/* AFS caching stuff
*
- * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* 2 of the License, or (at your option) any later version.
*/
-#ifdef AFS_CACHING_SUPPORT
-static cachefs_match_val_t afs_cell_cache_match(void *target,
- const void *entry);
-static void afs_cell_cache_update(void *source, void *entry);
-
-struct cachefs_index_def afs_cache_cell_index_def = {
- .name = "cell_ix",
- .data_size = sizeof(struct afs_cache_cell),
- .keys[0] = { CACHEFS_INDEX_KEYS_ASCIIZ, 64 },
- .match = afs_cell_cache_match,
- .update = afs_cell_cache_update,
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include "internal.h"
+
+static uint16_t afs_cell_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+static uint16_t afs_cell_cache_get_aux(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+static enum fscache_checkaux afs_cell_cache_check_aux(void *cookie_netfs_data,
+ const void *buffer,
+ uint16_t buflen);
+
+static uint16_t afs_vlocation_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+static uint16_t afs_vlocation_cache_get_aux(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+static enum fscache_checkaux afs_vlocation_cache_check_aux(
+ void *cookie_netfs_data, const void *buffer, uint16_t buflen);
+
+static uint16_t afs_volume_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+
+static uint16_t afs_vnode_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+static void afs_vnode_cache_get_attr(const void *cookie_netfs_data,
+ uint64_t *size);
+static uint16_t afs_vnode_cache_get_aux(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+static enum fscache_checkaux afs_vnode_cache_check_aux(void *cookie_netfs_data,
+ const void *buffer,
+ uint16_t buflen);
+static void afs_vnode_cache_now_uncached(void *cookie_netfs_data);
+
+struct fscache_netfs afs_cache_netfs = {
+ .name = "afs",
+ .version = 0,
+};
+
+struct fscache_cookie_def afs_cell_cache_index_def = {
+ .name = "AFS.cell",
+ .type = FSCACHE_COOKIE_TYPE_INDEX,
+ .get_key = afs_cell_cache_get_key,
+ .get_aux = afs_cell_cache_get_aux,
+ .check_aux = afs_cell_cache_check_aux,
+};
+
+struct fscache_cookie_def afs_vlocation_cache_index_def = {
+ .name = "AFS.vldb",
+ .type = FSCACHE_COOKIE_TYPE_INDEX,
+ .get_key = afs_vlocation_cache_get_key,
+ .get_aux = afs_vlocation_cache_get_aux,
+ .check_aux = afs_vlocation_cache_check_aux,
+};
+
+struct fscache_cookie_def afs_volume_cache_index_def = {
+ .name = "AFS.volume",
+ .type = FSCACHE_COOKIE_TYPE_INDEX,
+ .get_key = afs_volume_cache_get_key,
+};
+
+struct fscache_cookie_def afs_vnode_cache_index_def = {
+ .name = "AFS.vnode",
+ .type = FSCACHE_COOKIE_TYPE_DATAFILE,
+ .get_key = afs_vnode_cache_get_key,
+ .get_attr = afs_vnode_cache_get_attr,
+ .get_aux = afs_vnode_cache_get_aux,
+ .check_aux = afs_vnode_cache_check_aux,
+ .now_uncached = afs_vnode_cache_now_uncached,
};
-#endif
/*
- * match a cell record obtained from the cache
+ * set the key for the index entry
*/
-#ifdef AFS_CACHING_SUPPORT
-static cachefs_match_val_t afs_cell_cache_match(void *target,
- const void *entry)
+static uint16_t afs_cell_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
{
- const struct afs_cache_cell *ccell = entry;
- struct afs_cell *cell = target;
+ const struct afs_cell *cell = cookie_netfs_data;
+ uint16_t klen;
- _enter("{%s},{%s}", ccell->name, cell->name);
