diff options
Diffstat (limited to 'ext2fs')
| -rw-r--r-- | ext2fs/pager.c | 84 |
1 files changed, 52 insertions, 32 deletions
diff --git a/ext2fs/pager.c b/ext2fs/pager.c index 3130fda4..c34f8cb1 100644 --- a/ext2fs/pager.c +++ b/ext2fs/pager.c @@ -35,34 +35,34 @@ spin_lock_t node_to_page_lock = SPIN_LOCK_INITIALIZER; /* ---------------------------------------------------------------- */ /* Find the location on disk of page OFFSET in NODE. Return the disk block - in BLOCK (if unallocated, then return 0). If *NODE_LOCK is set on return, - then release that mutex after I/O on the data has completed. Set LENGTH - to be the amount of valid data on disk. */ + in BLOCK (if unallocated, then return 0). If *LOCK is 0, then it a reader + lock is aquired on NODE's ALLOC_LOCK before doing anything, and left + locked after return -- even if an error is returned. 0 on success or an + error code otherwise is returned. */ static error_t find_block (struct node *node, vm_offset_t offset, - daddr_t *block, int create, - struct rwlock **node_lock) + daddr_t *block, struct rwlock **lock) { error_t err; char *bptr; - if (!*node_lock) + if (!*lock) { - *node_lock = &node->dn->alloc_lock; - rwlock_reader_lock (*node_lock); + *lock = &node->dn->alloc_lock; + rwlock_reader_lock (*lock); } if (offset + block_size > node->allocsize) return EIO; - err = ext2_getblk (node, offset >> log2_block_size, create, &bptr); + err = ext2_getblk (node, offset >> log2_block_size, 0, &bptr); if (err == EINVAL) /* Don't barf yet if the node is unallocated. */ { *block = 0; err = 0; } - else + else if (err == 0) *block = bptr_block (bptr); return err; @@ -79,7 +79,7 @@ file_pager_read_page (struct node *node, vm_offset_t page, { error_t err; int offs = 0; - struct rwlock *node_lock = NULL; + struct rwlock *lock = NULL; int left = vm_page_size; daddr_t pending_blocks = 0; int num_pending_blocks = 0; @@ -121,7 +121,7 @@ file_pager_read_page (struct node *node, vm_offset_t page, { daddr_t block; - err = find_block (node, page, &block, 0, &node_lock); + err = find_block (node, page, &block, &lock); if (err) break; @@ -142,7 +142,6 @@ file_pager_read_page (struct node *node, vm_offset_t page, err = vm_allocate (mach_task_self (), buf, vm_page_size, 1); if (err) break; - *writelock = 1; } bzero ((char *)*buf + offs, block_size); offs += block_size; @@ -157,8 +156,8 @@ file_pager_read_page (struct node *node, vm_offset_t page, if (!err && num_pending_blocks > 0) do_pending_reads(); - if (node_lock) - rwlock_reader_unlock (node_lock); + if (lock) + rwlock_reader_unlock (lock); return err; } @@ -187,7 +186,7 @@ pending_blocks_write (struct pending_blocks *pb) daddr_t dev_block = pb->block << log2_dev_blocks_per_fs_block; int length = pb->num << log2_block_size; -printf ("Writing %d pending block(s) at %d\n", pb->num, pb->block); +printf ("Writing block %lu[%d]\n", pb->block, pb->num); if (pb->offs > 0) /* Put what we're going to write into a page-aligned buffer. */ @@ -239,7 +238,6 @@ pending_blocks_add (struct pending_blocks *pb, daddr_t block) if (err) return err; pb->block = block; - printf ("Adding pending block %d\n", block); } pb->num++; return 0; @@ -255,7 +253,7 @@ file_pager_write_page (struct node *node, vm_offset_t offset, vm_address_t buf) { error_t err = 0; struct pending_blocks pb; - struct rwlock *node_lock = 0; + struct rwlock *lock = 0; u32 block; int left = vm_page_size; @@ -264,13 +262,15 @@ file_pager_write_page (struct node *node, vm_offset_t offset, vm_address_t buf) if (offset + left > node->allocsize) left = left > node->allocsize - offset; - printf ("Writing file_pager page %d[%d]\n", offset, left); + printf ("Writing file_pager (inode %d) page %d[%d]\n", + node->dn->number, offset, left); while (left > 0) { - err = find_block (node, offset, &block, 1, &node_lock); + err = find_block (node, offset, &block, &lock); if (err) break; + assert (block); pending_blocks_add (&pb, block); offset += block_size; left -= block_size; @@ -279,8 +279,8 @@ file_pager_write_page (struct node *node, vm_offset_t offset, vm_address_t buf) if (!err) pending_blocks_write (&pb); - if (node_lock) - rwlock_reader_unlock (node_lock); + if (lock) + rwlock_reader_unlock (lock); return err; } @@ -333,8 +333,6 @@ disk_pager_write_page (vm_offset_t page, vm_address_t buf) modified = clear_bit (block, modified_global_blocks); spin_unlock (&modified_global_blocks_lock); - printf ("Disk_pager block %d %s\n", block, (modified ? "modified" : "unmodified")); - if (modified) /* This block's been modified, so write it out. */ err = pending_blocks_add (&pb, block); @@ -384,11 +382,9 @@ pager_write_page (struct user_pager_info *pager, vm_offset_t page, /* ---------------------------------------------------------------- */ -/* Implement the pager_unlock_page callback from the pager library. See - <hurd/pager.h> for the interface description. */ +/* Make page PAGE writable. */ error_t -pager_unlock_page (struct user_pager_info *pager, - vm_offset_t address) +pager_unlock_page (struct user_pager_info *pager, vm_offset_t page) { if (pager->type == DISK) return 0; @@ -396,16 +392,26 @@ pager_unlock_page (struct user_pager_info *pager, { error_t err; char *buf; + daddr_t block = page >> log2_block_size; struct node *node = pager->node; struct disknode *dn = node->dn; rwlock_writer_lock (&dn->alloc_lock); - err = diskfs_catch_exception (); + if (!err) - err = ext2_getblk(node, address >> log2_block_size, 1, &buf); - diskfs_end_catch_exception (); + { + int left = vm_page_size; + while (left > 0) + { + err = ext2_getblk(node, block++, 1, &buf); + if (err) + break; + left -= block_size; + } + } + diskfs_end_catch_exception (); rwlock_writer_unlock (&dn->alloc_lock); return err; @@ -414,6 +420,21 @@ pager_unlock_page (struct user_pager_info *pager, /* ---------------------------------------------------------------- */ +/* The user must define this function. Grow the disk allocated to locked node + NODE to be at least SIZE bytes, and set NODE->allocsize to the actual + allocated size. (If the allocated size is already SIZE bytes, do + nothing.) CRED identifies the user responsible for the call. */ +error_t +diskfs_grow (struct node *node, off_t size, struct protid *cred) +{ + assert (!diskfs_readonly); + + if (size > node->allocsize) + node->allocsize = trunc_block (size) + block_size; + else + return 0; +} + /* Implement the pager_report_extent callback from the pager library. See <hurd/pager.h> for the interface description. */ inline error_t @@ -635,4 +656,3 @@ diskfs_sync_everything (int wait) write_all_disknodes (); pager_traverse (sync_one); } - |