From b0895513f499b8f786d292ce48589ca210ca1d6e Mon Sep 17 00:00:00 2001 From: "J. R. Okajima" Date: Wed, 17 Jun 2009 01:16:50 +0900 Subject: remove unlock_kernel() left accidentally commit 337eb00a2c3a421999c39c94ce7e33545ee8baa7 Push BKL down into ->remount_fs() and commit 4aa98cf768b6f2ea4b204620d949a665959214f6 Push BKL down into do_remount_sb() were uncorrectly merged. The former removes one pair of lock/unlock_kernel(), but the latter adds several unlock_kernel(). Finally a few unlock_kernel() calls left. Signed-off-by: J. R. Okajima Signed-off-by: Al Viro --- fs/super.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) (limited to 'fs/super.c') diff --git a/fs/super.c b/fs/super.c index 83b47416d006..d40d53a22fb5 100644 --- a/fs/super.c +++ b/fs/super.c @@ -545,24 +545,18 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force) if ((flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY)) { if (force) mark_files_ro(sb); - else if (!fs_may_remount_ro(sb)) { - unlock_kernel(); + else if (!fs_may_remount_ro(sb)) return -EBUSY; - } retval = vfs_dq_off(sb, 1); - if (retval < 0 && retval != -ENOSYS) { - unlock_kernel(); + if (retval < 0 && retval != -ENOSYS) return -EBUSY; - } } remount_rw = !(flags & MS_RDONLY) && (sb->s_flags & MS_RDONLY); if (sb->s_op->remount_fs) { retval = sb->s_op->remount_fs(sb, &flags, data); - if (retval) { - unlock_kernel(); + if (retval) return retval; - } } sb->s_flags = (sb->s_flags & ~MS_RMT_MASK) | (flags & MS_RMT_MASK); if (remount_rw) -- cgit v1.2.3 From c63e09ecccb50f930e899d7005edc5411ee86d4f Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 24 Jun 2009 02:05:18 -0400 Subject: Make allocation of anon devices cheaper Standard trick - add a new variable (start) such that for each n < start n is known to be busy. Allocation can skip checking everything in [0..start) and if it returns n, we can set start to n + 1. Freeing below start sets start to what we'd just freed. Of course, it still sucks if we do something like free 0 allocate allocate in a loop - still O(n^2) time. However, on saner loads it improves the things a lot and the entire thing is not worth the trouble of switching to something with better worst-case behaviour. Signed-off-by: Al Viro --- fs/super.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'fs/super.c') diff --git a/fs/super.c b/fs/super.c index d40d53a22fb5..808ffd59e01b 100644 --- a/fs/super.c +++ b/fs/super.c @@ -608,6 +608,7 @@ void emergency_remount(void) static DEFINE_IDA(unnamed_dev_ida); static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */ +static int unnamed_dev_start = 0; /* don't bother trying below it */ int set_anon_super(struct super_block *s, void *data) { @@ -618,7 +619,8 @@ int set_anon_super(struct super_block *s, void *data) if (ida_pre_get(&unnamed_dev_ida, GFP_ATOMIC) == 0) return -ENOMEM; spin_lock(&unnamed_dev_lock); - error = ida_get_new(&unnamed_dev_ida, &dev); + error = ida_get_new_above(&unnamed_dev_ida, unnamed_dev_start, &dev); + unnamed_dev_start = dev + 1; spin_unlock(&unnamed_dev_lock); if (error == -EAGAIN) /* We raced and lost with another CPU. */ @@ -629,6 +631,7 @@ int set_anon_super(struct super_block *s, void *data) if ((dev & MAX_ID_MASK) == (1 << MINORBITS)) { spin_lock(&unnamed_dev_lock); ida_remove(&unnamed_dev_ida, dev); + unnamed_dev_start = dev; spin_unlock(&unnamed_dev_lock); return -EMFILE; } @@ -645,6 +648,8 @@ void kill_anon_super(struct super_block *sb) generic_shutdown_super(sb); spin_lock(&unnamed_dev_lock); ida_remove(&unnamed_dev_ida, slot); + if (slot < unnamed_dev_start) + unnamed_dev_start = slot; spin_unlock(&unnamed_dev_lock); } -- cgit v1.2.3 From f21f62208a6f60e2e05440b2e438d9541822dc4d Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 24 Jun 2009 03:12:00 -0400 Subject: ... and the same for vfsmount id/mount group id Signed-off-by: Al Viro --- fs/super.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'fs/super.c') diff --git a/fs/super.c b/fs/super.c index 808ffd59e01b..2761d3e22ed9 100644 --- a/fs/super.c +++ b/fs/super.c @@ -620,7 +620,8 @@ int set_anon_super(struct super_block *s, void *data) return -ENOMEM; spin_lock(&unnamed_dev_lock); error = ida_get_new_above(&unnamed_dev_ida, unnamed_dev_start, &dev); - unnamed_dev_start = dev + 1; + if (!error) + unnamed_dev_start = dev + 1; spin_unlock(&unnamed_dev_lock); if (error == -EAGAIN) /* We raced and lost with another CPU. */ @@ -631,7 +632,8 @@ int set_anon_super(struct super_block *s, void *data) if ((dev & MAX_ID_MASK) == (1 << MINORBITS)) { spin_lock(&unnamed_dev_lock); ida_remove(&unnamed_dev_ida, dev); - unnamed_dev_start = dev; + if (unnamed_dev_start > dev) + unnamed_dev_start = dev; spin_unlock(&unnamed_dev_lock); return -EMFILE; } -- cgit v1.2.3