+ _enter("%p,%p,%u", cell, buffer, bufmax);
- if (strncmp(ccell->name, cell->name, sizeof(ccell->name)) == 0) {
- _leave(" = SUCCESS");
- return CACHEFS_MATCH_SUCCESS;
- }
+ klen = strlen(cell->name);
+ if (klen > bufmax)
+ return 0;
- _leave(" = FAILED");
- return CACHEFS_MATCH_FAILED;
+ memcpy(buffer, cell->name, klen);
+ return klen;
}
-#endif
/*
- * update a cell record in the cache
+ * provide new auxilliary cache data
*/
-#ifdef AFS_CACHING_SUPPORT
-static void afs_cell_cache_update(void *source, void *entry)
+static uint16_t afs_cell_cache_get_aux(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
{
- struct afs_cache_cell *ccell = entry;
- struct afs_cell *cell = source;
+ const struct afs_cell *cell = cookie_netfs_data;
+ uint16_t dlen;
- _enter("%p,%p", source, entry);
+ _enter("%p,%p,%u", cell, buffer, bufmax);
- strncpy(ccell->name, cell->name, sizeof(ccell->name));
+ dlen = cell->vl_naddrs * sizeof(cell->vl_addrs[0]);
+ dlen = min(dlen, bufmax);
+ dlen &= ~(sizeof(cell->vl_addrs[0]) - 1);
- memcpy(ccell->vl_servers,
- cell->vl_addrs,
- min(sizeof(ccell->vl_servers), sizeof(cell->vl_addrs)));
+ memcpy(buffer, cell->vl_addrs, dlen);
+ return dlen;
+}
+/*
+ * check that the auxilliary data indicates that the entry is still valid
+ */
+static enum fscache_checkaux afs_cell_cache_check_aux(void *cookie_netfs_data,
+ const void *buffer,
+ uint16_t buflen)
+{
+ _leave(" = OKAY");
+ return FSCACHE_CHECKAUX_OKAY;
}
-#endif
-
-#ifdef AFS_CACHING_SUPPORT
-static cachefs_match_val_t afs_vlocation_cache_match(void *target,
- const void *entry);
-static void afs_vlocation_cache_update(void *source, void *entry);
-
-struct cachefs_index_def afs_vlocation_cache_index_def = {
- .name = "vldb",
- .data_size = sizeof(struct afs_cache_vlocation),
- .keys[0] = { CACHEFS_INDEX_KEYS_ASCIIZ, 64 },
- .match = afs_vlocation_cache_match,
- .update = afs_vlocation_cache_update,
-};
-#endif
+/*****************************************************************************/
/*
- * match a VLDB record stored in the cache
- * - may also load target from entry
+ * set the key for the index entry
*/
-#ifdef AFS_CACHING_SUPPORT
-static cachefs_match_val_t afs_vlocation_cache_match(void *target,
- const void *entry)
+static uint16_t afs_vlocation_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
{
- const struct afs_cache_vlocation *vldb = entry;
- struct afs_vlocation *vlocation = target;
+ const struct afs_vlocation *vlocation = cookie_netfs_data;
+ uint16_t klen;
+
+ _enter("{%s},%p,%u", vlocation->vldb.name, buffer, bufmax);
+
+ klen = strnlen(vlocation->vldb.name, sizeof(vlocation->vldb.name));
+ if (klen > bufmax)
+ return 0;
- _enter("{%s},{%s}", vlocation->vldb.name, vldb->name);
+ memcpy(buffer, vlocation->vldb.name, klen);
- if (strncmp(vlocation->vldb.name, vldb->name, sizeof(vldb->name)) == 0
- ) {
- if (!vlocation->valid ||
- vlocation->vldb.rtime == vldb->rtime
+ _leave(" = %u", klen);
+ return klen;
+}
+
+/*
+ * provide new auxilliary cache data
+ */
+static uint16_t afs_vlocation_cache_get_aux(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
+{
+ const struct afs_vlocation *vlocation = cookie_netfs_data;
+ uint16_t dlen;
+
+ _enter("{%s},%p,%u", vlocation->vldb.name, buffer, bufmax);
+
+ dlen = sizeof(struct afs_cache_vlocation);
+ dlen -= offsetof(struct afs_cache_vlocation, nservers);
