 0; out_release: @@ -745,7 +758,10 @@ out_ro: ubifs_ro_mode(c, err); finish_reservation(c); out_free: - kfree(data); + if (!allocated) + mutex_unlock(&c->write_reserve_mutex); + else + kfree(data); return err; } diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index d4b4cb4596e..e360c7a71f9 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -1213,6 +1213,13 @@ static int mount_ubifs(struct ubifs_info *c) if (c->bulk_read == 1) bu_init(c); + if (!c->ro_mount) { + c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, + GFP_KERNEL); + if (!c->write_reserve_buf) + goto out_free; + } + c->mounting = 1; err = ubifs_read_superblock(c); @@ -1482,6 +1489,7 @@ out_wbufs: out_cbuf: kfree(c->cbuf); out_free: + kfree(c->write_reserve_buf); kfree(c->bu.buf); vfree(c->ileb_buf); vfree(c->sbuf); @@ -1520,6 +1528,7 @@ static void ubifs_umount(struct ubifs_info *c) kfree(c->cbuf); kfree(c->rcvrd_mst_node); kfree(c->mst_node); + kfree(c->write_reserve_buf); kfree(c->bu.buf); vfree(c->ileb_buf); vfree(c->sbuf); @@ -1605,6 +1614,10 @@ static int ubifs_remount_rw(struct ubifs_info *c) goto out; } + c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, GFP_KERNEL); + if (!c->write_reserve_buf) + goto out; + err = ubifs_lpt_init(c, 0, 1); if (err) goto out; @@ -1669,6 +1682,8 @@ out: c->bgt = NULL; } free_wbufs(c); + kfree(c->write_reserve_buf); + c->write_reserve_buf = NULL; vfree(c->ileb_buf); c->ileb_buf = NULL; ubifs_lpt_free(c, 1); @@ -1712,6 +1727,8 @@ static void ubifs_remount_ro(struct ubifs_info *c) free_wbufs(c); vfree(c->orph_buf); c->orph_buf = NULL; + kfree(c->write_reserve_buf); + c->write_reserve_buf = NULL; vfree(c->ileb_buf); c->ileb_buf = NULL; ubifs_lpt_free(c, 1); @@ -1942,6 +1959,7 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent) mutex_init(&c->mst_mutex); mutex_init(&c->umount_mutex); mutex_init(&c->bu_mutex); + mutex_init(&c->write_reserve_mutex); init_waitqueue_head(&c->cmt_wq); c->buds = RB_ROOT; c->old_idx = RB_ROOT; diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index 36249507848..8c40ad3c672 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -151,6 +151,12 @@ */ #define WORST_COMPR_FACTOR 2 +/* + * How much memory is needed for a buffer where we comress a data node. + */ +#define COMPRESSED_DATA_NODE_BUF_SZ \ + (UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE * WORST_COMPR_FACTOR) + /* Maximum expected tree height for use by bottom_up_buf */ #define BOTTOM_UP_HEIGHT 64 @@ -1005,6 +1011,11 @@ struct ubifs_debug_info; * @bu_mutex: protects the pre-allocated bulk-read buffer and @c->bu * @bu: pre-allocated bulk-read information * + * @write_reserve_mutex: protects @write_reserve_buf + * @write_reserve_buf: on the write path we allocate memory, which might + * sometimes be unavailable, in which case we use this + * write reserve buffer + * * @log_lebs: number of logical eraseblocks in the log * @log_bytes: log size in bytes * @log_last: last LEB of the log @@ -1256,6 +1267,9 @@ struct ubifs_info { struct mutex bu_mutex; struct bu_info bu; + struct mutex write_reserve_mutex; + void *write_reserve_buf; + int log_lebs; long long log_bytes; int log_last; |