From 454e2398be9b9fa30433fccc548db34d19aa9958 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 23 Jun 2006 02:02:57 -0700 Subject: [PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells Acked-by: Al Viro Cc: Nathan Scott Cc: Roland Dreier Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/super.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'fs/ocfs2/super.c') diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index 949b3dac30f..788b8b50dc4 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -672,12 +672,14 @@ read_super_error: return status; } -static struct super_block *ocfs2_get_sb(struct file_system_type *fs_type, - int flags, - const char *dev_name, - void *data) +static int ocfs2_get_sb(struct file_system_type *fs_type, + int flags, + const char *dev_name, + void *data, + struct vfsmount *mnt) { - return get_sb_bdev(fs_type, flags, dev_name, data, ocfs2_fill_super); + return get_sb_bdev(fs_type, flags, dev_name, data, ocfs2_fill_super, + mnt); } static struct file_system_type ocfs2_fs_type = { -- cgit v1.2.3 From 726c334223180e3c0197cc980a432681370d4baf Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 23 Jun 2006 02:02:58 -0700 Subject: [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry Give the statfs superblock operation a dentry pointer rather than a superblock pointer. This complements the get_sb() patch. That reduced the significance of sb->s_root, allowing NFS to place a fake root there. However, NFS does require a dentry to use as a target for the statfs operation. This permits the root in the vfsmount to be used instead. linux/mount.h has been added where necessary to make allyesconfig build successfully. Interest has also been expressed for use with the FUSE and XFS filesystems. Signed-off-by: David Howells Acked-by: Al Viro Cc: Nathan Scott Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/super.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'fs/ocfs2/super.c') diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index 788b8b50dc4..cdf73393f09 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -100,7 +100,7 @@ static int ocfs2_initialize_mem_caches(void); static void ocfs2_free_mem_caches(void); static void ocfs2_delete_osb(struct ocfs2_super *osb); -static int ocfs2_statfs(struct super_block *sb, struct kstatfs *buf); +static int ocfs2_statfs(struct dentry *dentry, struct kstatfs *buf); static int ocfs2_sync_fs(struct super_block *sb, int wait); @@ -857,7 +857,7 @@ static void ocfs2_put_super(struct super_block *sb) mlog_exit_void(); } -static int ocfs2_statfs(struct super_block *sb, struct kstatfs *buf) +static int ocfs2_statfs(struct dentry *dentry, struct kstatfs *buf) { struct ocfs2_super *osb; u32 numbits, freebits; @@ -866,9 +866,9 @@ static int ocfs2_statfs(struct super_block *sb, struct kstatfs *buf) struct buffer_head *bh = NULL; struct inode *inode = NULL; - mlog_entry("(%p, %p)\n", sb, buf); + mlog_entry("(%p, %p)\n", dentry->d_sb, buf); - osb = OCFS2_SB(sb); + osb = OCFS2_SB(dentry->d_sb); inode = ocfs2_get_system_file_inode(osb, GLOBAL_BITMAP_SYSTEM_INODE, @@ -891,7 +891,7 @@ static int ocfs2_statfs(struct super_block *sb, struct kstatfs *buf) freebits = numbits - le32_to_cpu(bm_lock->id1.bitmap1.i_used); buf->f_type = OCFS2_SUPER_MAGIC; - buf->f_bsize = sb->s_blocksize; + buf->f_bsize = dentry->d_sb->s_blocksize; buf->f_namelen = OCFS2_MAX_FILENAME_LEN; buf->f_blocks = ((sector_t) numbits) * (osb->s_clustersize >> osb->sb->s_blocksize_bits); -- cgit v1.2.3 From 781ee3e2b1ea41d56ed86ae1c85fc40b7f330205 Mon Sep 17 00:00:00 2001 From: Sunil Mushran Date: Thu, 27 Apr 2006 16:41:31 -0700 Subject: ocfs2: Cleanup message prints Signed-off-by: Sunil Mushran Signed-off-by: Mark Fasheh --- fs/ocfs2/super.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'fs/ocfs2/super.c') diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index cdf73393f09..4e214ecb588 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -642,10 +642,9 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent) ocfs2_complete_mount_recovery(osb); - printk("ocfs2: Mounting device (%u,%u) on (node %d, slot %d) with %s " - "data mode.\n", - MAJOR(sb->s_dev), MINOR(sb->s_dev), osb->node_num, - osb->slot_num, + printk(KERN_INFO "ocfs2: Mounting device (%s) on (node %d, slot %d) " + "with %s data mode.