+ if (dlen > bufmax)
+ return 0;
+
+ memcpy(buffer, (uint8_t *)&vlocation->vldb.nservers, dlen);
+
+ _leave(" = %u", dlen);
+ return dlen;
+}
+
+/*
+ * check that the auxilliary data indicates that the entry is still valid
+ */
+static
+enum fscache_checkaux afs_vlocation_cache_check_aux(void *cookie_netfs_data,
+ const void *buffer,
+ uint16_t buflen)
+{
+ const struct afs_cache_vlocation *cvldb;
+ struct afs_vlocation *vlocation = cookie_netfs_data;
+ uint16_t dlen;
+
+ _enter("{%s},%p,%u", vlocation->vldb.name, buffer, buflen);
+
+ /* check the size of the data is what we're expecting */
+ dlen = sizeof(struct afs_cache_vlocation);
+ dlen -= offsetof(struct afs_cache_vlocation, nservers);
+ if (dlen != buflen)
+ return FSCACHE_CHECKAUX_OBSOLETE;
+
+ cvldb = container_of(buffer, struct afs_cache_vlocation, nservers);
+
+ /* if what's on disk is more valid than what's in memory, then use the
+ * VL record from the cache */
+ if (!vlocation->valid || vlocation->vldb.rtime == cvldb->rtime) {
+ memcpy((uint8_t *)&vlocation->vldb.nservers, buffer, dlen);
+ vlocation->valid = 1;
+ _leave(" = SUCCESS [c->m]");
+ return FSCACHE_CHECKAUX_OKAY;
+ }
+
+ /* need to update the cache if the cached info differs */
+ if (memcmp(&vlocation->vldb, buffer, dlen) != 0) {
+ /* delete if the volume IDs for this name differ */
+ if (memcmp(&vlocation->vldb.vid, &cvldb->vid,
+ sizeof(cvldb->vid)) != 0
) {
- vlocation->vldb = *vldb;
- vlocation->valid = 1;
- _leave(" = SUCCESS [c->m]");
- return CACHEFS_MATCH_SUCCESS;
- } else if (memcmp(&vlocation->vldb, vldb, sizeof(*vldb)) != 0) {
- /* delete if VIDs for this name differ */
- if (memcmp(&vlocation->vldb.vid,
- &vldb->vid,
- sizeof(vldb->vid)) != 0) {
- _leave(" = DELETE");
- return CACHEFS_MATCH_SUCCESS_DELETE;
- }
-
- _leave(" = UPDATE");
- return CACHEFS_MATCH_SUCCESS_UPDATE;
- } else {
- _leave(" = SUCCESS");
- return CACHEFS_MATCH_SUCCESS;
+ _leave(" = OBSOLETE");
+ return FSCACHE_CHECKAUX_OBSOLETE;
}
+
+ _leave(" = UPDATE");
+ return FSCACHE_CHECKAUX_NEEDS_UPDATE;
}
- _leave(" = FAILED");
- return CACHEFS_MATCH_FAILED;
+ _leave(" = OKAY");
+ return FSCACHE_CHECKAUX_OKAY;
}
-#endif
+/*****************************************************************************/
/*
- * update a VLDB record stored in the cache
+ * set the key for the volume index entry
*/
-#ifdef AFS_CACHING_SUPPORT
-static void afs_vlocation_cache_update(void *source, void *entry)
+static uint16_t afs_volume_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
{
- struct afs_cache_vlocation *vldb = entry;
- struct afs_vlocation *vlocation = source;
+ const struct afs_volume *volume = cookie_netfs_data;
+ uint16_t klen;
+
+ _enter("{%u},%p,%u", volume->type, buffer, bufmax);
+
+ klen = sizeof(volume->type);
+ if (klen > bufmax)
+ return 0;
- _enter("");
+ memcpy(buffer, &volume->type, sizeof(volume->type));
+
+ _leave(" = %u", klen);
+ return klen;
- *vldb = vlocation->vldb;
}
-#endif
-
-#ifdef AFS_CACHING_SUPPORT
-static cachefs_match_val_t afs_volume_cache_match(void *target,
- const void *entry);
-static void afs_volume_cache_update(void *source, void *entry);
-
-struct cachefs_index_def afs_volume_cache_index_def = {
- .name = "volume",
- .data_size = sizeof(struct afs_cache_vhash),
- .keys[0] = { CACHEFS_INDEX_KEYS_BIN, 1 },
