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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [fs/] [iobuf.c] - Rev 1774
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/* * iobuf.c * * Keep track of the general-purpose IO-buffer structures used to track * abstract kernel-space io buffers. * */ #include <linux/iobuf.h> #include <linux/slab.h> #include <linux/vmalloc.h> static kmem_cache_t *kiobuf_cachep; void end_kio_request(struct kiobuf *kiobuf, int uptodate) { if ((!uptodate) && !kiobuf->errno) kiobuf->errno = -EIO; if (atomic_dec_and_test(&kiobuf->io_count)) { if (kiobuf->end_io) kiobuf->end_io(kiobuf); wake_up(&kiobuf->wait_queue); } } static int kiobuf_init(struct kiobuf *iobuf) { init_waitqueue_head(&iobuf->wait_queue); iobuf->array_len = 0; iobuf->nr_pages = 0; iobuf->locked = 0; iobuf->bh = NULL; iobuf->blocks = NULL; atomic_set(&iobuf->io_count, 0); iobuf->end_io = NULL; return expand_kiobuf(iobuf, KIO_STATIC_PAGES); } int alloc_kiobuf_bhs(struct kiobuf * kiobuf) { int i; kiobuf->blocks = kmalloc(sizeof(*kiobuf->blocks) * KIO_MAX_SECTORS, GFP_KERNEL); if (unlikely(!kiobuf->blocks)) goto nomem; kiobuf->bh = kmalloc(sizeof(*kiobuf->bh) * KIO_MAX_SECTORS, GFP_KERNEL); if (unlikely(!kiobuf->bh)) goto nomem; for (i = 0; i < KIO_MAX_SECTORS; i++) { kiobuf->bh[i] = kmem_cache_alloc(bh_cachep, GFP_KERNEL); if (unlikely(!kiobuf->bh[i])) goto nomem2; } return 0; nomem2: while (i--) { kmem_cache_free(bh_cachep, kiobuf->bh[i]); kiobuf->bh[i] = NULL; } memset(kiobuf->bh, 0, sizeof(*kiobuf->bh) * KIO_MAX_SECTORS); nomem: free_kiobuf_bhs(kiobuf); return -ENOMEM; } void free_kiobuf_bhs(struct kiobuf * kiobuf) { int i; if (kiobuf->bh) { for (i = 0; i < KIO_MAX_SECTORS; i++) if (kiobuf->bh[i]) kmem_cache_free(bh_cachep, kiobuf->bh[i]); kfree(kiobuf->bh); kiobuf->bh = NULL; } if (kiobuf->blocks) { kfree(kiobuf->blocks); kiobuf->blocks = NULL; } } int alloc_kiovec(int nr, struct kiobuf **bufp) { int i; struct kiobuf *iobuf; for (i = 0; i < nr; i++) { iobuf = kmem_cache_alloc(kiobuf_cachep, GFP_KERNEL); if (unlikely(!iobuf)) goto nomem; if (unlikely(kiobuf_init(iobuf))) goto nomem2; if (unlikely(alloc_kiobuf_bhs(iobuf))) goto nomem2; bufp[i] = iobuf; } return 0; nomem2: kmem_cache_free(kiobuf_cachep, iobuf); nomem: free_kiovec(i, bufp); return -ENOMEM; } void free_kiovec(int nr, struct kiobuf **bufp) { int i; struct kiobuf *iobuf; for (i = 0; i < nr; i++) { iobuf = bufp[i]; if (iobuf->locked) unlock_kiovec(1, &iobuf); kfree(iobuf->maplist); free_kiobuf_bhs(iobuf); kmem_cache_free(kiobuf_cachep, bufp[i]); } } int expand_kiobuf(struct kiobuf *iobuf, int wanted) { struct page ** maplist; if (iobuf->array_len >= wanted) return 0; maplist = kmalloc(wanted * sizeof(struct page **), GFP_KERNEL); if (unlikely(!maplist)) return -ENOMEM; /* Did it grow while we waited? */ if (unlikely(iobuf->array_len >= wanted)) { kfree(maplist); return 0; } if (iobuf->array_len) { memcpy(maplist, iobuf->maplist, iobuf->array_len * sizeof(*maplist)); kfree(iobuf->maplist); } iobuf->maplist = maplist; iobuf->array_len = wanted; return 0; } void kiobuf_wait_for_io(struct kiobuf *kiobuf) { struct task_struct *tsk = current; DECLARE_WAITQUEUE(wait, tsk); if (atomic_read(&kiobuf->io_count) == 0) return; add_wait_queue(&kiobuf->wait_queue, &wait); repeat: set_task_state(tsk, TASK_UNINTERRUPTIBLE); if (atomic_read(&kiobuf->io_count) != 0) { run_task_queue(&tq_disk); schedule(); if (atomic_read(&kiobuf->io_count) != 0) goto repeat; } tsk->state = TASK_RUNNING; remove_wait_queue(&kiobuf->wait_queue, &wait); } void __init iobuf_cache_init(void) { kiobuf_cachep = kmem_cache_create("kiobuf", sizeof(struct kiobuf), 0, SLAB_HWCACHE_ALIGN, NULL, NULL); if (!kiobuf_cachep) panic("Cannot create kiobuf SLAB cache"); }
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