\n", + osb->dev_str, osb->node_num, osb->slot_num, osb->s_mount_opt & OCFS2_MOUNT_DATA_WRITEBACK ? "writeback" : "ordered"); @@ -1020,7 +1019,7 @@ static int ocfs2_fill_local_node_info(struct ocfs2_super *osb) goto bail; } - mlog(ML_NOTICE, "I am node %d\n", osb->node_num); + mlog(0, "I am node %d\n", osb->node_num); status = 0; bail: @@ -1191,8 +1190,8 @@ static void ocfs2_dismount_volume(struct super_block *sb, int mnt_err) atomic_set(&osb->vol_state, VOLUME_DISMOUNTED); - printk("ocfs2: Unmounting device (%u,%u) on (node %d)\n", - MAJOR(osb->sb->s_dev), MINOR(osb->sb->s_dev), osb->node_num); + printk(KERN_INFO "ocfs2: Unmounting device (%s) on (node %d)\n", + osb->dev_str, osb->node_num); ocfs2_delete_osb(osb); kfree(osb); @@ -1327,7 +1326,7 @@ static int ocfs2_initialize_super(struct super_block *sb, status = -EINVAL; goto bail; } - mlog(ML_NOTICE, "max_slots for this device: %u\n", osb->max_slots); + mlog(0, "max_slots for this device: %u\n", osb->max_slots); init_waitqueue_head(&osb->osb_wipe_event); osb->osb_orphan_wipes = kcalloc(osb->max_slots, -- cgit v1.2.3 From a75a6e4c3ada10b15e26f6d12f72c03efde266e0 Mon Sep 17 00:00:00 2001 From: Mark Fasheh Date: Thu, 4 May 2006 11:49:22 -0700 Subject: ocfs2: fix init of uuid_net_key ocfs2_initialize_super() should be copying from the beginning of the uuid. Signed-off-by: Mark Fasheh --- fs/ocfs2/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/ocfs2/super.c') diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index 4e214ecb588..3aa9f18527f 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -1417,7 +1417,7 @@ static int ocfs2_initialize_super(struct super_block *sb, goto bail; } - memcpy(&uuid_net_key, &osb->uuid[i], sizeof(osb->net_key)); + memcpy(&uuid_net_key, osb->uuid, sizeof(uuid_net_key)); osb->net_key = le32_to_cpu(uuid_net_key); strncpy(osb->vol_label, di->id2.i_super.s_label, 63); -- cgit v1.2.3 From 784270435b001164054e803421a624ef1098519d Mon Sep 17 00:00:00 2001 From: Mark Fasheh Date: Thu, 4 May 2006 12:03:26 -0700 Subject: ocfs2: clean up some osb fields Get rid of osb->uuid, osb->proc_sub_dir, and osb->osb_id. Those fields were unused, or could easily be removed. As a result, we also no longer need MAX_OSB_ID or ocfs2_globals_lock. Signed-off-by: Mark Fasheh --- fs/ocfs2/super.c | 34 +--------------------------------- 1 file changed, 1 insertion(+), 33 deletions(-) (limited to 'fs/ocfs2/super.c') diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index 3aa9f18527f..382706a67ff 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -68,13 +68,6 @@ #include "buffer_head_io.h" -/* - * Globals - */ -static spinlock_t ocfs2_globals_lock = SPIN_LOCK_UNLOCKED; - -static u32 osb_id; /* Keeps track of next available OSB Id */ - static kmem_cache_t *ocfs2_inode_cachep = NULL; kmem_cache_t *ocfs2_lock_cache = NULL; @@ -799,10 +792,6 @@ static int __init ocfs2_init(void) goto leave; } - spin_lock(&ocfs2_globals_lock); - osb_id = 0; - spin_unlock(&ocfs2_globals_lock); - ocfs2_debugfs_root = debugfs_create_dir("ocfs2", NULL); if (!ocfs2_debugfs_root) { status = -EFAULT; @@ -1211,8 +1200,6 @@ static int ocfs2_setup_osb_uuid(struct ocfs2_super *osb, const unsigned char *uu if (osb->uuid_str == NULL) return -ENOMEM; - memcpy(osb->uuid, uuid, OCFS2_VOL_UUID_LEN); - for (i = 0, ptr = osb->uuid_str; i < OCFS2_VOL_UUID_LEN; i++) { /* print with null */ ret = snprintf(ptr, 3, "%02X", uuid[i]); @@ -1310,13 +1297,6 @@ static int ocfs2_initialize_super(struct super_block *sb, goto bail; } - osb->uuid = kmalloc(OCFS2_VOL_UUID_LEN, GFP_KERNEL); - if (!osb->uuid) { - mlog(ML_ERROR, "unable to alloc uuid\n"); - status = -ENOMEM; - goto bail; - } - di = (struct ocfs2_dinode *)bh->b_data; osb->max_slots = le16_to_cpu(di->id2.i_super.s_max_slots); @@ -1417,7 +1397,7 @@ static int ocfs2_initialize_super(struct super_block *sb, goto bail; } - memcpy(&uuid_net_key, osb->uuid, sizeof(uuid_net_key)); + memcpy(&uuid_net_key, di->id2.i_super.s_uuid, sizeof(uuid_net_key)); osb->net_key = le32_to_cpu(uuid_net_key); strncpy(osb->vol_label, di->id2.i_super.s_label, 63); @@ -1483,18 +1463,6 @@ static int ocfs2_initialize_super(struct super_block *sb, goto bail; } - /* Link this osb onto the global linked list of all osb structures. */ - /* The Global Link List is mainted for the whole driver . */ - spin_lock(&ocfs2_globals_lock); - osb->osb_id = osb_id; - if (osb_id < OCFS2_MAX_OSB_ID) - osb_id++; - else { - mlog(ML_ERROR, "Too many volumes mounted\n"); - status = -ENOMEM; - } - spin_unlock(&ocfs2_globals_lock); - bail: mlog_exit(status); return status; -- cgit v1.2.3