- .keys[1] = { CACHEFS_INDEX_KEYS_BIN, 1 },
- .match = afs_volume_cache_match,
- .update = afs_volume_cache_update,
-};
-#endif
+/*****************************************************************************/
/*
- * match a volume hash record stored in the cache
+ * set the key for the index entry
*/
-#ifdef AFS_CACHING_SUPPORT
-static cachefs_match_val_t afs_volume_cache_match(void *target,
- const void *entry)
+static uint16_t afs_vnode_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
{
- const struct afs_cache_vhash *vhash = entry;
- struct afs_volume *volume = target;
+ const struct afs_vnode *vnode = cookie_netfs_data;
+ uint16_t klen;
- _enter("{%u},{%u}", volume->type, vhash->vtype);
+ _enter("{%x,%x,%llx},%p,%u",
+ vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
+ buffer, bufmax);
- if (volume->type == vhash->vtype) {
- _leave(" = SUCCESS");
- return CACHEFS_MATCH_SUCCESS;
- }
+ klen = sizeof(vnode->fid.vnode);
+ if (klen > bufmax)
+ return 0;
+
+ memcpy(buffer, &vnode->fid.vnode, sizeof(vnode->fid.vnode));
- _leave(" = FAILED");
- return CACHEFS_MATCH_FAILED;
+ _leave(" = %u", klen);
+ return klen;
}
-#endif
/*
- * update a volume hash record stored in the cache
+ * provide updated file attributes
*/
-#ifdef AFS_CACHING_SUPPORT
-static void afs_volume_cache_update(void *source, void *entry)
+static void afs_vnode_cache_get_attr(const void *cookie_netfs_data,
+ uint64_t *size)
{
- struct afs_cache_vhash *vhash = entry;
- struct afs_volume *volume = source;
+ const struct afs_vnode *vnode = cookie_netfs_data;
- _enter("");
+ _enter("{%x,%x,%llx},",
+ vnode->fid.vnode, vnode->fid.unique,
+ vnode->status.data_version);
- vhash->vtype = volume->type;
+ *size = vnode->status.size;
}
-#endif
-
-#ifdef AFS_CACHING_SUPPORT
-static cachefs_match_val_t afs_vnode_cache_match(void *target,
- const void *entry);
-static void afs_vnode_cache_update(void *source, void *entry);
-
-struct cachefs_index_def afs_vnode_cache_index_def = {
- .name = "vnode",
- .data_size = sizeof(struct afs_cache_vnode),
- .keys[0] = { CACHEFS_INDEX_KEYS_BIN, 4 },
- .match = afs_vnode_cache_match,
- .update = afs_vnode_cache_update,
-};
-#endif
/*
- * match a vnode record stored in the cache
+ * provide new auxilliary cache data
+ */
+static uint16_t afs_vnode_cache_get_aux(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
+{
+ const struct afs_vnode *vnode = cookie_netfs_data;
+ uint16_t dlen;
+
+ _enter("{%x,%x,%Lx},%p,%u",
+ vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
+ buffer, bufmax);
+
+ dlen = sizeof(vnode->fid.unique) + sizeof(vnode->status.data_version);
+ if (dlen > bufmax)
+ return 0;
+
+ memcpy(buffer, &vnode->fid.unique, sizeof(vnode->fid.unique));
+ buffer += sizeof(vnode->fid.unique);
+ memcpy(buffer, &vnode->status.data_version,
+ sizeof(vnode->status.data_version));
+
+ _leave(" = %u", dlen);
+ return dlen;
+}
+
+/*
+ * check that the auxilliary data indicates that the entry is still valid
*/
-#ifdef AFS_CACHING_SUPPORT
-static cachefs_match_val_t afs_vnode_cache_match(void *target,
- const void *entry)
+static enum fscache_checkaux afs_vnode_cache_check_aux(void *cookie_netfs_data,
+ const void *buffer,
+ uint16_t buflen)
{
- const struct afs_cache_vnode *cvnode = entry;
- struct afs_vnode *vnode = target;
-
- _enter("{%x,%x,%Lx},{%x,%x,%Lx}",
- vnode->fid.vnode,
- vnode->fid.unique,
