Konstantin Belousov 91e9474552 Make it possible to atomically resume writes on the mount and account ... the write start, by adding a variation of the vfs_write_resume(9) which accepts flags. Use the new function to prevent a deadlock between parallel suspension and snapshotting a UFS mount. The ffs_snapshot() code performed vfs_write_resume() followed by vn_start_write() while owning the snaplock. If the suspension intervene between resume and vn_start_write(), the deadlock occured after the suspending thread tried to lock the snaplock, most typically during the write in the ffs_copyonwrite(). Reported and tested by: Andreas Longwitz <longwitz@incore.de> Reviewed by: mckusick MFC after: 2 weeks X-MFC-note: make the vfs_write_resume(9) function a macro after the MFC, in HEAD		2012-12-28 23:08:30 +00:00
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ffs	Make it possible to atomically resume writes on the mount and account	2012-12-28 23:08:30 +00:00
ufs	Fix a typo, resulting in the NULL pointer dereference.	2012-12-15 02:03:59 +00:00