- vnode->status.version,
- cvnode->vnode_id,
- cvnode->vnode_unique,
- cvnode->data_version);
-
- if (vnode->fid.vnode != cvnode->vnode_id) {
- _leave(" = FAILED");
- return CACHEFS_MATCH_FAILED;
+ struct afs_vnode *vnode = cookie_netfs_data;
+ uint16_t dlen;
+
+ _enter("{%x,%x,%llx},%p,%u",
+ vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
+ buffer, buflen);
+
+ /* check the size of the data is what we're expecting */
+ dlen = sizeof(vnode->fid.unique) + sizeof(vnode->status.data_version);
+ if (dlen != buflen) {
+ _leave(" = OBSOLETE [len %hx != %hx]", dlen, buflen);
+ return FSCACHE_CHECKAUX_OBSOLETE;
}
- if (vnode->fid.unique != cvnode->vnode_unique ||
- vnode->status.version != cvnode->data_version) {
- _leave(" = DELETE");
- return CACHEFS_MATCH_SUCCESS_DELETE;
+ if (memcmp(buffer,
+ &vnode->fid.unique,
+ sizeof(vnode->fid.unique)
+ ) != 0) {
+ unsigned unique;
+
+ memcpy(&unique, buffer, sizeof(unique));
+
+ _leave(" = OBSOLETE [uniq %x != %x]",
+ unique, vnode->fid.unique);
+ return FSCACHE_CHECKAUX_OBSOLETE;
+ }
+
+ if (memcmp(buffer + sizeof(vnode->fid.unique),
+ &vnode->status.data_version,
+ sizeof(vnode->status.data_version)
+ ) != 0) {
+ afs_dataversion_t version;
+
+ memcpy(&version, buffer + sizeof(vnode->fid.unique),
+ sizeof(version));
+
+ _leave(" = OBSOLETE [vers %llx != %llx]",
+ version, vnode->status.data_version);
+ return FSCACHE_CHECKAUX_OBSOLETE;
}
_leave(" = SUCCESS");
- return CACHEFS_MATCH_SUCCESS;
+ return FSCACHE_CHECKAUX_OKAY;
}
-#endif
/*
- * update a vnode record stored in the cache
+ * indication the cookie is no longer uncached
+ * - this function is called when the backing store currently caching a cookie
+ * is removed
+ * - the netfs should use this to clean up any markers indicating cached pages
+ * - this is mandatory for any object that may have data
*/
-#ifdef AFS_CACHING_SUPPORT
-static void afs_vnode_cache_update(void *source, void *entry)
+static void afs_vnode_cache_now_uncached(void *cookie_netfs_data)
{
- struct afs_cache_vnode *cvnode = entry;
- struct afs_vnode *vnode = source;
+ struct afs_vnode *vnode = cookie_netfs_data;
+ struct pagevec pvec;
+ pgoff_t first;
+ int loop, nr_pages;
+
+ _enter("{%x,%x,%Lx}",
+ vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version);
+
+ pagevec_init(&pvec, 0);
+ first = 0;
+
+ for (;;) {
+ /* grab a bunch of pages to clean */
+ nr_pages = pagevec_lookup(&pvec, vnode->vfs_inode.i_mapping,
+ first,
+ PAGEVEC_SIZE - pagevec_count(&pvec));
+ if (!nr_pages)
+ break;
- _enter("");
+ for (loop = 0; loop < nr_pages; loop++)
+ ClearPageFsCache(pvec.pages[loop]);
+
+ first = pvec.pages[nr_pages - 1]->index + 1;
+
+ pvec.nr = nr_pages;
+ pagevec_release(&pvec);
+ cond_resched();
+ }
- cvnode->vnode_id = vnode->fid.vnode;
- cvnode->vnode_unique = vnode->fid.unique;
- cvnode->data_version = vnode->status.version;
+ _leave("");
}
-#endif
static int afs_releasepage(struct page *page, gfp_t gfp_flags);
static int afs_launder_page(struct page *page);
+static int afs_readpages(struct file *filp, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages);
+
const struct file_operations afs_file_operations = {
.open = afs_open,
.release = afs_release,
const struct address_space_operations afs_fs_aops = {
.readpage = afs_readpage,
+ .readpages = afs_readpages,
.set_page_dirty = afs_set_page_dirty,
.launder_page = afs_launder_page,
.releasepage = afs_releasepage,
/*
* deal with notification that a page was read from the cache
*/
-#ifdef AFS_CACHING_SUPPORT
-static void afs_readpage_read_complete(void *cookie_data,
- struct page *page,
- void *data,
- int error)
+static void afs_file_readpage_read_complete(struct page *page,
+ void *data,
+ int error)
{
- _enter("%p,%p,%p,%d", cookie_data, page, data, error);
+ _enter("%p,%p,%d", page, data, error);
- if (error)
- SetPageError(page);
- else
+ /* if the read completes with an error, we just unlock the page and let
+ * the VM reissue the readpage */
+ if (!error)
SetPageUptodate(page);
unlock_page(page);
-
}
-#endif
-
-/*
- * deal with notification that a page was written to the cache
- */
-#ifdef AFS_CACHING_SUPPORT
-static void afs_readpage_write_complete(void *cookie_data,
- struct page *page,
- void *data,
- int error)
-{
- _enter("%p,%p,%p,%d", cookie_data, page, data, error);
-
- unlock_page(page);
-}
-#endif
/*
* AFS read page from file, directory or symlink
if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
goto error;
-#ifdef AFS_CACHING_SUPPORT
/* is it cached? */
- ret = cachefs_read_or_alloc_page(vnode->cache,
+#ifdef CONFIG_AFS_FSCACHE
+ ret = fscache_read_or_alloc_page(vnode->cache,
page,
afs_file_readpage_read_complete,
NULL,
#else
ret = -ENOBUFS;
#endif
-
switch (ret) {
- /* read BIO submitted and wb-journal entry found */
- case 1:
- BUG(); // TODO - handle wb-journal match
-
/* read BIO submitted (page in cache) */
case 0:
break;
- /* no page available in cache */
- case -ENOBUFS:
+ /* page not yet cached */
case -ENODATA:
+ _debug("cache said ENODATA");
+ goto go_on;
+
+ /* page will not be cached */
+ case -ENOBUFS:
+ _debug("cache said ENOBUFS");
default:
+ go_on:
offset = page->index << PAGE_CACHE_SHIFT;
len = min_t(size_t, i_size_read(inode) - offset, PAGE_SIZE);
set_bit(AFS_VNODE_DELETED, &vnode->flags);
ret = -ESTALE;
}
-#ifdef AFS_CACHING_SUPPORT
- cachefs_uncache_page(vnode->cache, page);
+
+#ifdef CONFIG_AFS_FSCACHE
+ fscache_uncache_page(vnode->cache, page);
#endif
+ BUG_ON(PageFsCache(page));
goto error;
}
SetPageUptodate(page);
-#ifdef AFS_CACHING_SUPPORT
- if (cachefs_write_page(vnode->cache,
- page,
- afs_file_readpage_write_complete,
- NULL,
- GFP_KERNEL) != 0
- ) {
- cachefs_uncache_page(vnode->cache, page);
- unlock_page(page);
+ /* send the page to the cache */
+#ifdef CONFIG_AFS_FSCACHE
+ if (PageFsCache(page) &&
+ fscache_write_page(vnode->cache, page, GFP_KERNEL) != 0) {
+ fscache_uncache_page(vnode->cache, page);
+ BUG_ON(PageFsCache(page));
}
-#else
- unlock_page(page);
#endif
+ unlock_page(page);
}
_leave(" = 0");
}
/*
- * invalidate part or all of a page
+ * read a set of pages
*/
-static void afs_invalidatepage(struct page *page, unsigned long offset)
+static int afs_readpages(struct file *file, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
{
- int ret = 1;
+ struct afs_vnode *vnode;
+ int ret = 0;
- _enter("{%lu},%lu", page->index, offset);
+ _enter(",{%lu},,%d", mapping->host->i_ino, nr_pages);
- BUG_ON(!PageLocked(page));
+ vnode = AFS_FS_I(mapping->host);
+ if (vnode->flags & AFS_VNODE_DELETED) {
+ _leave(" = -ESTALE");
+ return -ESTALE;
+ }
- if (PagePrivate(page)) {
- /* We release buffers only if the entire page is being
- * invalidated.
- * The get_block cached value has been unconditionally
- * invalidated, so real IO is not possible anymore.
- */
- if (offset == 0) {
- BUG_ON(!PageLocked(page));
-
- ret = 0;
- if (!PageWriteback(page))
- ret = page->mapping->a_ops->releasepage(page,
- 0);
- /* possibly should BUG_ON(!ret); - neilb */
- }
+ /* attempt to read as many of the pages as possible */
+#ifdef CONFIG_AFS_FSCACHE
+ ret = fscache_read_or_alloc_pages(vnode->cache,
+ mapping,
+ pages,
+ &nr_pages,
+ afs_file_readpage_read_complete,
+ NULL,
+ mapping_gfp_mask(mapping));
+#else
+ ret = -ENOBUFS;
+#endif
+
+ switch (ret) {
+ /* all pages are being read from the cache */
+ case 0:
+ BUG_ON(!list_empty(pages));
+ BUG_ON(nr_pages != 0);
+ _leave(" = 0 [reading all]");
+ return 0;
+
+ /* there were pages that couldn't be read from the cache */
+ case -ENODATA:
+ case -ENOBUFS:
+ break;
+
+ /* other error */
+ default:
+ _leave(" = %d", ret);
+ return ret;
}
- _leave(" = %d", ret);
+ /* load the missing pages from the network */
+ ret = read_cache_pages(mapping, pages, (void *) afs_readpage, file);
+
+ _leave(" = %d [netting]", ret);
+ return ret;
}
/*
}
/*
- * release a page and cleanup its private data
+ * invalidate part or all of a page
+ * - release a page and clean up its private data if offset is 0 (indicating
+ * the entire page)
+ */
+static void afs_invalidatepage(struct page *page, unsigned long offset)
+{
+ struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
+
+ _enter("{%lu},%lu", page->index, offset);
+
+ BUG_ON(!PageLocked(page));
+
+ /* we clean up only if the entire page is being invalidated */
+ if (offset == 0) {
+#ifdef CONFIG_AFS_FSCACHE
+ if (PageFsCache(page)) {
+ struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
+ fscache_wait_on_page_write(vnode->cache, page);
+ fscache_uncache_page(vnode->cache, page);
+ ClearPageFsCache(page);
+ }
+#endif
+
+ if (PagePrivate(page)) {
+ if (wb && !PageWriteback(page)) {
+ set_page_private(page, 0);
+ afs_put_writeback(wb);
+ }
+
+ if (!page_private(page))
+ ClearPagePrivate(page);
+ }
+ }
+
+ _leave("");
+}
+
+/*
+ * release a page and clean up its private state if it's not busy
+ * - return true if the page can now be released, false if not
*/
static int afs_releasepage(struct page *page, gfp_t gfp_flags)
{
+ struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
- struct afs_writeback *wb;
_enter("{{%x:%u}[%lu],%lx},%x",
vnode->fid.vid, vnode->fid.vnode, page->index, page->flags,
gfp_flags);
+ /* deny if page is being written to the cache and the caller hasn't
+ * elected to wait */
+#ifdef CONFIG_AFS_FSCACHE
+ if (PageFsCache(page)) {
+ if (fscache_check_page_write(vnode->cache, page)) {
+ if (!(gfp_flags & __GFP_WAIT)) {
+ _leave(" = F [cache busy]");
+ return 0;
+ }
+ fscache_wait_on_page_write(vnode->cache, page);
+ }
+
+ fscache_uncache_page(vnode->cache, page);
+ ClearPageFsCache(page);
+ }
+#endif
+
if (PagePrivate(page)) {
- wb = (struct afs_writeback *) page_private(page);
- ASSERT(wb != NULL);
- set_page_private(page, 0);
+ if (wb) {
+ set_page_private(page, 0);
+ afs_put_writeback(wb);
+ }
ClearPagePrivate(page);
- afs_put_writeback(wb);
}
- _leave(" = 0");
- return 0;
+ /* indicate that the page can be released */
+ _leave(" = T");
+ return 1;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / commitdiff